Abstract:
Method and system for managing and evaluating life science data. Life Science data is placed in a knowledge base, that may be used for a variety of analysis tasks. Creating a knowledge base from the life science data involves generating two or more nodes indicative of life science data, assigning to one or more pairs of nodes a representation descriptor that corresponds to a relationship between the nodes, and assembling the nodes and the relationship descriptor into a database, such that at least one of the nodes is joined to another node by a representation descriptor. In some embodiments, the representation descriptor includes a case frame that describes the relationships between elements of life science data.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional application No. 60/414,637, entitled “System, Method and Apparatus for Assembling and Mining Life Science Data,” filed Sep. 30, 2002, the disclosure of which is incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The invention relates to the field of data management and evaluation. In particular, the invention relates to the processing and organization of life science data. 
     BACKGROUND 
     Life science information is information relevant to the understanding of the structures, behaviors, operations, maladies, and processes of plant and animal life, and includes the nature of the work that generated it, the identity of the people who generated it, and assessments of its significance and context within the encyclopedic, ever growing life science knowledge-base of mankind. 
     Traditional methods of discerning and understanding the meaning of life science information are breaking down due to the large amount of material that must be absorbed and combined. New and old information are presented and stored in public, publicly accessible, proprietary, and private databases of different structures, printed or electronic journals, scholarly theses, patents, medical records, master files, books, clinical trial files, government data compilations, etc. These information sources exist in different formats, different languages, different data structures, conflicting vocabulary and ontology, and often are presented based on inconsistent and competing theories. The accessibility of these data for study and knowledge mining ranges from completely inaccessible trade secret data, to data available only by subscription, to current data generated by a colleague but not yet communicated, to obscure observations in a language foreign to the reader, to free public information a few clicks away. To form an effective understanding of a biological system, a life science researcher must synthesize information from many of these sources. 
     Understanding biological systems is made more difficult by the interdisciplinary nature of the life sciences. Forming an understanding of a system may require in-depth knowledge of genetics, cell biology, biochemistry, medicine, and many other fields. The literature in these fields often are addressed to specialists who do not frequently communicate outside their specialties: the protein chemist may not talk to and does not read the literature of the epidemiologist; the synthetic chemist may relate poorly to the molecular biologist. 
     Understanding a biological system may require that information of many different types be combined. Life science information may include material on basic chemistry, proteins, cells, tissues, and effects on organisms or population—all of which may be interrelated. These interrelations may be complex, poorly understood, or hidden. 
     Knowledge useful in the development of human therapies and the like is gained by inspired individuals seeking out and combining disparate data and then reasoning from it. Currently, progress is made as scientists locate and access diverse data sources, pose questions, seek other data in an attempt to refine or eliminate a hypothesis or make a connection, and devise and conduct new experiments. The scientist then publishes or otherwise records his new data, exposing it for review, criticism, and use by others. As knowledge increases, it become apparent that no person can possibly access, much less assimilate, all the available data in any field. Furthermore, the amount of data generated in the life sciences is increasing dramatically, with no end in sight. Those seeking new insights and new knowledge are presented with the ever more difficult task of connecting the right data from mountains of information gleaned from vastly different sources. Thus, to the extent our current system of generating and recording life science data has been developed to permit knowledge mining, it is clearly far from optimal, and significant new efficiencies should be available. 
     What is needed is a way to assemble and store vast amounts of life science information, and to make that information available in a manner that enhances understanding of the interrelationships within the information. It would be desirable to provide a system and methods that allow researchers to assemble life science data and mine information in a comprehensive manner that facilitates the understanding and revelation of the possibly hidden interactions of a biological system. 
     SUMMARY OF THE INVENTION 
     The present invention proposes and enables a new paradigm for the recordation, organization, access, and application of life science data. The method and program enables establishment and ongoing development of a systematic, ontologically consistent, flexible, optimally accessible, evolving, organic, life science knowledge base. A knowledge base according to embodiments of the invention represents and stores biological information of many different types, from many different sources. The knowledge base represents and stores information on many types of relationships within the life science information. 
     A knowledge base according to embodiments of the invention places life science information into a form that exposes the relationships within the information, facilitates efficient knowledge mining, and makes the information more readily comprehensible and available. Such a life science knowledge base can be used in a manner similar to a library, providing a way for researchers, physicians, students, drug discovery companies, and many others to access life science information in a way that enhances the understanding of the information. 
     The knowledge base may be continuously built up and refined, to provide a complete electronic paradigm for harmonizing the vast array of life science information. It is envisioned that a knowledge base according to an embodiment of the invention could eventually incorporate the entirety of human life science knowledge from its finest detail to its global effect. 
     In one aspect, the invention provides a method of assembling a life science knowledge base by generating two or more nodes indicative of life science data using a life science taxonomy, assigning to one or more pairs of nodes a representation descriptor that corresponds to a relationship between a pair of nodes, and assembling two or more nodes and one or more representation descriptors into an electronic database, such that at least one of the nodes is joined to another node by a representation descriptor. In some embodiments, the representations descriptors are themselves nodes, and can be joined to other nodes by representation descriptors. 
     In some embodiments, the method includes the step of receiving life science data, and generating the two or more nodes is based at least in part on the received life science data. In certain such embodiments, receiving life science data includes collecting life science data using a software agent. In some embodiments, receiving life science data further includes receiving one or more of metadata and context data. 
     In some embodiments, the life science data includes information representative of a molecule, biological structure, physiological condition, trait, or phenotype. In some embodiments, the life science data includes a descriptor of the condition, location, amount, or substructure of a molecule, biological structure, physiological condition, trait, or phenotype. 
     In some embodiments the step of generating two or more nodes includes reformatting at least a portion of the life science data. 
     In some embodiments, one or more of the representation descriptors include a case frame. 
     Some embodiments include a step of providing an ontology for use with the representation descriptors, and the step of assigning a representation descriptor to one or more pairs of nodes is based on the ontology. 
     Some embodiments include the step of segregating the electronic database into two or more sectors, such that access may be restricted to one or more selected sectors. 
     In another aspect, the invention provides an article of manufacture having a computer-readable program carrier with computer-readable instructions embodied thereon for performing the methods described above. 
     In another aspect, the invention provides a system for assembling a life science knowledge base. The system includes a data collector configured to receive life science data and to generate nodes based on the life science data. The system also includes a relationship generator configured to assign a relationship descriptor to a pair of nodes, the representation descriptor corresponding to a relationship between a pair of nodes. The system further includes a knowledge assembler configured to assemble two or more nodes and one or more representation descriptors assigned to one or more pairs of the two or more nodes into an electronic database such that each of the two or more nodes are joined to another node by a representation descriptor. 
     In some embodiments, the system also includes a graphical user interface configured to permit a user to query the electronic database at least on the relationship between at least two nodes. 
     In some embodiments, the system includes a data input interface configured to permit a user to submit life science data to the data collector. In some such embodiments, the data input interface is further configured to permit a user to assign a representation descriptor to a pair of nodes in the electronic database. In some embodiments, the data input interface may be configured to permit a user to create, replace, update, and delete nodes and representation descriptors. 
     In some embodiments, the system also includes an access manager configured to restrict access of a user to one or more portions of the electronic database. 
     In some embodiments, the system further includes a software agent in electronic communication with the data collector, wherein the software agent is configured to collect life science data. 
     In some embodiments, the life science data includes information representative of a molecule, biological structure, physiological condition, trait, or phenotype. In some embodiments, the life science data includes a descriptor of the condition, location, amount, or substructure of a molecule, biological structure, physiological condition trait or phenotype. 
     Is some embodiments, the system also includes a library of machine-readable representation descriptors in electronic communication with the relationship generator. The relationship descriptors in some embodiments correspond to an epistemological relationship between a pair of nodes. In some embodiments, one or more of the representation descriptors includes a case frame. 
     In another aspect, the invention provides a computer program product that includes an electronic database storing a plurality of case statements, each case statement comprising an object identifier, a relationship connector, and a biological object identifier, wherein the relationship connector is based on a life science ontology. 
     In some embodiments, a set of the case statements define a biological function. In some such embodiments, the biological function involves a chemical reaction. In some embodiments, the biological function involves transport. In some embodiments, the biological function involves digestion of a biomolecule. 
     In some embodiments, the biological object identifier identifies a biomolecule. In some embodiments, the biological object identifier identifies a biological function. 
     In some embodiments, the relationship connector represents an identity relationship. In some embodiments, the relationship connector represents a product relationship. In some embodiments, the relationship connector represents a substrate relationship. In some embodiments, the relationship connector represents an enzymatic relationship. 
     In some embodiments, the product also includes a graphical user interface configured to permit a user to query the database at least on the relationship between biological object identifiers. 
     In some embodiments, the product further includes a data input interface configured to permit a user to create case statements. 
     In another aspect, the invention provides an article of manufacture where the functionality of one or more of the methods of the invention are embedded on a computer-readable program means, such as, but not limited to, a floppy disk, a hard disk, an optical disk, a magnetic tape, a PROM, an EPROM, CD-ROM, or DVD-ROM. 
     In a further aspect, the invention provides a method of representing life science knowledge using case frames. The case frames include a first object identifier, a relationship connector, and a second object identifier. The relationship connector is based on a life science ontology. These case frames may be used to represent a wide variety of life science information. 
     The foregoing and other features and advantages of the invention, as well as the invention itself, will be more fully understood from the description, drawings, and claims which follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which: 
         FIG. 1  is a diagrammatic overview of a biological system illustrating the complexity and some of the relationships between the components of the system; 
         FIG. 2  is a schematic illustration of an embodiment of a graph structure according to the present invention for representing life science knowledge; 
         FIGS. 3A-B  are schematic illustrations of an embodiment of a knowledge base according to the present invention, in which multiple datasets are interconnected by relationships to form the knowledge base; 
         FIG. 4  is a schematic illustration of an embodiment of generating nodes and assigning representation descriptors according to the present invention showing using case frames; 
         FIG. 5  is a schematic illustration of a case frame according to an embodiment of the present invention; 
         FIG. 6  is a schematic illustration of a case frame representing an enzymatic reaction according to an embodiment of the invention; 
         FIGS. 7A-G  are schematic illustrations showing various case frames and relations between them according to illustrative embodiments of the invention. 
         FIG. 8  is a flowchart illustrating an embodiment of a method for creating a case frame according to the present invention; 
         FIG. 9  shows an example of a search screen according to an embodiment of the invention; 
         FIG. 10  shows an example of a screen in which a relationship type is selected and information is added to a case frame according to an embodiment of the invention; 
         FIG. 11  shows an example of a screen in which two terms used in a life science ontology are merged according to an embodiment of the invention; 
         FIG. 12  shows a screen illustrating use of a knowledge base to find paths according to an embodiment of the invention; 
         FIG. 13  shows a screen that displays a graphical representation of paths according to an embodiment of the invention; 
         FIG. 14  is a block diagram showing the structure of a life science discovery system according to an embodiment of the present invention; and 
         FIG. 15  is a block diagram showing access restrictions on proprietary portions of a knowledge base according to an embodiment of the invention. 
     
