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Guowen Cai Shelley A. Cole M. Elizabeth Tejero John M. Proffitt Jeanne H. Freeland‐Graves John Blangero Anthony G. Comuzzie 《Obesity (Silver Spring, Md.)》2004,12(11):1766-1772
Objective: Previous research has suggested a genetic contribution to the development of insulin resistance and obesity. We hypothesized that the same genes influencing insulin resistance might also contribute to the variation in adiposity. Research Methods and Procedures: A total of 601 (200 male, 401 female) adult baboons (Papio hamadryas) from nine families with pedigrees ranging in size from 43 to 121 were used in this study. Plasma insulin, glucose, C‐peptide, and adiponectin were analyzed, and homeostasis model assessment of insulin resistance (HOMA IR) was calculated. Fat biopsies were collected from omental fat tissue, and triglyceride concentration per gram of fat tissue was determined. Body weight and length were measured, and BMI was derived. Univariate and bivariate quantitative genetic analyses were performed using SOLAR. Results: Insulin, glucose, C‐peptide, and adiponectin levels, HOMA IR, triglyceride concentration of fat tissue, body weight, and BMI were all found to be significantly heritable, with heritabilities ranging from 0.15 to 0.80. Positive genetic correlations (rGs) were observed for HOMA IR with C‐peptide (rG = 0.88 ± 0.10, p = 0.01), triglyceride concentration in fat tissue (rG = 0.86 ± 0.33, p = 0.02), weight (rG = 0.50 ± 0.20, p = 0.03), and BMI (rG = 0.64 ± 0.22, p = 0.02). Discussion: These results suggest that a set of genes contributing to insulin resistance also influence general and central adiposity phenotypes. Further genetic research in a larger sample size is needed to identify the common genes that constitute the genetic basis for the development of insulin resistance and obesity. 相似文献
995.
Dirca occidentalis is a rare shrub indigenous to only six counties near the San Francisco Bay in California, United States. We used intersimple sequence repeat (ISSR) markers and automated genotyping to probe 29 colonies of D. occidentalis from four geographically disjunct populations (East Bay, North Bay, Salmon Creek, and Peninsula) and used methods of phylogenetics and population genetics to model variation across the species. Results show that the four disjunct populations are genetically isolated and have undergone divergence. Phylogenetic analyses indicate that the East Bay population was the first to diverge, followed by the North Bay, then the Salmon Creek and Peninsula populations. This order of divergence suggests an intriguing natural history for D. occidentalis that is explained by the dynamic geological and climatic history of the Bay Area. Spatial genetic structure detected for the species suggests an interaction of four factors: limited seed dispersal, clonal regeneration, distances traveled by pollinators, and genetic isolation of the four populations. Genetic diversity within the North Bay and Salmon Creek populations is low, indicating poor ecological fitness and risk of decline. ISSRs resolved phylogeographic structure within D. occidentalis, results unattainable with ITS methods, and the integration of tools of phylogenetics and population biology led to an enhanced understanding of this endemic species. 相似文献
996.
A universal competitive fluorescence polarization activity assay for S-adenosylmethionine utilizing methyltransferases 总被引:1,自引:0,他引:1
A high-throughput, competitive fluorescence polarization immunoassay has been developed for the detection of methyltransferase activity. The assay was designed to detect S-adenosylhomocysteine (AdoHcy), a product of all S-adenosylmethionine (AdoMet)-utilizing methyltransferase reactions. We employed commercially available anti-AdoHcy antibody and fluorescein-AdoHcy conjugate tracer to measure AdoHcy generated as a result of methyltransferase activity. AdoHcy competes with tracer in the antibody/tracer complex. The release of tracer results in a decrease in fluorescence polarization. Under optimized conditions, AdoHcy and AdoMet titrations demonstrated that the antibody had more than a 150-fold preference for binding AdoHcy relative to AdoMet. Mock methyltransferase reactions using both AdoHcy and AdoMet indicated that the assay tolerated 1 to 3 microM AdoMet. The limit of detection was approximately 5 nM (0.15 pmol) AdoHcy in the presence of 3 muM AdoMet. To validate the assay's ability to quantitate methyltransferase activity, the methyltransferase catechol-O-methyltransferase (COMT) and a known selective inhibitor of COMT activity were used in proof-of-principle experiments. A time- and enzyme concentration-dependent decrease in fluorescence polarization was observed in the COMT assay that was developed. The IC(50) value obtained using a selective COMT inhibitor was consistent with previously published data. Thus, this sensitive and homogeneous assay is amenable for screening compounds for inhibitors of methyltransferase activity. 相似文献
997.
NELSON VALDIVIA JARROD D. STEHBENS BJÖRN HERMELINK SEAN D. CONNELL MARKUS MOLIS MARTIN WAHL 《Austral ecology》2008,33(8):951-962
Local dynamics such as resource enhancement (e.g. nutrient supply) and stochastic events of destruction (disturbances that provide new space) are hypothesized to counteractively affect species diversity and composition. We tested the independent and interactive effects of nutrients and disturbance on the development of assemblages of epibiota attached to vertical surfaces in an oligotrophic system. Nutrient concentrations were manipulated at three levels (ambient, medium and high) while disturbance was manipulated by removing biomass at seven frequencies (0×, 2×, 3×, 4×, 5×, 7×, 12×). Nutrient and disturbance regimes had opposing effects on diversity such that species richness increased with resource enhancement (nutrients) and declined with disturbance. These results support the model that increased heterogeneity of distribution of limiting resources allows the coexistence of species with low and high resource requirements. 相似文献
998.
L Zhang M A Williams D B Mendel P A Escarpe X Chen K Y Wang B J Graves G Lawton C U Kim 《Bioorganic & medicinal chemistry letters》1999,9(13):1751-1756
1,4,5,6-Tetrahydropyridazine derivative 15 and its C-5 epimer 19, which possessed side chains similar to GS4071, were synthesized via a hetero Diels-Alder reaction, and evaluated as influenza neuraminidase inhibitors. Compounds 15 and 19 exhibited a microM range of influenza neuraminidase inhibitory activity. 相似文献
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Ritchie MG Webb SA Graves JA Magurran AE Macias Garcia C 《Journal of evolutionary biology》2005,18(4):922-929
Currently there is much interest in the potential for sexual selection or conflict to drive speciation. Theory proposes that speciation will be accelerated where sexual conflict is strong, particularly if females are ahead because mate choice will accentuate divergence by limiting gene flow. The Goodeinae are a monophyletic group of endemic Mexican fishes with an origin at least as old as the Miocene. Sexual selection is important in the Goodeinae and there is substantial interspecific variability in body morphology, which influences mate choice, allowing inference of the importance of female mate choice. We therefore used this group to test the relationship between sexual dimorphism and speciation rate. We quantified interspecific variation in sexual dimorphism amongst 25 species using a multivariate measure of total morphological differentiation between the sexes that accurately reflects sexual dimorphism driven by female mate choice and also used a mtDNA-based phylogeny to examine speciation rates. Comparative analyses failed to support a significant association between sexual dimorphism and speciation rate. In addition, variation in the time course of speciation throughout the whole clade was also examined using a similar tree containing 34 extant species. A constant rates model for the growth of this clade was rejected, but analyses instead indicated a decline in the rate of speciation over time. These results support the hypothesis of an early expansion of the group, perhaps due to an early radiation influenced by the key innovation of live bearing, or the prevalence of Miocene volcanism. In general, support for the role of sexual selection in generating patterns of speciation is proving equivocal and we argue that vicariance biogeography and adaptive radiations remain the most likely determinants of major patterns of diversification of continental organisms. 相似文献