bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistical genetics of molar cusp patterning in pedigreed baboons: Implications for primate dental development and evolution
Authors: Hlusko Leslea J. , Maas Mary‐Louise , Mahaney Michael C. 
Published: June 2004

AbstractGene expression and knock‐out studies provide considerable information about the genetic mechanisms required for tooth organogenesis. Quantitative genetic studies of normal phenotypic variation are complementary to these developmental studies and may help elucidate the genes and mechanisms that contribute to the normal population‐level phenotypic variation upon which selection acts. Here we present the first quantitative genetic analysis of molar cusp positioning in mammals. We analyzed quantitative measures of molar cusp position in a captive pedigreed baboon breeding colony housed at the Southwest National Primate Research Center in San Antonio, Texas. Our results reveal complete pleiotropy between antimeric pairs of traits – i.e., they are influenced by the same gene or suite of genes. Mandibular morphological homologues in the molar series also exhibit complete pleiotropy. In contrast, morphological homologues in maxillary molar series appear to be influenced by partial, incomplete pleiotropic effects. Variation in the mandibular mesial and distal molar loph orientation on the same molar crown is estimated to be genetically independent, whereas the maxillary molar mesial and distal loph orientation is estimated to have partially overlapping genetic affects. The differences between the maxillary and mandibular molar patterning, and the degree of genetic independence found between lophs on the same molar crown, may be indicative of previously unrecognized levels of modularity in the primate dentition. J. Exp. Zool. (Mol. Dev. Evol.) 302B:268–283, 2004. © 2004 Wiley‐Liss, Inc.
Thomas Henry Huxley (1825–1895) puts us in our place
Authors: Weiss Kenneth M. 
Published: June 2004

AbstractThomas Huxley was one of the 19thcentury's most active defenders of Darwin's idea that life has evolved through natural processes. An anatomist and paleontologist, he extended his energies to science and education policy, the democratization of science, and the broad societal implications of evolution. Since his time the fossil record has greatly improved and the genetic ‘revolution’ has occurred, deepening our understanding of primate and human evolution in ways that would please Huxley: improved systematics relies heavily on genetic data, and molecular technologies are opening our understanding of the genetic basis of complex traits of traditional anthropological interest—but in ways that are thoroughly dependent on the fact of evolution. A more unified biological synthesis is forming that unites genes, developmental process, structure, and inheritance. But the tempo and mode of evolution remain unresolved. Huxley was one of many who have had trouble accepting Darwin's gradual natural selection as the central evolutionary mechanism, and views spanning the antipodes of gradualism and saltation find advocates even in our genetic era.J. Exp. Zool. (Mol. Dev. Evol.) 302B:196–206, 2004.© 2004 Wiley‐Liss, Inc.
Craniofacial variability and modularity in macaques and mice
Authors: Hallgrímsson Benedikt , Willmore Katherine , Dorval Curtis , Cooper David M.L. 
Published: June 2004

AbstractEvolutionary developmental biology of primates will be driven largely by the developmental biology of the house mouse. Inferences from how known developmental perturbations produce phenotypic effects in model organisms, such as mice, to how the same perturbations would affect craniofacial form in primates must be informed by comparisons of phenotypic variation and variability in mice and the primate species of interest. We use morphometric methods to compare patterns of cranial variability in homologous datasets obtained for two strains of laboratory mice and rhesus macaques. C57BL/6J represents a common genetic background for transgenic models. A/WySnJ mice exhibit altered facial morphology which results from reduction in the growth of the maxillary process during formation of the face. This is relevant to evolutionary changes in facial prognathism in nonhuman primate and human evolution. Rhesus macaques represent a nonhuman primate about which a great deal of phenotypic and genetic information is available. We find significant similarities in covariation patterns between the C57BL/6J mice and macaques. Among‐trait variation in genetic and phenotypic variances are fairly concordant among the three groups, but among‐trait variation in developmental stability is not. Finally, analysis of modularity based on phenotypic and genetic correlations did not reveal a consistent pattern in the three groups. We discuss the implications of these results for the study of evolutionary developmental biology of primates and outline a research strategy for integrating mouse genomics and developmental biology into this emerging field.J. Exp. Zool. (Mol. Dev. Evol.) 302B:207–225, 2004.© 2004 Wiley‐Liss, Inc.
Modularity and integration in the hominoid scapula
Authors: Young Nathan 
Published: June 2004