    
    
     DESCRIPTION 
     In accordance with the invention, biological and other Life Sciences knowledge can be represented and manipulated in a computer environment so that the knowledge can be stored and shared. Such Life Sciences knowledge can be reasoned upon by algorithms that are designed to derive new knowledge and make novel conclusions relevant to furthering the understanding of biological systems and underlying mechanisms in Life Sciences. Providing such a knowledge base permits harmonization of numerous types of life science information from numerous sources. 
       FIG. 1  is a diagram showing an example biological system. As can be seen, the system includes various entities, including molecular entities, and numerous relationships between them. To reason about the system shown in  FIG. 1  as a whole requires knowledge of the entire system. A change or problem at any point in the system could have effects throughout the entire system. 
     In accordance with one embodiment of the invention, a system such as that shown in  FIG. 1  may be represented as a graph, such as is shown in  FIG. 2 . The graph shown in  FIG. 2  includes nodes  202  and edges  204 . The nodes  202  represent entities within a biological system, such as compounds, genes, proteins, cells, and tissues. The edges  204  represent relationships between the nodes  202 . 
     In the example shown in  FIG. 2 , various types of nodes are represented by different shapes. For example, a diamond-shaped node, such as the node  206 , represents a cell or tissue. A triangle-shaped node, such as the node  208 , represents a compound. A circle-shaped node, such as the node  210 , represents a gene or protein. Thus, the life science data represented by the nodes may be based on a life science taxonomy, in which each particular entity to be represented by a node in the graph is classified according to its type. 
     The edges in the graph represent various relations between the nodes, as shown in  FIG. 2 . For example, edges may represent a “binds to” relation  212 , an “is expressed in” relation  214 , an “are co-regulated based on expression profiling” relation  216 , an “inhibits” relation  218 , a “co-occur in a manuscript” relation  220 , or a “share structural element” relation  222 . These types of relationships between the nodes may be referred to as “representation descriptors.” Generally, a representation descriptor describes a relationship between a pair of nodes. These relationships may be referred to as epistemological relationships between nodes, since they represent knowledge about the relation of one entity to another. 
     In accordance with an embodiment of the invention, the nodes in the graph may also represent relationships between nodes. Thus, it is possible to represent relationships between relationships, or relationships between a relationship and another type of life science entity represented in the graph. For example a relationship between two nodes that represent chemicals may represent a reaction. This reaction may be a node in a relationship between the reaction and a chemical that inhibits the reaction. 
     In accordance with an embodiment of the invention, the entities and relationships (i.e., the nodes and edges) that make up a graph, such as the graph shown in  FIG. 2 , may be stored as a web of interrelated nodes in a knowledge base. Various algorithms may be applied to such graphs to provide automated reasoning capabilities, for knowledge assembly and mining. 
     The knowledge represented within the life science knowledge base may be of various different types, drawn from various different sources. For example,  FIG. 3A  shows three separate sets of data, representing different types of life sciences information. A dataset  302  is a genomic database, including information on genes, and relations between them. For example, a node  304  may represent an oncogene, while a node  306  represents a gene that inhibits the gene represented by the node  304 . 
     A dataset  308  represents proteins, and relations between them. Thus, a node  310  in dataset  308  may represent a particular protein. Similarly, a dataset  312  represents diseases and their interrelations, and nodes in dataset  308  may represent various disease states. 
     Each of the datasets  302 ,  308 , and  312  could be a knowledge base in its own right, as each contains a representation of knowledge on a particular topic of relevance to the life sciences. However, as shown in  FIG. 3A , a greater knowledge base may be formed by creating connections between the datasets  302 ,  308 , and  312 , based on knowledge of the relations between genes, proteins, and diseases. 
     For example, relations, such as a relation  316 , may represent the knowledge that a particular gene codes for or produces a particular protein. A lack or abundance of a particular protein or set of proteins may be associated with particular diseases. For example, a relation  320  may indicate that an abundance of the protein represented by the node  310  in the protein dataset  308  causes the disease (e.g., cancer) represented by the node  322  in the disease dataset  312 . 
     Relations can be created between any members of any datasets. For example, a gene represented by the node  306  in the gene dataset  302  may be directly linked to a disease state represented by a node  318  in the disease dataset  312  by a relation  324 . 
     As can be seen in  FIG. 3B , there are many different types of life science data that can be combined in a knowledge base. Knowledge base  350  includes a web of relations between nodes representing knowledge in a gene dataset  352 , an MRNA dataset  354 , a protein dataset  356 , a cell dataset  358 , a tissue dataset  360 , an organ dataset  362 , a medical dataset  364 , an epidemiology dataset  366 , a chemistry dataset  368 , a toxicology dataset  370 , and a patient dataset  372 . All of these datasets contain nodes that represent life science information, and the nodes in each of the datasets may be related to nodes in the same dataset, or in other datasets. 
     Knowledge base  350  contains a wide variety of life science information, across many fields. The information in knowledge base  350  ranges from genetic information, in gene dataset  352 , to medical information, in medical dataset  364 , to information on individual patients in patient dataset  372 , and on entire populations, in epidemiology dataset  366 . 
     In addition to the various datasets that are shown in  FIG. 3B , there may be many other datasets, or types of life science information that may be included in a knowledge base in accordance with an embodiment of the invention. For example, a knowledge base could further include medical record data, structure/activity relationship data, information on infectious pathology, information on clinical trials, and any other type of life science information. By interconnecting information of numerous types and from a variety of fields, as shown in  FIG. 3B , a knowledge base according to an embodiment of the invention may harmonize and combine many types of life science information, and provide researchers with the ability to find and understand the many relationships between life science information. 
     In one embodiment, the nodes and representation descriptors that represent life sciences information are built up in a knowledge base using case frames. A case frame provides a representational formalism for life sciences knowledge and data. As will be more fully described below, each case frame corresponse to a specific concept in the life sciences and consists of two or more nodes indicative of life science data, with one or more relationship descriptors between and among the nodes. 
     These case frames may be made available in a library, from which they may be selected and instantiated to form a knowledge base. The case frames in the library can be viewed as templates, because specific information has not been specified for each node and relationship. During instantiation, these “blanks”: are filled in, to form an instance of the case frame in a knowledge base. As case frames are instantiated, those that share common nodes and/or relationships may be clustered to form a network of connected case frames. 
     Alternatively, nodes and relationships can be built up and represented in a relational database, an object-oriented environment, a logic-based environment, or in other database or programming paradigms. 
     Referring to  FIG. 4 , construction of case frames from life sciences information is illustrated. In this example, a reaction  406 , shown in a portion  404  of a metabolic pathway  402  is to be added to the knowledge base. Reaction  406  is an enzymatic reaction in which a substrate  408  (in this case, β-D-Fructose-6P) is transformed into a product  410  (in this case, α-D-Glucose-6P) through the action of an enzyme  412 . 
     A case frame  414  is used to represent the information. In this instance, the case frame  414  represents the substrate  408  being transformed to the product  410  through a reaction involving enzyme  412 . The information may then be transformed into a computer-readable representation  416 , for storage in a knowledge base, and manipulation by automated reasoning algorithms. 
     Knowledge from the metabolic pathway  402  may be placed in a knowledge base using numerous case frames, such as case frame  406 . 
     Referring to  FIG. 5 , a general example of a case frame for representing particular life sciences knowledge is described. The case frame  502  of  FIG. 5  includes an entry A  504  and an entry B  506 . The entries A  504  and B  506  are related by a relation R  508 . Each of the entries A  504  and B  506  represent objects of relevance in the life sciences, such as proteins, enzymes, genes, cells, tissues, compounds, molecules, or other life science-related objects. 
     Each of the entries A  504 , B  506 , and the relation R  508  may be associated with various attributes, and may be connected to entries or relations (not shown). Using a collection of case frames, such as case frame  502 , large networks of life science knowledge may be built. 
       FIG. 6  shows an instance of a case frame  602 , which is somewhat more complex than the case frame  502  of  FIG. 5 . The central relation R  604  of the case frame  602  represents an enzymatic reaction. The enzymatic reaction shown in the case frame  602  has reactants Pyruvate  606  and CoA  608 , and produces Acetyl-CoA  610 . The enzymatic reaction has a coenzyme cofactor  612 , is catalyzed by an enzyme  614 , and is inhibited by a protein X  616  (the arrow for inhibition is shown in  FIG. 6  as being different than the other arrows). 
