Reference number : GC-2017-Q1-02572, amendment number : , agreement type : G, recipient legal name : Oko, Richard (Queen’s University), recipient country : CA, recipient province : nan, recipient city : Ontario, recipient postal code : nan, program name english : Discovery Grants Program - Individual, program name french : Programme de subventions à la découverte - individuelles, program purpose english : Fertilization is the cornerstone of development where the two differentiated cells, sperm and egg, set the stage for embryogenesis, for which competency of the gametes is essential. Yet only rudimentary knowledge is available on the molecules and mechanisms involved in sperm-egg interactions leading to zygotic development. Our long term goal is to gain an understanding of these mechanisms. Our approach is to molecularly dissect sperm compartments, such as the acrosome and perinuclear theca, that are implicated in the fertilization process. The identities of these proteins provide clues to their significance and lead to the design of specific probes and experiments to test their predicted fertilization functions. This strategy has been successful as we have discovered novel sperm proteins that are implicated in the penetration of the egg and its activation during fertilization, leading to the development of biomarkers and synthetic molecules for the detection and treatment of infertility. Understanding the events that occur when an egg is first fertilized leads to application of how we can influence those events and improve reproduction in livestock and humans. 
 
 
Utilizing this proteomic approach has led my lab to propose that the perinuclear theca (PT), a proteinaceous cap surrounding the sperm nucleus, is divided into two functional regions: the subacrosomal part , containing proteins involved in acrosomal assembly and the postacrosomal part , containing proteins involved in sperm/egg interactions during fertilization. The major goal of this proposal is to determine the significance of several key sperm PT proteins we have identified: namely, a group of core somatic histones (H3, H2B, H2A and H4), whose unprecedented cytosolic location in the postacrosomal region of the sperm head suggests a role in chromatin remodeling of the male pronucleus during fertilization and Glutathione-S-Transferase Omega 2 (GSTO2) , whose similar location suggests a role in regulating the oxidative and reductive state of covalently-linked molecules, especially during the disassembly of the sperm nucleus during fertilization. By functional deactivation of these proteins we will test their proposed mechanisms of action during fertilization and determine if they are required for zygotic development. 
 
 
The four specific hypotheses to be tested are: 1. The presence of Core histones and GSTO2 in the PT is a common eutherian sperm feature. 2. Core histones and GSTO2 are synthesized de novo during spermiogenesis and assembled as part of the PT by the microtubular manchette. 3. PT core histones dissolve in the ooplasm during fertilization and contribute by stabilizing the DNA of the decondensing sperm nucleus in preparation for pronuclear formation. 4. PT anchored GSTO2 dissolves in the ooplasm during fertilization and utilizes glutathione in the reduction of S-S bonds between protamines to decondense the sperm nucleus., program purpose french : Fertilization is the cornerstone of development where the two differentiated cells, sperm and egg, set the stage for embryogenesis, for which competency of the gametes is essential. Yet only rudimentary knowledge is available on the molecules and mechanisms involved in sperm-egg interactions leading to zygotic development. Our long term goal is to gain an understanding of these mechanisms. Our approach is to molecularly dissect sperm compartments, such as the acrosome and perinuclear theca, that are implicated in the fertilization process. The identities of these proteins provide clues to their significance and lead to the design of specific probes and experiments to test their predicted fertilization functions. This strategy has been successful as we have discovered novel sperm proteins that are implicated in the penetration of the egg and its activation during fertilization, leading to the development of biomarkers and synthetic molecules for the detection and treatment of infertility. Understanding the events that occur when an egg is first fertilized leads to application of how we can influence those events and improve reproduction in livestock and humans. 
 
 
Utilizing this proteomic approach has led my lab to propose that the perinuclear theca (PT), a proteinaceous cap surrounding the sperm nucleus, is divided into two functional regions: the subacrosomal part , containing proteins involved in acrosomal assembly and the postacrosomal part , containing proteins involved in sperm/egg interactions during fertilization. The major goal of this proposal is to determine the significance of several key sperm PT proteins we have identified: namely, a group of core somatic histones (H3, H2B, H2A and H4), whose unprecedented cytosolic location in the postacrosomal region of the sperm head suggests a role in chromatin remodeling of the male pronucleus during fertilization and Glutathione-S-Transferase Omega 2 (GSTO2) , whose similar location suggests a role in regulating the oxidative and reductive state of covalently-linked molecules, especially during the disassembly of the sperm nucleus during fertilization. By functional deactivation of these proteins we will test their proposed mechanisms of action during fertilization and determine if they are required for zygotic development. 
 
 
The four specific hypotheses to be tested are: 1. The presence of Core histones and GSTO2 in the PT is a common eutherian sperm feature. 2. Core histones and GSTO2 are synthesized de novo during spermiogenesis and assembled as part of the PT by the microtubular manchette. 3. PT core histones dissolve in the ooplasm during fertilization and contribute by stabilizing the DNA of the decondensing sperm nucleus in preparation for pronuclear formation. 4. PT anchored GSTO2 dissolves in the ooplasm during fertilization and utilizes glutathione in the reduction of S-S bonds between protamines to decondense the sperm nucleus., agreement title english : The origin and compartmentalization of core somatic histones and GSTO2 in sperm and their role in fertilization, agreement title french : The origin and compartmentalization of core somatic histones and GSTO2 in sperm and their role in fertilization, agreement number : RGPIN, agreement value : 200000.0, agreement start date : 2017-05-10, agreement end date : nan, description english : nan, description french : nan, expected results english : nan, expected results french : nan, additional information english : Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023), additional information french : Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023), owner organization : nserc-crsng, owner organization title : Natural Sciences and Engineering Research Council of Canada | Conseil de recherches en sciences naturelles et en génie du Canada