AbstractIn this paper, several hypotheses of morphological integration within the hominoid (ape) scapula are tested. In particular, whether the scapula represents a set of developmental tissues sharing tight correlations between constituent parts (i.e., highly integrated) or is more modularly organized (i.e., covariation is greater within regions than between) is tested. Whether the patterns of integration in the scapula have changed over phylogenetic time or in response to selective forces is also examined. Results from two different analyses (matrix correlations and edge deviance) indicate traits comprising the blade and acromion, and to a weaker degree the glenoid, correlate highly with each other. The coracoid exhibits more independence from other parts of the scapula, perhaps reflecting its distinct evolutionary developmental history. Overall, similarity in species‐specific patterns of correlation was high between all taxa. Correlation matrix similarity was significantly correlated with functional similarity and morphological distance, but not with phylogenetic distance. These results are congruent with other studies of integration that suggest correlation patterns remain stable over evolutionary time. There are changes associated with phylogeny, but the tight link between functional similarity and phylogenetic distance at this level of comparison presents possible challenges to interpretation. Overall similarities in the pattern of integration in all taxa might be better interpreted as relative strengthening or weakening of trait correlations rather than broadscale changes in the pattern of relationship between developmental regions. Larger sample sizes with greater taxonomic/functional breadth, and finer scale analyses of patterns of correlation are needed to test these hypotheses further. J. Exp. Zool. (Mol. Dev. Evol.) 302B:226–240, 2004. © 2004 Wiley‐Liss, Inc.
Testing hypotheses about tinkering in the fossil record: the case of the human skull
Authors: Lieberman Daniel E. , Krovitz Gail E. , McBratney‐Owen Brandeis 
Published: June 2004

AbstractEfforts to test hypotheses about small‐scale shifts in development (tinkering) that can only be observed in the fossil record pose many challenges. Here we use the origin of modern human craniofacial form to explore a series of analytical steps with which to propose and test evolutionary developmental hypotheses about the basic modules of evolutionary change. Using factor and geometric morphometric analyses of craniofacial variation in modern humans, fossil hominids, and chimpanzee crania, we identify several key shifts in integration (defined as patterns of covariation that result from interactions between components of a system) among units of the cranium that underlie the unique shape of the modern human cranium. The results indicate that facial retraction in modern humans is largely a product of three derived changes: a relatively longer anterior cranial base, a more flexed cranial base angle, and a relatively shorter upper face. By applying the Atchley‐Hall model of morphogenesis, we show that these shifts are most likely the result of changes in epigenetic interactions between the cranial base and both the brain and the face. Changes in the size of the skeletal precursors to these regions may also have played some role. This kind of phenotype‐to‐genotype approach is a useful and important complement to more standard genotype‐to‐phenotype approaches, and may help to identify candidate genes involved in the origin of modern human craniofacial form. J. Exp. Zool. (Mol. Dev. Evol.) 302B:284–301, 2004. © 2004 Wiley‐Liss, Inc.
Kinematics of cranial ontogeny: Heterotopy, heterochrony, and geometric morphometric analysis of growth models
Authors: Zollikofer Christoph Peter Eduard , Ponce De León Marcia Silvia 
Published: June 2004

AbstractIn this paper, we examine the relationship between the classical concepts of heterotopy, heterochrony and ontogenetic allometry as descriptive and as explanatory categories in the investigation of evolutionary developmental novelty in the hominid skull. We use concepts of kinematic analysis of locomotion to propose a methodological framework for the kinematic analysis of cranial form change during ontogeny. We argue that a combination of geometric‐morphometric methods with graphics visualization tools currently represents the most adequate means to analyze the kinematics of ontogeny. Using cranial growth models, we simulate how evolutionary modifications of developmental processes impinge on morphological patterns of ontogeny, and explore how differences in ontogenetic patterns can tentatively be traced back to underlying process differences. Our analyses indicate that minor alterations in growth parameters elicit complex patterns of ontogenetic modification that are difficult to describe with the standard repertoire of heterochronic terminology. The proposed kinematic and model‐based approach is used in a comparative analysis of cranial ontogeny in Neanderthals and anatomically modern humans, indicating that early ontogenetic modification of a small set of growth parameters is a major source of evolutionary novelty during hominid evolution.J. Exp. Zool. (Mol. Dev. Evol.) 302B:322‐340, 2004.© 2004 Wiley‐Liss, Inc.
The anthropoid postcranial axial skeleton: Comments on development, variation, and evolution
Authors: Pilbeam David 
Published: June 2004