     The case frame  602  can be converted into a pseudocode form. For example, known languages, such as XML or Java may be used to represent a case frame, such as the case frame  602 . Although the syntax of the pseudocode may vary, the types of objects, attributes, and relations will be the same. An example of pseudocode representing the case frame  602  is: 
     Create Relation Called R1 
     R1 has reaction CoA 
     R1 has reactant Pyruvate 
     R1 is catalyzed_by Enzyme 
     R1 has product Acetyl-CoA 
     R1 is—a enzymatic reaction 
     R1 has_coenzyme cofactor 
     Protein X inhibits R1 
     Generic forms of case frames may be produced. For example, a generic or empty case frame for an enzymatic reaction could be represented as: 
     Create Relation Called (R1) 
     R1 has reactant  ——————   
     R1 has reactant  ——————   
     . . . (repeat for all substrates) 
     R1 is catalyzed_by  ——————   
     R1 is catalyzed_by  ——————   
     . . . (repeat for all catalysts) 
     R1 has product  ——————   
     R1 has product  ——————   
     . . . (repeat for all products) 
     R1 is—a enzymatic reaction 
     R1 has_coenzyme  ——————   
     R1 has_coenzyme  ——————   
     . . . (repeat for all cofactors) 
     R1 occurs in tissue  —————— (repeat for all tissues) 
     R1 occurs in compartment  13 ————— (repeat for all subcellular compartments) 
     R1 occurs in species  —————— (repeat for all species) 
     R1 is inhibited by  —————— (repeat for all) 
     This empty or generic case frame may be used to represent any enzymatic reaction in any known organism or tissue. This type of representation of a case frame permits any aspect of a reaction to be represented. Additionally, other aspects may be added, such as energy levels, species data and other supporting data as it becomes available. 
     A library of such empty or generic case frames can be built to represent substantially all of the known atomic concepts in life sciences. By creating such a library of empty case frames, complex concepts in life sciences can be represented by filling in the blanks in the appropriate set of case frames from the library of generic or empty case frames. 
     The empty or generic case frame shown above represents an enzymatic reaction. This same case frame can be generalized to show various reactions, such as a protein binding or an activation of transcription. The statement in the example shown above that says that relation R1 is a enzymatic reaction can be replaced by one of many terms such as: 
     R1 is—a protein_binding relation 
     R1 is—a activation realtion 
     R1 is—a inhibition relation 
     R1 is—a auto-phosphyrylation relation 
     R1 is—a comentioned-in-the-literature relation 
     R1 is—a has-related-patent relation 
     Generally, case frames can be built using terms that represent objects, classes of objects, events, or classes of events. Some of these terms represent relationships between terms, such as one term being a subset of another. In one embodiment, case frames are based on terms that specify individuals (i.e., individual objects or events), classes (i.e., classes of individuals), relationships (i.e., relationships between other terms), and metaclasses (i.e., classes of classes). 
     Examples of classes include types of life science objects, such as chemicals, organisms, reactions, processes, etc., as well as types of objects that are used for bookkeeping or other uses, such as databases and documents. Similarly, relations may include life science relations, such as “catalyzed by”, “activates”, and “inhibits”, as well as other types of relations, such as “keggMapID”, which is a relation used to specify that an object is referenced with a specific ID in the KEGG database, or “subset of”, which specifies that one term is a subset of another. An examples of a metaclass is “species”, in which instances are classes of organism which are designated as species in a standard classification scheme, and “basic term type.” 
       FIG. 7A  shows relationships between classes of case frames that are used in one embodiment of the present invention for representing chemicals. The arrows in the diagram represent a “subset of” relationship. Thus, for example, an enzyme class  702  is a subset of a chemical class  700 , and an RNA class  706  is a subset of a Nucleic Acid class  704 . 
     The structure of the subset relations shown in  FIG. 7A  is useful for facilitating reasoning about the various classes of chemical. In this example, a “chemical” is defined as any chemical entity, from macromolecules to hydrogen ions. A “molecule” (i.e., molecule class  708  is defined as a chemical in which the atoms are primarily covalently linked. The enzyme class  702  is a subset of the chemical class  700 , rather than a protein class  710  or the molecule class  708 , since enzymatic reactions may be catalyzed by ribozymes or molecular complexes. 
     Case frames are also used for representing interactions. In one embodiment, such interactions are a class (which is a subset of a “physical process” class) of events where chemicals and/or cellular components affect each other. Examples of such interactions include a reaction class, a binding class, a gene expression class, and increase class, a decrease class, a translocation class, an activation class, and an inhibition class. 
       FIG. 7B  shows an example instance of an enzymatic reaction, which is a subset of a reaction. As can be seen, an enzymatic reaction  720  is characterized by assertions using various relationships. An “X catalyzedBy Y” relationship  722  represents a relationship in which reactions of type X (in this instance, Reaction R02347) are catalyzed by enzyme molecules of type Y (in this instance, Estradiol 17 alpha-dehydrogenase). similarly, an “X reactant Y” relationship, such as relationships  724  and  726 , represents that reactions of type X consume chemicals of type Y. An “X product Y” relationship, such as relationships  727  and  728 , which represents that reactions of type X produce chemicals of type Y. 
     In addition to the relations shown in  FIG. 7B , a case frame representing an enzymatic reaction my include other relationships. For example, an “X cofactor Y” relationship (not shown) may be used to represent that the chemical with the name Y binds to the enzyme as a necessary cofactor in reactions of type X. Note that this implies that an “X reactant Y” relationship. An “X effector Y” relationship (not shown) may be used to represent that interactions of type X are effected by chemicals whose name is Y. An “X inhibitingChemical Y” relationship (not shown) represents that interactions of type X are inhibited by chemicals whose name is Y. 
     In one embodiment, some classes of EnzymaticReaction correspond exactly to a particular EC number. These classes are instances of the metaclass “ECClass,” and represent classes of reaction that cross species boundaries, and have been grouped by EC on the basis of function. 
     Case frames are used in some embodiments of the invention to represent genes, proteins, and RNA, and relationships between them. For example, structural protein relationships may be represented by an “X hasProteinBindingDomain Y” that indicates that proteins of type X have a protein domain of type Y. Functional protein relationships may also be represented. 
       FIG. 7C  shows an example case frame for representing gene expression. In the example shown in  FIG. 7C , gene expression for the human p53 gene is shown. An “expressesGene” relationship  730  indicates that the TP53 gene expression  731  expresses the TP53 gene  733 . a “geneProduct” relationship  732  indicates that the TP53 protein  735  is produced by the TP53 gene expression  731 . A “hasRNATranscript” relationship  734  indicates that TP53 RNA  736  is the RNA transcript of the TP53 gene expression  731 . The TP53 gene  733  has an “is TranscribedToRNA” relationship with the TP53 RNA  736 , which has an “is TranslatedToProtein” relationship with the TP53 protein  735 . 
     Generally, a GeneExpression is characterized by assertions using the following relationships: 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 X expressesGene Y 
                 X is a type of GeneExpression that 
               
               
                   
                 expresses Gene Y 
               
               
                 X geneProduct Y 
                 a Chemical Y is produced by a GeneExpression 
               
               
                   
                 of type X 
               
               
                 X upregulatedBy Y 
                 GeneExpressions of type X are upregulated by 
               
               
                   
                 things of type Y 
               
               
                 X downregulatedBy Y 
                 GeneExpressions of type X are downregulated 
               
               
                   
                 by things of type Y 
               
               
                 X regulatedBy Y 
                 GeneExpressions of type X are affected by 
               
               
                   
                 things of type Y 
               
               
                   
               
             
          
         
       
     
     Additionally, genes, proteins, and RNA may be further characterized by the following relationships in a case frame: 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 X translatesRNA Y 
                 RNA of type Y is translated as 
               
               
                   
                 part of GeneExpression of type X 
               
               
                 X homologousGene Y 
                 Gene X is homologous to gene Y 
               
               
                 X isTranscribedToRNA Y 
                 There exists gene expression such that 
               
               
                   
                 gene X is transcribed to RNA Y 
               
               
                 X isTranslatedToProtein Y 
                 There exists gene expression such 
               
               
                   
                 that RNA X is translated to Protein Y 
               
               
                 X transcriptionModulationSite Y 
                 Y is a binding site that affects the 
               
