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Pleiotropic Genes (pleiotropic + gene)
Selected AbstractsEvidence for a female-specific effect of a chromosome 4 locus on anxiety-related behaviors and ethanol drinking in ratsGENES, BRAIN AND BEHAVIOR, Issue 6 2006L. F. Vendruscolo Previous studies using the inbred rat strains Lewis (LEW) and spontaneously hypertensive rats (SHR) led to the mapping of two quantitative trait loci, named Ofil1 (on chromosome 4 of the rat) and Ofil2 (on chromosome 7), for open-field inner locomotion, a behavioral index of anxiety. Studies using other strains showed that the region next to Ofil1 influences measures of not only anxiety but also ethanol consumption. In view of the high prevalence of psychiatric disorders such as anxiety and alcoholism, as well as the comorbidity between them, the present study was designed to better characterize the contribution of these two loci to complex emotional and consummatory responses. Rats deriving from an F2 intercross between the LEW and the SHR strains were selected according to their genotype at markers flanking the loci Ofil1 and Ofil2 and bred to obtain lines of rats homozygous LEW/LEW or SHR/SHR for each of the two loci, thus generating four genotypic combinations. These selected animals as well as purebred LEW and SHR rats of both sexes were submitted to a battery of tests including measures of locomotor activity, anxiety, sweet and bitter taste reinforcement and ethanol intake. Lewis rats displayed more anxiety-like behavior and less ethanol intake than SHR rats. Ofil1 (on chromosome 4) affected both the activity in the center of the open field and ethanol drinking in females only. These results suggest that Ofil1 contains either linked genes with independent influences on anxiety-related responses and ethanol drinking or a pleiotropic gene with simultaneous effects on both traits. [source] Univariate and Bivariate Linkage Analysis Identifies Pleiotropic Loci Underlying Lipid Levels and Type 2 Diabetes RiskANNALS OF HUMAN GENETICS, Issue 4 2010Sandra J. Hasstedt Summary Dyslipidemia frequently co-occurs with type 2 diabetes (T2D) and with obesity. To investigate whether the co-occurrence is due to pleiotropic genes, we performed univariate linkage analysis of lipid levels and bivariate linkage analysis of pairs of lipid levels and of lipid levels paired with T2D, body mass index (BMI), and waist-hip ratio (WHR) in the African American subset of the Genetics of NIDDM (GENNID) sample. We obtained significant evidence for a pleiotropic low density lipoprotein cholesterol (LDL-C),T2D locus on chromosome 1 at 16,19 megabases (MB) (bivariate lod = 4.41), as well as a non-pleiotropic triglyceride (TG) locus on chromosome 20 at 28,34 MB (univariate lod = 3.57). In addition, near-significant evidence supported TG,T2D loci on chromosome 2 at 81,101 MB (bivariate lod = 4.23) and 232,239 MB (bivariate lod = 4.27) and on chromosome 7 at 147,151 MB (univariate lod = 3.08 for TG with P = 0.041 supporting pleiotropy with T2D), as well as an LDL-C,BMI locus on chromosome 3 at 137,147 MB (bivariate lod score = 4.25). These findings provide evidence that at least some of the co-occurrence of dyslipidemia with T2D and obesity is due to common underlying genes. [source] Logistic Regression Models for Polymorphic and Antagonistic Pleiotropic Gene Action on Human Aging and LongevityANNALS OF HUMAN GENETICS, Issue 6 2003Qihua Tan Summary In this paper, we apply logistic regression models to measure genetic association with human survival for highly polymorphic and pleiotropic genes. By modelling genotype frequency as a function of age, we introduce a logistic regression model with polytomous responses to handle the polymorphic situation. Genotype and allele-based parameterization can be used to investigate the modes of gene action and to reduce the number of parameters, so that the power is increased while the amount of multiple testing minimized. A binomial logistic regression model with fractional polynomials is used to capture the age-dependent or antagonistic pleiotropic effects. The models are applied to HFE genotype data to assess the effects on human longevity by different alleles and to detect if an age-dependent effect exists. Application has shown that these methods can serve as useful tools in searching for important gene variations that contribute to human aging and longevity. [source] Quantitative genetic parameters for growth-related and morphometric traits of hatchery-produced Japanese flounder Paralichthys olivaceus in the wildAQUACULTURE RESEARCH, Issue 12 2007Takahito Shikano Abstract To understand quantitative genetic characteristics of hatchery-produced Japanese flounder in the wild, heritability and genetic correlation of growth-related and morphometric traits were examined in yearling released individuals at a coastal region in northeast Japan. Quantitative genetic parameters were estimated with restricted maximum likelihood following reconstruction of pedigree by a likelihood method using seven microsatellite loci. Estimates of heritability were 0.65 and 0.51 for growth-related traits (body length and the proportion of body length to body depth) and 0.45,0.62 for morphometric traits (vertebral count and dorsal and anal fin ray counts). Genetic correlation was significantly positive (0.61) between dorsal and anal fin ray counts, indicating the possibility of pleiotropic genes or gametic phase disequilibrium for these traits. All the estimates of heritability and genetic correlation in the released individuals were close to those of hatchery-reared juveniles, suggesting that yearling released individuals had similar quantitative genetic characteristics of growth and morphometric traits in the wild to hatchery-reared juveniles. [source] | ||||||||||