AbstractWithin‐species phenotypic variation is the raw material on which natural selection acts to shape evolutionary change, and understanding more about the developmental genetics of intraspecific as well as interspecific phenotypic variation is an important component of the Evo‐Devo agenda. The axial skeleton is a useful system to analyze from such a perspective. Its development is increasingly well understood, and between‐species differences in functionally important developmental parameters are well documented. I present data on intraspecific variation in the axial postcranial skeleton of some Primates, including hominoids (apes and humans). Hominoid species are particularly valuable, because counts of total numbers of vertebrae, and hence original somite numbers, are available for large samples. Evolutionary changes in the axial skeleton of various primate lineages, including bipedal humans, are reviewed, and hypotheses presented to explain the changes in terms of developmental genetics. Further relevant experiments on model organisms are suggested in order to explore more fully the differences in developmental processes between primate species, and hence to test these hypotheses. J. Exp. Zool. (Mol. Dev. Evol.) 302B:241–267, 2004. © 2004 Wiley‐Liss, Inc.
Accurate assessment of the arterial input function during high‐dose myocardial perfusion cardiovascular magnetic resonance
Authors: Gatehouse Peter D. , Elkington Andrew G. , Ablitt Nicholas A. , Yang Guang‐Zhong , Pennell Dudley J. , Firmin David N. 
Published: June 2004

AbstractPurposeTo develop a method for accurate measurement of the arterial input function (AIF) during high‐dose, single‐injection, quantitative T1‐weighted myocardial perfusion cardiovascular magnetic resonance (CMR).Materials and MethodsFast injection of high‐dose gadolinium with highly T1 sensitive myocardial perfusion imaging is normally incompatible with quantitative perfusion modeling because of distortion of the peak of the AIF caused by full recovery of the blood magnetization. We describe a new method that for each cardiac cycle uses a low‐resolution short‐axis (SA) image with a short saturation‐recovery time immediately after the R‐wave in order to measure the left ventricular (LV) blood pool signal, which is followed by a single SA high‐resolution image with a long saturation‐recovery time in order to measure the myocardial signal with high sensitivity. Fifteen subjects were studied. Using the new method, we compared the myocardial perfusion reserve (MPR) with that obtained from the dual‐bolus technique (a low‐dose bolus to measure the blood pool signal and a high‐dose bolus to measure the myocardial signal).ResultsA small significant difference was found between MPRs calculated using the new method and the MPRs calculated using the dual‐bolus method.ConclusionThis new method for measuring the AIF introduced no major error, while removing the practical difficulties of the dual‐bolus approach. This suggests that quantification of the MPR can be achieved using the simple high‐dose single‐bolus technique, which could also image multiple myocardial slices. J. Magn. Reson. Imaging 2004;20:39–45. © 2004 Wiley‐Liss, Inc.
Biolistic expression of the macrophage colony stimulating factor receptor in organotypic cultures induces an inflammatory response
Authors: Mitrasinovic Olivera M. , Robinson Christopher C. , Tenen Daniel G. , Lee Yuen Ling , Poon Clara , Murphy Greer M. 
Published: June 2004