               
                   
                 transcription of gene X 
               
               
                 X cytogeneticPosition Y 
                 Y is the location of gene X within its 
               
               
                   
                 chromosome 
               
               
                 X onChromosomeNumber Y 
                 The species-specific number of the 
               
               
                   
                 chromosome on which a gene is located 
               
               
                 X syntheticallyLethalWith Y 
                 Either gene X or gene Y is sufficient 
               
               
                   
                 for the organism to survive, but at least  
               
               
                   
                 one is required 
               
               
                   
               
             
          
         
       
     
     Referring to  FIG. 7D , the relationship between various case frames that are used in some embodiments of the invention to represent binding is shown. A “NucleicAcid Binding” class  752  is a subset of a general “binding” class  750 . A “DNA Binding” class  754  and an “RNA Binding” class  756  are subsets of the “NucleicAcid Binding” class  752 . A “DNA-Transcription Factor Binding” class  757  is a subset of the “DNA Binding” class  754 , and an “RNA-Transcription Factor Binding” class  758  is a subset of the “RNA Binding” class  756 . In some embodiments, certain of the classes that define bindings correspond to GO terms. 
     Additional classes related to binding include an “Unbinding” class (not shown), and a “MolecularComplex” class (not shown). A “MolecularComplex” is a class of chemical characterized by assertions that use an “X complexComponent Y” relationship, which represents that complexes of type X include molecules or molecular complexes of type Y. 
     A binding interaction is a class of process that is characterized by assertions using the following relationships: 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 X bindingInput Y 
                 Bindings of type X involve molecules or 
               
               
                   
                   
                 molecular complexes of type Y 
               
               
                   
                 X bindingOutput Z 
                 Bindings of type X produce complexes of 
               
               
                   
                   
                 type Z 
               
               
                   
                   
               
             
          
         
       
     
     An example of the use of such relations is shown in  FIG. 7E , in which “bindingInput” relationships  760  and  761 , and a “bindingOutput” relationship  762  are used to specify the inputs and output of a binding process. Other relationships, such as “subsetOf” relationships  764  and  766  are used to specify that the binding process is a subset of a DNA-transcription factor binding (relationship  764 ), and that the output of the binding is a subset of a molecular complex (relationship  766 ). 
     In some embodiments, molecular complexes are represented by a class of chemical characterized by assertions using a “complexComponent” relationship. The “X complexComponent Y” relationship indicates that complexes of type X include molecules or molecular complexes of type Y. In some embodiments, the “complexComponent” relationship may include a numeric literal that specifies the number of molecules or molexular complexes of a given class. Thus, a “X complexComponent Y N” relationship specifies that complexes of type X include N molecules or molecular complexes of type Y. This type of relationships can be used to represent homodimers, homotrimers, homotetramers, etc. 
     In some embodiments, case frames are used to represent modifications of polymers. For linear polymers, such case frames are characterized by a relationships or assertions that indicate the type and position of the modification. Included in such modifications of polymers are case frames for representing post-translational modifications of proteins. This may include case frames that represent phosphorylation, acetylation, peptide-bond cleavage, glycosylayion, lipidation (including fatty-acylation and prenylation), methylation, metallation, cross-linking, hydroxylation, sulfation ADP-ribosylation, and covalent attachment of prosthetic groups such as flavin and heme. This may be accomplished by relationships specific to each type of modification, such as the following: 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 X phosphorylatedAt N 
                 Proteins of type X are phosphorylated at 
               
               
                   
                 position N 
               
               
                 X acetylatedAt N 
                 Polymers of type X are acetylated at 
               
               
                   
                 position N 
               
               
                 X ribosylatedAt N 
                 Polymers of type X are ribosylated at 
               
               
                   
                 position N 
               
               
                 X cleavedAt N 
                 Polymers of type X are the remainder after 
               
               
                   
                 cleavage at position N 
               
               
                 X glycosylatedAt N 
                 Polymers of type X are glycosylated at 
               
               
                   
                 position N 
               
               
                 X methylatedAt N 
                 Polymers of type X are methylated at 
               
               
                   
                 position N 
               
               
                 X lipidatedAt N 
                 Polymers of type X are lipidated at 
               
               
                   
                 position N 
               
               
                 X fattyAcylatedAt N 
                 Polymers of type X are fatty-acylated at 
               
               
                   
                 position N 
               
               
                 X metallationAt N 
                 Polymers of type X are metallated at 
               
               
                   
                 position N 
               
               
                 X hydroxylatedAt N 
                 Polymers of type X are hydroxylated at 
               
               
                   
                 position N 
               
               
                 X sulfatedAt N 
                 Polymers of type X are sulfated at position N 
               
               
                   
               
             
          
         
       
     
       FIG. 7F  shows an example of a phosphorylation reaction  771 , which may be represented as an enzymatic reaction in which the reactant  770  is a protein, and the product  772  is a modified subclass of protein. The kinase  774  that performs the phosphorylation is the catalyst for the reaction. The “phosphorylatedAt” relationship  775  is used to indicate the position at which the product  772  is phosphorylated. Other post-translational modifications may be handled in the same manner as phosphorylations. 
     In some embodiments, if there are multiple kinases that may produce the same phosphorylation, each reaction is represented as a separate class of process, all of which share a common product. This feature of the representation permits the product to be used in other relationships, such as inhibations and activations, rather than starting a separate relationship for each reaction that produces the product. 
     The removal of modifications, such as deacetylations, may be represented as negated assertions on the products. In such cases, the modified product class is the subset of polymer that is explicitly known to not be modified at a given position. 
     In some embodiments, case frames are used to represent causal relationships, such as activation and inhibition, also referred to as “increase” and “decrease” or “upregulated” or “downregulated”. Activation and inhibition are subsets of modulation, which is a subset of a process class. Generally, activation and inhibition connect a cause—the “inhibitor” or “activator”—with a process that is affected by the activation or inhibition. They can also connect a cause with a biological entity, indicating that the cause modulates the abundance of the entity. Note that since activation and inhibition are a subset of process, it is possible to represent an activation or inhibition being activated or inhibited. 
     Direct activation and indirect Inhibition are subsets of activation and inhibition, respectively. They indicate that instances of a class directly affect instances of a process. Regular activation and inhibition do not necessarily imply such an immediate causal relationship. The cause of a regular activation or inhibition may be many steps removed, or may not be known. 
     In some embodiments, Activations are connected to other classes by the relationships “activates” and “activator”. The “X activates Y” relationship indicates that things of type Y are activated by activations of type X. The “X activator Y” relationship indicates that activations of type X are caused by things of type Y. 
     Similarly, inhibitions are connected to other classes by the relationships “inhibits” and “inhibitor”. The “X inhibits Y” relationship indicates that things of type Y are inhibited in inhibitions of type X. The “X inhibitor Y” relationship indicates that inhibitions of type X are caused by things of type Y. 
     In some embodiments, case frames are used to represent competition between processes. An “X competeswith Y” relationship indicates that processes of type X compete with processes of type Y. While such competition can frequently be inferred, the “competeswith” relationship permits it to be explicitly stated as a case frame. 
     In some embodiments, case frames are used to represent the requirements of processes. An “X requires Y” relationship indicates that processes of type X require the presence of objects or processes of type Y. Note that although a “requires” relationship indicates a dependency, the nature of the dependency is not known. The “requires” relationship does not imply that increases in the required objects or processes will increase the process, but does imply that decreases in the required objects or processes will decrease the process. 
     In some embodiments, case frames are used to represent translocations. Such translocations are processes that represent change in location for classes of objects. The relationships for a translocation indicate the type of object and type of locations. 
     Translocations may be directional translocations, in which the objects are transported from one type of location to another type, but not the reverse. There are also translocations that connect two locations, indicating that the objects may move in both directions. This is a common case where molecules able to pass a barrier, such as a membrane, are in equilibrium across the barrier, such that a net flow of molecules is due to their creation, destruction, or other removal on one side of the barrier. 
     The relationships that characterize a translocatin are listed in the following table: 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 X tranlocates Y 
                 Things of type Y change location in 
               
               
                   
                 translocations of type X. 
               
               
                 X translocatedFrom Y 
                 In translocations of type X, the objects that 
               
               
                   
                 change location are initially at locations of 
               
               
                   
                 type Y. 
               
               
                 X translocatedTo Y 
                 In translocations of type X, the objects that 
               
               
                   
                 change location move to locations of type Y. 
               
               
                 X translocatedBy Y 
                 In translocations of type X the 
               
               
                   
                 translocation is accomplished or affected 
               
               
                   
                 by the biological entity or process Y 
               
               
                   
               
             
          
         
       
     
     The following table provides a list of case frames, including classes, metaclasses, and relationships, that are used to represent life-sciences information related to molecular biology: 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 C1 subsetOf C2 
                 C1 subsetOf C2: C2 is a class which is a 
               
               
                   
                 superset of the class C1 
               
               
                 X instanceOf C 
                 X instanceOf C: X is a member of class C 
               
               
                 MetaClass; TaxonomicClass 
                 Instances are Classes which form the standard 
               
               
                   
                 classification scheme for organisms 
               
               
                 MetaClass: Species 
                 “Instances are Classes of Organism which are 
               
               
                   
                 designated as Species in the standard 
               
               
                   
                 classification scheme 
               
               
                 MetaClass: OrganismStrain 
                 Instances are Classes of Organism which are 
               
               
                   
                 genetically distinguished and which are more 
               
               
                   
                 specific than Species 
               
               
                 MetaClass: OrganismAnamorph 
                 Instances are Classes of Organism which 
               
               
                   
                 distinct morphological forms of a species, such 
               
               
                   
                 as an asexual form of a Fungal species. Should 
               
               
                   
                 be a subset of a species and has the same 
               
               
                   
                 genome as the species. 
               
