Evolution of Human Tissue-Specific Genes. Rates, Expression, and Interactions

ARBIZA L, AN DH DOPAZO

Barcelona. Spain

Congreso; Annual Meeting of the Society of Molecular Biology and Evoltion; 2008

Society for molecular biology and evolution

Evolution of Human Tissue-Specific Genes. Rates, Expression, and Interactions Leonardo Arbiza, & Hernan Dopazo Comparative Genomics. Bioinformatics, Centro Invest. Principe Felipe, Valencia, España Contact E-mail: larbiza@cipf.es Several recent studies have reached different conclusions regarding positive selection on brain specific genes along the evolutionary lineage leading to modern humans. To solve this apparent disparity, we present a re-analysis of genomic data from human, chimpanzee, mouse, and rat, in addition to other previously published data sets using maximum likelihood methods and methods for measuring and combining estimates of dN/dS. Additional factors, such as interactions, expression level, and expression breadth data associated to brain and other tissue specific genes are also examined. Methods used to combine dN/dS estimates influence conclusions regarding comparisons of rates of evolution among different categories of genes. We find a consistent lack of evidence for a higher dN/dS ratio in human brain specific genes. Brain is in fact the category with the lowest rates while the highest rates belong to liver, pancreas, and prostate or testis specific genes. Moreover, we found that many tissue-specific genes including those of brain show lower number of interactions than the observed for the mean value of the human genome. Finally, branch-site tests on tissue-specific genes do not show more evidence for positive selection in the human than in the chimpanzee lineage. Created/modified on 26/02/2008 16:32