AbstractThe receptor for macrophage colony‐stimulating factor (M‐CSFR; c‐fms) is expressed at increased levels by microglia in Alzheimer's disease (AD) and in mouse models for AD. Increased expression of M‐CSFR on cultured microglia results in a strong proinflammatory response, but the relevance of this cell culture finding to intact brain is unknown. To determine the effects of increased microglial expression of M‐CSFR in a complex organotypic environment, we developed a system for biolistic transfection of microglia in hippocampal slice cultures. The promoter for the Mac‐1 integrin α subunit CD11b is active in cells of myeloid origin. In the brain, CD11b expression is restricted to microglia. Constructs consisting of the promoter for CD11b and a c‐fms cDNA or an enhanced green fluorescent protein (EGFP) cDNA were introduced into monotypic cultures of microglia, neurons, and astrocytes. Strong CD11b promoter activity was observed in microglia, whereas little activity was observed in other cell types. Biolistic transfection of organotypic hippocampal cultures with the CD11b/c‐fms construct resulted in expression of the c‐fms mRNA and protein that was localized to microglia. Furthermore, biolistic overexpression of M‐CSFR on microglia resulted in significantly increased production by the hippocampal cultures of the proinflammatory cytokines interleukin (IL)‐1α macrophage inflammatory protein (MIP‐1α), and trends toward increased production of IL‐6 and M‐CSF. These findings demonstrate that microglial overexpression of M‐CSFR in an organotypic environment induces an inflammatory response, and suggest that increased microglial expression of M‐CSFR could contribute to the inflammatory response observed in AD brain. © 2004 Wiley‐Liss, Inc.
Constitutive Ras activity induces hippocampal hypertrophy and remodeling of pyramidal neurons in synRas mice
Authors: Gärtner Ulrich , Alpár Alán , Reimann Frank , Seeger Gudrun , Heumann Rolf , Arendt Thomas 
Published: June 2004

AbstractThe small G protein Ras, which is involved critically in neurotrophic signal transduction, has been implicated in neuronal plasticity of both the developing and the adult nervous systems. In the present study, the cumulative effects of constitutive Ras activity from early in postnatal development into the adult upon the morphology of hippocampal pyramidal neurons were investigated in synRas mice overexpressing Val12‐Ha‐Ras postmitotically under the control of the rat synapsin I promoter. In synRas mice, stereologic investigations revealed hypertrophy of the hippocampus associated with an increase in perikaryal size of pyramidal neurons within the CA2/CA3 region and the gyrus dentatus. Morphometric analyses of Lucifer Yellow‐filled CA1 pyramidal neurons, in addition, demonstrated considerable expansion of dendritic arbors. The increase in basal dendritic size was caused primarily by alterations of intermediate and distal segments and was associated with an enlarged dendritic surface. Apical dendrites showed similar but more moderate changes, which were attributed mainly to elongation of terminal segments. Sholl analyses illustrated higher complexity of both basal and apical trees. Despite significant morphologic alterations, dendritic arbors preserve their major design principles. The synaptic density within the stratum radiatum of CA1 remained unchanged; however, increases in the total hippocampal volume and in apical dendritic size imply an increment in the absolute number of synaptic contacts. The data presented here suggest a critical involvement of Ras dependent signaling in morphoregulatory processes during the maturation and in the maintenance of hippocampal pyramidal neurons. © 2004 Wiley‐Liss, Inc.
A sulfatase regulating the migratory potency of oligodendrocyte progenitor cells through tyrosine phosphorylation of β‐catenin
Authors: Kakinuma Yoshihiko , Saito Fumiji , Ohsawa Shizue , Furuichi Teiichi , Miura Masayuki 
Published: June 2004

AbstractBy using cDNA subtraction, we identified an extracellular sulfatase (RsulfFP1) from rat oligodendrocyte progenitor cells (OPCs) whose mRNA expression is down‐regulated by tumor necrosis factor‐α. RsulfFP1 mRNA was expressed specifically in the floor plate and the ventral portion of the rat spinal cord at E15. The expression pattern of RsulfFP1 overlapped with the OPCs, which are also located at the ventral region of the ventricular zone. After this stage, RsulfFP1 expression was attenuated, and the OPCs efficiently migrated throughout the spinal cord. The modification of CG‐4 cells, a cell line established from rat O2A cells, by RsulfFP1 activated canonical Wnt signaling. Furthermore, the deletion of RsulfFP1 expression by an antisense oligonucleotide caused impairment of OPC migration in rat spinal cord slice culture. Modification of cells by RsulfFP1 resulted in the increased tyrosine phosphorylation of immunoprecipitated β‐catenin, suggesting that sulfation of the extracellular matrix induced by this sulfatase might be responsible for an increase in Wnt signaling that is involved in the migration of OPCs. Thus, the present study revealed that a sulfatase is responsible for the migration of OPCs and activates intracellular mechanisms that regulate migration. © 2004 Wiley‐Liss, Inc.
Differential roles for neuropeptide Y Y1 and Y5 receptors in anxiety and sedation
Authors: Sørensen Gunnar , Lindberg Camilla , Wörtwein Gitta , Bolwig Tom G. , Woldbye David P.D. 
Published: June 2004