               
                 Class: PhysicalObject 
                 Physically existing individual object 
               
               
                 Class: Chemical 
                 Any chemical entity, from macromolecules to 
               
               
                   
                 hydrogen ions. 
               
               
                 Class: Molecule 
                 Instances are chemicals in which the atoms are 
               
               
                   
                 primarily covalently linked 
               
               
                 Class: Polymer Extent 
                 A linear polymeric molecule or a sub-region of 
               
               
                   
                 a linear polymeric molecule. The sequence of 
               
               
                   
                 units of the extent may or may not be known 
               
               
                 Class: NucleicAcid Extent 
                 NucleicAcid molecule or a sub-region of a 
               
               
                   
                 NucleicAcid molecule, such as a binding site 
               
               
                   
                 or gene. The sequence of the extent may or 
               
               
                   
                 may not be known 
               
               
                 Class: NucleicAcid 
               
               
                 Class: Artificial NucleicAcid Sequence 
                 An artificially created NucleicAcid molecule 
               
               
                   
                 with a specified sequence 
               
               
                 Class: DNA Extent 
                 DNA molecule or a sub-region of a DNA 
               
               
                   
                 molecule, such as a binding site or gene. The 
               
               
                   
                 sequence of the extent may or may not be 
               
               
                   
                 known 
               
               
                 Class: DNA 
                 DNA molecule or a subsequence of a DNA 
               
               
                   
                 molecule - i.e. a binding site is also DNA 
               
               
                 Class: RNA Extent 
                 RNA molecule or a sub-region of a RNA 
               
               
                   
                 molecule, such as a binding site or gene. The 
               
               
                   
                 sequence of the extent may or may not be 
               
               
                   
                 known 
               
               
                 Class: RNA 
                 RNA molecule or a subsequence of an RNA 
               
               
                   
                 molecule 
               
               
                 Class: NucleicAcid BindingSite 
                 Sequence of NucleicAcid identified by its 
               
               
                   
                 ability to participate in a binding interaction 
               
               
                   
                 with a molecule or molecular complex 
               
               
                 Class: DNA BindingSite 
                 Sequence of DNA identified by its ability to 
               
               
                   
                 participate in a binding interaction with a 
               
               
                   
                 molecule or molecular complex 
               
               
                 Class: RNA BindingSite 
                 Sequence of RNA identified by its ability to 
               
               
                   
                 participate in a binding interaction with a 
               
               
                   
                 molecule or molecular complex 
               
               
                 Class: DNA PromoterSite 
                 DNA BindingSite which acts as a promoter for 
               
               
                   
                 the Gene when it is bound 
               
               
                 Class; DNA EnhancerSite 
                 DNA BindingSite which acts as an enhancer 
               
               
                   
                 for the Gene when it is bound 
               
               
                 Class: SmallMolecule 
                 Molecules typically smaller than proteins and 
               
               
                   
                 other macromolecules” 
               
               
                 Class: Protein Extent 
                 Protein molecule or a sub-region of a Protein 
               
               
                   
                 molecule, such as a Protein Domain. The 
               
               
                   
                 sequence of the extent may or may not be 
               
               
                   
                 known 
               
               
                 Class: Protein 
                 A polypeptide sequence 
               
               
                 Class: ProteinDomain 
                 A region of a protein. Typically a region which 
               
               
                   
                 has biologically significant binding activity 
               
               
                 Class: Enzyme 
                 A Chemical which catalyzes specific reactions. 
               
               
                 Class: Gene 
                 A portion of DNA (or in some cases RNA) 
               
               
                   
                 which can be expressed into gene products by 
               
               
                   
                 an Organism 
               
               
                 Class: Process 
                 Events or Processes” 
               
               
                 Class: PhysicalProcess 
                 Processes or Events involving physical objects 
               
               
                   
                 and actions 
               
               
                 Class: Organism 
                 Organism 
               
               
                 Class: Virus 
                 Viruses 
               
               
                 Class: CellularOrganism 
                 cellular organisms 
               
               
                 MetaClass: ECClass 
                 Instances are Classes which form the standard 
               
               
                   
                 classification scheme for enzymatic reactions 
               
               
                 MetaClass: ProteinFamilyLevel 
                 Instances are Classes related to gene 
               
               
                   
                 expression and protein function at the level of 
               
               
                   
                 families of protein function and structure. 
               
               
                 MetaClass: LocusLevel 
                 Instances are Classes related to gene 
               
               
                   
                 expression and protein function at the species- 
               
               
                   
                 specific Chromosome Location level. More 
               
               
                   
                 general than SpliceVariantLevel, more specific 
               
               
                   
                 than ProteinFamilyLevel 
               
               
                 MetaClass: SpliceVariantLevel 
                 Instances are Classes related to gene 
               
               
                   
                 expression and protein function at the level of 
               
               
                   
                 specific splice variants 
               
               
                 X keggMapID Y 
                 the object X is referenced on the map with the 
               
               
                   
                 ID Y in the KEGG database 
               
               
                 X ecNumber Y 
                 enzymes or enzymatic reactions of type X are 
               
               
                   
                 assigned the designation Y by the Enzyme 
               
               
                   
                 Commission database 
               
               
                 X genbankAC Y 
                 the Genbank Database refers X to by the 
               
               
                   
                 accession number Y 
               
               
                 X genbankID Y 
                 X is referred to by the id Y by the Genbank 
               
               
                   
                 Database” 
               
               
                 X unigeneAC Y 
                 X is referred to by the accession number Y in 
               
               
                   
                 the UniGene Database 
               
               
                   
                 unigeneAC term2InstanceOf 
               
               
                   
                 StringLiteral Value 
               
               
                 X locuslinkID Y 
                 the ID Y in the LocusLink Database refers to X 
               
               
                 X locuslinkName Y 
                 X is referred to by the name Y in the 
               
               
                   
                 LocusLink Database 
               
               
                 X refseqID Y 
                 the ID Y in the RefSeq Database refers to X 
               
               
                 X pfamID Y 
                 the ID Y in the PFAM Database refers to X 
               
               
                 X omimID Y 
                 X is referenced in an article with ID Y in the 
               
               
                   
                 OMIM Database 
               
               
                 X prositeID Y 
                 the ID Y in the Prosite Database refers to X 
               
               
                 X smartID Y 
                 the ID Y in the Smart Database refers to X 
               
               
                 X casID Y 
                 chemical type X is referred to by the ID Y in 
               
               
                   
                 the CAS Database 
               
               
                 X keggCompoundID Y 
                 chemical type X is referred to by the ID Y in 
               
               
                   
                 the KEGG Database 
               
               
                 X keggReactionDoc Y 
                 reaction type X is documented by the string Y 
               
               
                   
                 in the KEGG Database 
               
               
                 X keggReactionID Y 
                 reaction type X is referred to by the ID Y in the 
               
               
                   
                 KEGG Database 
               
               
                 X keggOrganismID Y 
                 organism type X is referred to by the ID Y in 
               
               
                   
                 the KEGG Database 
               
               
                 transfacAC 
                 Accession number in the Transfac database 
               
               
                 transfacID 
                 ID string in the Transfac database 
               
               
                 pirID 
                 ID string in the PIR database 
               
               
                 pirAC 
                 Accession number in the PIR database 
               
               
                 swissProtID 
                 ID string in the SwissProt database 
               
               
                 swissProtAC 
                 Accession number in the SwissProt database 
               
               
                 pubmedID 
                 ID string in the Entrez PubMed database 
               
               
                 emblID 
                 ID string in the EMBL database 
               
               
                 transfacOrganismName 
                 organism name used in Transfac database (only 
               
               
                   
                 recorded when different from NCBI name) 
               
               
                 X geneName Y 
                 Gene X has the official name Y 
               
               
                 X geneSymbol Y 
                 Gene X has the official symbol Y 
               
               
                 X aliasGeneSymbol Y 
                 Gene X is also known by symbol Y 
               
               
                 X goAnnotation Y 
                 things of type X are annotated with the Gene 
               
               
                   
                 Ontology (GO) Database term Y 
               
               
                 Class: Interaction 
                 General class of events or processes Chemicals 
               
               
                   
                 and/or cellular components affect each other 
               
               
                 Class: Reaction 
                 Chemical Reactions 
               
               
                 Class: EnzymaticReaction 
                 Reactions catalyzed by Enzymes 
               
               
                 Class: Binding 
               
               
                 Class: Unbinding 
               
               
                 Class: NucleicAcidBinding 
               
               
                 Class: DNA Binding 
               
               
                 Class: DNA-TranscriptionFactor Binding 
                 Binding in which a transcription factor binds to 
               
               
                   
                 a segment of DNA 
               
               
                   
                 RNA Binding 
               
               
                 Class: RNA-TranscriptionFactor Binding 
                 Binding in which a transcription factor binds to 
               
               
                   
                 a segment of RNA 
               
               
                 Class: GeneExpression 
               
               
                 X catalyzedBy Y 
                 reactions of type X are catalyzed by enzyme 
               
               
                   
                 molecules of type Y 
               
               
                 X reactant Y 
                 reactions of type X consume chemicals of type Y 
               
               
                 X product Y 
                 reactions of type X produce chemicals of type Y 
               
               
                 X cofactor Y 
                 the chemical with the name Y binds to the 
               
               
                   
                 enzyme as a necessary cofactor in reactions of 
               
               
                   
                 type X. It should imply X reactant Y. 
               
               
                 X effector Y 
                 Interactions of type X are effected by 
               
               
                   
                 Chemicals whose name is Y. 
               
               
                 X inhibitingChemical Y 
                 Interactions of type X are inhibited by 
               
               
                   
                 Chemicals whose name is Y. 
               
               
                 X chemicalFormula Y 
                 chemical type X has the formula Y” 
               
               
                 X hasProteinBindingDomain Y 
                 proteins of type X have a ProteinDomain of 
               
               
                   
                 type Y” 
               
               
                 X expressesGene Y 
                 X is a type of GeneExpression that expresses 
               
               
                   
                 Gene Y 
               
               
                 X geneProduct Y 
                 indicates that Chemical Y is produced by 
               
               
                   
                 GeneExpression of type X 
               
               
                 X upregulatedBy Y 
                 GeneExpressions of type X are upregulated by 
               
               
                   
                 Things of type Y 
               
               
                 X downregulatedBy Y 
                 GeneExpressions of type X are downregulated 
               
               
                   
                 by Things of type Y 
               
               
                 X regulatedBy Y 
                 GeneExpressions of type X are affected by 
               
               
                   
                 Things of type Y 
               
               
                 X translatesRNA Y 
                 RNA of type Y is translated as part of 
               
               
                   
                 GeneExpression of type X 
               
               
                 X homologousGene Y 
                 Gene X is homologous to Gene Y 
               
               
                 X isTranscribedToRNA Y 
                 there exists gene expression such that Gene X 
               
               
                   
                 is transcribed to RNA Y 
               
               
                 X isTranslatedToProtein Y 
                 there exists gene expression such that RNA X 
               
               
                   
                 is translated to Protein Y” 
               
               
                 X transcriptionModulationSite Y 
                 Y is a binding site that affects the transcription 
               
               
                   
                 of Gene X 
               
               
                 X cytogeneticPosition Y 
                 Y is the location of gene X within its 
               
               
                   
                 chromosome 
               
               
                 X onChromosomeNumber Y 
                 the number of the chromosome on which a 
               
               
                   
                 gene is located. Only makes sense if the gene 
               
               
                   
                 is species-specific 
               
               
                 X syntheticallyLethalWith Y 
                 either Gene X or Gene Y is sufficient for the 
               
               
                   
                 organism to survive, but at least one is 
               
               
                   
                 required. 
               
               
                 X location Y 
                 things of type Y may be found at, on, or in 
               
               
                   
                 physical objects of type X 
               
               
                 X bindingInput Y 
                 bindings of type X involve molecules or 
               
               
                   
                 molecular complexes of type Y 
               
               
                 X bindingOutput Z 
                 bindings of type X produce complexes of type Z 
               
               
                 Class: MolecularComplex subsetOf Chemical 
               
               
                 X complexComponent Y 
                 complexes of type X include molecules or 
               
               
                   
                 molecular complexes of type Y 
               
               
                 X complexComponent Y N 
                 complexes of type X include N molecules or 
               
               
                   
                 molecular complexes of type Y 
               
               
                 X phosphorylatedAt N 
                 Polymers of type X are phosphorylated at 
               
               
                   
                 position N 
               
               
                 X acetylatedAt N 
                 Polymers of type X are acetylated at position N 
               
               
                 X ribosylatedAt N 
                 Polymers of type X are ribosylated at position N 
               
               
                 X cleavedAt N 
                 Polymers of type X are the remainder after 
               
               
                   
                 cleavage at position N 
               
               
                 X glycosylatedAt N 
                 Polymers of type X are glycosylated at 
               
               
                   
                 position N 
               
               
                 X methylatedAt N 
                 Proteins of type X are methylated at position N 
               
               
                 X lipidatedAt N 
                 Proteins of type X are lipidated at position N 
               
               
                 X fattyAcylatedAt N 
                 Proteins of type X are fattyAcylated at position N 
               
               
                 X metallationAt N 
                 Proteins of type X are metallated at position N 
               
               
                 X hydroxylatedAt N 
                 Proteins of type X are hydroxylated at position N 
               
               
                 X sulfatedAt N 
                 Proteins of type X are sulfated at position N 
               
               
                 Class: ProteinDegradation subsetOf 
               
               
                 EnzymaticReaction 
               
               
                 Class: ProteinDegradation subsetOf 
               
               
                 EnzymaticReaction 
               
               
                 Class: Modulation subsetOf Process 
               
               
                 Class: Activation subsetOf Modulation 
               
               
                 Class: Inhibition subsetOf Modulation 
               
               
                 Class: DirectActivation subsetOf Activation 
               
               
                 Class: DirectInhibition subsetOf Inhibition 
               
               
                 X activates Y 
                 Things of type Y are activated by Activations 
               
               
                   
                 of type X 
               
               
                 X activator Y 
                 Activations of type X are caused by Things of 
               
               
                   
                 Type Y 
               
               
                 X inhibits Y 
                 Things of type Y are inhibited in Inhibitions of 
               
               
                   
                 type X 
               
               
                 X inhibitor Y 
                 Inhibitions of type X are caused by Things of 
               
               
                   
                 Type Y 
               
               
                 X competesWith Y 
                 Processes of type X compete with Processes of 
               
               
                   
                 type Y 
               
               
                 X requires Y 
                 Processes of type X require the presence of 
               
               
                   
                 objects or processes of type Y. 
               
               
                 Translocation subsetOf Process 
               
               
                 X translocatedObject Y 
                 Things of type Y change location in 
               
               
                   
                 Translocations of type X 
               
               
                 X fromLocation Y 
                 In Translocations of type X, the objects that 
               
               
                   
                 change location are initially at locations of type Y. 
               
               
                 X toLocation Y 
                 In Translocations of type X, the objects that 
               
               
                   
                 change location move to locations of type Y. 
               
               
                 X connectedLocation Y 
                 In Translocations of type X, the objects that 
               
               
                   
                 change location may start or end at locations of 
               
               
                   
                 type Y. 
               
               
                 Class: Dimer 
               
               
                 Class: Trimer 
               
               
                 Class: Tetramer 
               
               
                 Class: Dimerization 
               
               
                 Class: Trimerization 
               
               
                 Class: Tetramerization 
               
               
                 Class: Exposure to Ionizing Radiation 
               
               
                 Class: Centromere DNA 
               
               
                 Class: Single-Stranded DNA 
               
               
                 Class: Double-Stranded DNA 
               
               
                 Class: DNA Lesion 
               
               
                 Class: Double-Stranded DNA terminus 
               
               
                 Class: Single-Stranded DNA break 
               
               
                 Class: SecretedProtein 
               
               
                   
               
             
          
         
       
     