AbstractCentral administration of neuropeptide Y (NPY) causes both anxiolysis and sedation. Previous studies suggest that both effects are mediated via NPY Y1 receptors. However, most of these studies were carried out before the advent of specific NPY receptor ligands. Therefore, a potential role for other NPY receptors in anxiety and sedation remains a possibility. In the present study, we addressed this issue by testing the effects of intracerebroventricular (i.c.v.) injection of NPY as well as specific receptor agonists for the Y1 receptor ([D‐His26]NPY), Y2 receptor (C2‐NPY), and Y5 receptor ([cPP1–7,NPY19–23,Ala31,Aib32,Gln34]hPP) in the elevated plus maze and open field tests. As with NPY, the Y1 agonist had a dose‐dependent anxiolytic‐like effect in both behavioral tests. In contrast to NPY, which caused significant sedation in the open field test, the Y1 agonist was without sedative effect. The Y2 agonist showed neither anxiolytic‐like nor sedative effects. The Y5 agonist showed anxiolytic‐like activity in both behavioral tests and caused sedation in the same dose range as NPY in the open field test. These results indicate that anxiolytic‐like effects of i.c.v.‐administered NPY in rats are mediated via both Y1 and Y5 receptors, whereas sedation is mediated via Y5 receptors. © 2004 Wiley‐Liss, Inc.
Functional reconstitution of γ‐secretase through coordinated expression of presenilin, nicastrin, Aph‐1, and Pen‐2
Authors: Periz Goran , Fortini Mark E. 
Published: June 2004

AbstractThe γ‐secretase complex has emerged as an unusual membrane‐bound aspartyl protease with the ability to cleave certain substrate proteins at peptide bonds believed to be buried within the hydrophobic environment of the lipid bilayer. This cleavage is responsible for a key biochemical step in signaling from several different cell‐surface receptors, and it is also crucial in generating the neurotoxic amyloid peptides that are central to the pathogenesis of Alzheimer's disease. Active γ‐secretase is a multimeric protein complex consisting of at least four different proteins, presenilin, nicastrin, Aph‐1, and Pen‐2, with presenilin serving as the catalytically active core of the aspartyl protease. Presenilin itself undergoes endoproteolytic maturation, a process that is tightly regulated during the assembly and maturation of γ‐secretase, and that depends on the three cofactors nicastrin, Aph‐1, and Pen‐2. Recent studies have demonstrated that presenilin and its three cofactors are likely to be the major proteins needed for functional reconstitution of active γ‐secretase and have begun to elucidate the specific functions of the cofactors in the ordered assembly of γ‐secretase. Published 2004 Wiley‐Liss, Inc.
Dielectric properties of frozen maltodextrin solutions with added NaCl across the glass transition
Authors: Kilmartin Paul A , Reid David S , Samson Irene 
Published: June 2004

AbstractThe change in the dielectric properties of frozen 200 g kg−1 maltodextrin solutions upon warming has been recorded using a capacitance meter and a dielectric thermal analysis instrument. The capacitance and permittivity increased by several orders of magnitude after melting, and higher values were obtained at a higher measurement frequency or with added NaCl, while a marked increase (labelled Trise) was seen close to the glass transition temperatures measured by differential scanning calorimetry. The transition temperatures shifted to more negative values by 4–6 °C upon the addition of 0.1 mol kg−1 NaCl, consistent with the freezing point depression of the freeze‐concentrated solutions. Copyright © 2004 Society of Chemical Industry
Management of lentigo maligna and lentigo maligna melanoma: Seminars in surgical oncology
Authors: Arlette John P. , Trotter Martin J. , Trotter Theresa , Temple Claire L.F. 
Published: June 2004

AbstractLentigo maligna (LM) and lentigo maligna melanoma (LMM) represent a character, histogenetic subclass of melanocytic malignancies. They often present with a prolonged phase of slow growth but once invasion has occurred, the prognostic features are identical to all other melanomas. These lesions occur primarily on the head and neck where they evolve from areas of pigmented staining to the more typical features identifiable with malignant melanomas on other skin surfaces. The treatment options and recent advances in management are reviewed. J. Surg. Oncol. 2004;86:179–186. © 2004 Wiley‐Liss, Inc.