     It will be understood that in addition to the material listed in the table, a variety of other classes, primarily used for book-keeping, or to provide a place for objects in a unified class structure may be used in an actual implementation. For example, a high-level term, such as “Thing” may be used as the root for all classes, metaclasses and relationships. Additionally, relationships such as “X documentation Y” may be used to represent system information, such as documentation, in a knowledge base made up of case frames. 
     As seen in  FIG. 7G , case frames can be combined and interconnected to represent complex biological information, such as pathways.  FIG. 7G  shows a pathway that includes binding. 
     Referring now to  FIG. 8 , the process of creating a case frame is described. In step  802 , the knowledge source is selected. In an exemplary embodiment, the knowledge for case frames can come from text, from a human, or from a database. 
     Once the knowledge source is identified, in step  804 , the type of knowledge is determined. This is done by determining the type of entities being described (e.g. genes) and the types of relationships being imposed on the entities by the knowledge. For example, an entry for literature references of Genes represents a different type of knowledge than information about intra Gene activation and inhibition. 
     Next, at step  806 , an appropriate case frame is chosen to represent the knowledge. Based on the type of knowledge to be represented, an appropriate set of case frames can be chosen from a library of generic case frames. In some instances, an appropriate case frame may not be available. When this occurs, it may be desirable to edit an existing case frame, or to add a new case frame. 
     When the case frames in the library are incomplete, or inadequate for representing the knowledge, it may be desirable to edit an existing case frame. For example, a case frame for representing a protein binding may not have in its template a field for entering the energy level of the binding. If this is the case, a new field may be added using a user interface. In some embodiments, an expert review may be required before a permanent change or addition is made to a case frame. 
     If a needed case frame does not exist, a new type of relation may be created and its attributes described in a new type of case frame. A user interface may be used to add a new type of case frame to the library of generic or empty case frames. In some embodiments, an expert review may be required before a new case frame is added to a library. 
     In step  808 , the selected case frames are instantiated. Generally, instantiating a case frame involves filling in the blanks in the generic or empty template of the case frame. This is typically done through use of a user interface. Typically, a user reads each piece of knowledge from the original source, and fills in the fields in the Case Frame template to represent the knowledge. Once instantiated, the case frame is stored in a knowledge base for future use. 
     In step  810 , metadata, such as attributions are added to the knowledge represented in a case frame. Each piece of knowledge (i.e., each line in the case frame) has an associated attribution. An attribution is a number or code that indicates when and where the data came from: the source, the person entering it, the date, time and experimental conditions from which the piece of knowledge was derived. Other metadata or context data (e.g. from which database the knowledge was derived, what type of information is represented by the knowledge, etc.) also may be added to the knowledge represented by a case frame. 
     Many of the steps described above may be performed by a user, through a user interface. In one embodiment, the user interface for entering knowledge is designed to be fool proof and enforces an ontology. The system is pre-loaded with an ontology of relevant biological terms and relations. Through a series of searches and pull-down menus, the user selects the entities he/she wants to relate (e.g. genes, proteins, metabolites), and then selects the relation (from the case frame library) and fills in the fields. Because the user can only relate terms that are already in the ontology, the user is kept from filling in unknown terms or incorrect spellings. If a new item or term is needed, then the new item or term may be entered into the ontology by an expert administrator of the system. 
     The ontology generally provides a kind of life science “markup”, that adds meaning to life science information stored in the knowledge base, and facilitates the interconnection of pieces of information stored in the knowledge base. In accordance with an embodiment of the invention, the knowledge base provides a harmonization of life taxonomies, ontologies, and ways to make relationships. 
     In addition to permitting users to enter knowledge, knowledge may be extracted from databases. In many embodiments, the bulk of the knowledge in the knowledge base is loaded automatically. Generally, knowledge may be automatically loaded from structured databases and unstructured text sources. The databases are loaded using special purpose translation programs or software agents that translate the source format to a format compatible with the case frames. For example the source format may be a relational database or a XML file. 
     Text mining techniques are used to automatically extract knowledge from text documents. The extracted knowledge is then converted to case frames, and is loaded into the knowledge base. In some embodiments, known text mining tools, such as the products of ClearForest corporation, of New York, N.Y., the products of X-Mine Inc., of Brisbane, Calif., or text mining tools provided by Professor James Pustejovsky, of Brandeis University, of Waltham, Mass. may be used to extract relations between entities of interest. 
     As knowledge is added to the knowledge base through use of case frames, connections between the various pieces of knowledge may be formed. In some embodiments, these connections are implicit, and arise as the result of the same entity being used in multiple relationships. A knowledge base for use in the life sciences may contain well over a million pieces of knowledge, and millions of connections between those pieces of knowledge. 
       FIGS. 9-11  show example screens of a user interface used in one embodiment of the invention for creating case frames.  FIG. 9  shows a screen  850  of a user interface for searching and viewing the case frames associated with a particular chemical. In the example shown in the screen  850 , a search area  852  is used to specify a search for case frames associated with pyruvate. The results of the search are shown in a case frame list area  854 . 
     Generally, the search area  852  may be used to enter various queries on the knowledge base, permitting a user to browse through the all the knowledge associated with a particular entity, and all related entities. 
     In  FIG. 10 , a screen  900  is shown, in which a drop down menu  902  is used to permit a user to select a relationship type. An area  904  allows the user to determine terms in the ontology that may legally be entered in various parts of the relationship selected in the drop down menu  902 . 
       FIG. 11  shows a screen  1000  in which two terms in the ontology are being merged. Using a merge area  1002 , a user may specify that two terms in the ontology have the same meaning, enter a new name for the two merged terms, and view all case frames using either or both of the terms. 
     In addition to a user interface similar to the examples shown in  FIGS. 9-11 , other tools may be used to create case frames. For example, known tools for creating graph representations of knowledge, such as Knowledge Editor, available from the Genomic Sciences Center of RIKEN (the institute of physical and chemical research) Yokohama Institute, in Japan, can be used to create case frames. The output from such tools may be processed using data manipulation software, such as Perl, to generate case frames based on the output from such tools. 
     Once the knowledge base of instantiated case frames is constructed, a variety of algorithms may be applied to reason using the knowledge. Such reasoning algorithms are typically research and purpose specific. For example, reasoning algorithms may include algorithms that find the shortest path between two entities, find the shortest path between two entities that goes through a third entity, find a molecule that controls numerous other molecules (or is upstream of a process of interest), determine which enzymes and metabolites will be impacted if an enzyme is inhibited, determine what will happen if a gene is knocked out, or determine the results if multiple entities are knocked out. 
     As discussed above with reference to  FIG. 2 , the knowledge base may be viewed as a graph, containing nodes which represent entities, and edges which represent relations between the entities. By using algorithms that traverse, manipulate, or search this graph, the system is able to effectively reason about the knowledge contained in the knowledge base. One application of such algorithms is shown above, in  FIG. 9 , in which a user is able to query the knowledge base, and browse through knowledge associated with an entity and all related entities.  FIGS. 12 and 13  show another example application of such algorithms, in which the system reasons about pathways. 
       FIG. 12  shows a screen  1200 , in which a graph theory-based search algorithm is used to look for all the pathways between two metabolites. In a selection area  1202 , the user selects the two metabolites—Zymosterol and Ergosterol, in this example. In a pathway results area  1204 , the system displays a list of possible pathways, based on a graph theory-based search of the knowledge base. 
     Once these pathways have been found in the graph, a graphical representation of the pathways may be generated. In  FIG. 13 , screen  1300  shows such a graphical representation of the pathways between two metabolites. This graphical representation may be automatically generated by the system, an may be used by scientists to understand the pathways and the mechanism of action of any perturbations being made to the system and the resulting experimental results. 
     Referring now to  FIG. 14 , an overview of one embodiment of a system according to the invention that combines these knowledge acquisition and manipulation capabilities is described. The system  1400  includes one or more knowledge bases  1404 , a discovery environment  1406 , an inference engine  1408 , and a data harmonization and transformation module  1410 . 
     The knowledge bases  1404  contain life science knowledge that is created, stored, and organized as described hereinabove. In some embodiments, the knowledge bases may be multi-tiered. A user  1414  may have a personal knowledge base (also referred to as a “sandbox”), which incorporates specialized pieces of knowledge that the user has entered. The user  1414  may also access a group knowledge base, a departmental knowledge base, a company knowledge base, etc. 
     Each level in this multi-tiered access scheme may include access to other levels. Thus, when accessing a personal knowledge base, the user  1414  may access knowledge (and implicit connections between knowledge items) in the personal knowledge base, combined with the knowledge in the group knowledge base, the departmental knowledge base, and so on. 
     In addition to storing knowledge, the knowledge base  1404  may store agents definitions, the ontology, and other data that is used by the system  1400 . 
     The discovery environment  1406  provides a user interface through which the user  1414  may access knowledge in the knowledge bases  1404 , and other knowledge bases accessible through the system  1400 . Additionally, the discovery environment  1406  may include discovery tools, that may be used to automatically reason about information contained in the knowledge bases  1404 . For example, a tool for automatically discovering and displaying pathways, such as is shown above with reference to  FIGS. 13 and 14  may be a part of the discovery environment  1406 . Alternatively, some tools for reasoning about the knowledge stored in the knowledge bases  1404  may be included in the inference engine  1408 . 
     The inference engine  1408  manages the life sciences ontology that is used, for example, when new entries are added to the knowledge bases  1404 . Additionally the inference engine  1408  manages knowledge agents, that automatically create connections or relationships between entries in the knowledge bases  1404 , based on rules. 
     The data harmonization and transformation module  1410  manages data integration agents, which keep the knowledge bases  1404  up to date from various legacy and public sources. Such data integration agents may periodically access various sources of life sciences data, and translate such data into a form that may be integrated into the knowledge bases  1404 . Integration of such data into the knowledge bases  1404  may involve automatically generating appropriate relations within the data that is being integrated, and between the data that is being integrated and other data and entities in the knowledge bases  1404 . This task may be handled by the knowledge agents of the inference engine  1408 . 
     In addition to providing access to knowledge stored in the knowledge bases  1404 , the system  1400  may provide access to various external knowledge bases  1412 . The external knowledge bases  1412  may include knowledge bases assembled by universities, other researchers, companies, and so on. Additionally, such external knowledge bases may include agent definitions, ontologies, and other data that may be used by the system  400 . 
     Access to any particular external knowledge base may be controlled through a managed account interface  1413 . The managed account interface  1413  may be used to restrict access to various external knowledge bases, or to permit only selected portions of such knowledge bases to be accessed externally. For example, the managed account interface  1413  may be used to permit external access to a knowledge base only to a set of subscribers. Additionally, managed account interface  1413  may manage a directory, log files log, and update history information. 
     In some embodiments, Discovery Environment  1406  may include a managed account interface (not shown) similar to managed account interface  1413 . Such an interface can be used to identify users, restrict access, keep logs, manage updates, manage a directory, and other similar administrative tasks. 
     As discussed above, in some embodiments, the knowledge base may be multi-tiered, and may include access restrictions. As shown in  FIG. 15 , portions of the knowledge base may be proprietary. These proprietary portions may only be accessed by the owner of the proprietary information. Information in the proprietary sections of the knowledge base may be linked to other information within the knowledge base. 
     Knowledge base  1500  includes a public knowledge base  1502 , a subscriber knowledge base  1504 , and proprietary knowledge bases  1506  and  1508 . The public knowledge base  1502  contains life science information that may be accessed by members of the public  1510 . Subscribers  1512  may access everything in the public knowledge base  1502 , as well as the information in the subscriber knowledge base  1504 . Information in the subscriber knowledge base  1504  may have greater commercial value than the information in the public knowledge base  1502 . 
     The proprietary knowledge base  1506  may add information to the knowledge base  1500  that is owned by a particular individual or company. A user  1514  who has legitimate access to the proprietary knowledge base  1506  is able to access all of the information in the proprietary knowledge base  1506 , the subscriber knowledge base  1504 , and the public knowledge base  1502 . All of this information will appear to the user  1514  to be interrelated, to form a seamless whole. The information stored in the proprietary knowledge base  1506 , and the relationships between that information and information stored in other portions of knowledge base  1500  will only be visible to users, such as the user  1514 , who have access to the proprietary knowledge base  1506 . 
     Similarly, the proprietary knowledge base  1508  may only be accessed by users, such as a user  1516 , who have legitimate access to the proprietary knowledge base  1508 . The user  1516  does not have access to the proprietary knowledge base  1506 , and is unable to access any of the information or relations with information in the proprietary knowledge base  1506 . The user  1514  does not have access to the proprietary knowledge base  1508 , and is therefore unable to access to any of the information or relations with information in the proprietary knowledge base  1508 . Similarly, subscribers  1512 , and the public  1510  are unable to access information or relations to information in either of the proprietary knowledge bases  1506  or  1508 . Access to information in these proprietary knowledge bases is blocked by security measures  1518 . 
     In accordance with the invention, case frames relating life sciences information may be used to represent all aspects of the functioning and structure of biological systems and their components. Thus, while the majority of this specification speaks in terms of biochemical data at the physiologic level, case frames may be used to represent interactions at the levels of ions and atoms, nucleic acid, protein, and metabolite biochemistry, organelles, subcellular compartments, cells, tissue compartments, tissues, organs, organ systems, individuals, populations, diet, diseased states, clinical trials, epidemiology, predator prey interactions, and parasite-host interactions. 
     Examples of biological systems in the human context include, but are not limited to, the integument, skeletal, muscular, nervous, endocrine, cardiovascular, immune, circulatory, respiratory, digestive, urinary, and reproductive systems. In one particular example, case frames could be used to represent the functioning and structure of skeletal muscle fibers in the muscular system. In another example, case frames could be used to represent the functioning of neural control of muscle fiber contraction in the skeletal system. In further examples, case frames could be used to represent the functioning and structure of pathways for visceral motor output or the functioning of synaptic communication in neural tissue in the nervous system. In other examples, case frames could be used to represent the functioning and structure of cardiac cycle and control of heart rate in the cardiovascular system. In yet other examples, case frames could be used to represent the functioning and structure of lymphocytes and immune response in the lymphatic system. 
     Examples of cells modeled using case frame technology include, but are not limited to, epithelial cells, nerve cells, blood cells, connective tissue cells, smooth muscle cells, skeletal muscle cells, fat cells, ovum cells, sperm cells, and stem cells. Examples of cell functions include, but are not limited to, cell division, cell regulation, control of cellular activity by the nucleus, and cell-to-cell signaling. Case frames may be used to represent the functioning and structure of cellular components. Examples of cellular components include, but are not limited to, the cytoplasm, cytoskeleton, ribosomes, mitochondria, nucleus, endoplasmic reticulum (ER), Golgi apparatus, and lysosomes. 
     In a further embodiment, case frames may be used to represent the structure, function and synthesis of proteins. In addition, case frames could be used to represent components of proteins, including, but not limited to, amino acid sequence, secondary and tertiary structure, conformation data. Furthermore, case frames could be used to represent molecules associated with proteins, including, but not limited to, enzymes. 
     In another embodiment, case frames from life sciences information are used to represent the structure, function and synthesis of nucleic acids. Nucleic acids are not limited to any particular type of nucleic acid and include, but are not limited to, total genome DNA, cDNA RNA, mRNA, tRNA, and rRNA. In another embodiment, case frames from life sciences information are used to represent the structure and function of DNA replication, DNA repair, and DNA recombination. In a further embodiment of the invention, case frames identify, for example, a single nucleotide polymorphism (SNP), a splice variant, microRNA, double-stranded RNA (dsRNA), small interfering RNA (also known as short interfering RNA or siRNA), RNA interference (RNAi), a chromosome, a chromosomal modification or a silenced gene. 
     In yet another embodiment, case frames from life sciences information are used to represent cancer pathways, including, but not limited to, the functioning of oncogenes and tumor suppressor genes. For example, gene expression of the human p53 tumor suppressor gene is shown as multiple case frames in  FIG. 7C . In another embodiment of the invention, case frames may be used to represent the pathways for various types of cancer, including, but not limited to, cancers of the blood, stomach, lung, liver, pancreas, prostate, kidney, testes, bladder, uterus, colon and rectum. 
     In a further another embodiment, case frames from life sciences information are used to represent the pathways for various types of diseases, including, but not limited to, the functioning of molecular mechanisms underlying diseases. Examples of diseases include, but are not limited to, cardiovascular, coronary, pulmonary, respiratory, hematologic, neurological, psychiatric, neuropsychological, neuromuscular, musculoskeletal, ophthalmological, gastrointestinal, genitourinary, endocrinal, dermatologic, inflammatory, metabolic, pathogenic, and infectious diseases. 
     In another embodiment of the invention, case frames include patient data. Patient data may include data of phenotypic or genotypic nature. For example, patient data could include, but is not limited to, LDL level, cholesterol level, and white blood cell level. In other examples, patient data includes, but is not limited to, diagnosis of congestive heart failure (CHF) and diagnosis of end stage renal disease (ESRD). In a further example, genotypic patient data includes, but is not limited to, detection of single nucleotide polymorphisms (SNPs). 
     In one embodiment of the invention, case frames from life sciences information identify a product relationship. Examples of such relationships include, but are not limited to, the following: drug X inhibits a specific function of molecule Y; chemical X acts as a drug; chemical X is in a published patent; chemical X is used to treat disease Y; chemical X inhibits the activity of entity Y; and chemical X activates the ABC activity of entity Y. 
     In yet another embodiment, case frames can identify experiments that are linked to characteristics and parameters. For example, a case frame could identify an experiment that links a result file or a protocol file from the experiment. In another example, a case frame could identify that an experiment was conducted by a particular person or facility. In a further example, a case frame could identify that an experiment has one or more sub-experiments or mini-experiments. In another embodiment of the invention, case frames could identify and relate data from an animal experiment or tissue type used in an experiment. 
     In another embodiment, case frames may be used to represent the functioning and structure of infectious agents. Examples of such infectious agents include, but are not limited to, viruses, bacteria, yeasts fungi, or other microorganisms such as parasites. In yet another embodiment, case frames identify a pathogen such as a virus, bacteria, fungus or prion, with relationship connectors representing implications in specific diseases and other characteristics. In other embodiments of the invention, case frames identify that a particular measurable entity is a biomarker for a disease state, drug efficacy, or patient stratification, identify the relationship between model organisms, tissues or other biological models of disease, and the relevant disease(s), or an epidemic and its characteristics. 
     In another embodiment, case frames identify a disease that links to characteristics, biomarkers, mechanisms, or genes. For example, a case frame could link breast cancer with the BRCA-1 gene. As another example, a case frame could link chronic lymphocytic leukemia (CLL) with the Bcl2 gene. In a further embodiment, case frames identify a population with relationship connectors representing characteristics. For example, a case frame could identify a certain population as having a high incidence of sickle cell anemia or breast cancer. In another embodiment of the invention, case frames identify a xenograft model. In a further embodiment of the invention, case frames identify a cell line and its characteristics. For example, a case frame could identify a cell line having a mutant k-Ras gene and a normal p53 gene. 
     Although case frames of the invention have been described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. In accordance with the invention, case frames may be used to represent any life-science information. 
     In some embodiments, the functionality of the systems and methods described above may be implemented as software on a general purpose computer. In such an embodiment, the program may be written in any one of a number of high-level languages, such as FORTRAN, PASCAL, C, C++, LISP, JAVA, or BASIC. Further, the program may be written in a script, macro, or functionality embedded in commercially available software, such as EXCEL or VISUAL BASIC. Additionally, the software could be implemented in an assembly language directed to a microprocessor resident on a computer. For example, the software could be implemented in Intel 80×86 assembly language if it were configured to run on an IBM PC or PC clone. The software may be embedded on an article of manufacture including, but not limited to, a “computer-readable medium” such as a floppy disk, a hard disk, an optical disk, a magnetic tape, a PROM, an EPROM, or CD-ROM. 
     While the invention has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.