Comparative Genomics in Birds

摘要: The evolution of birds from theropod dinosaurs took place approximately 150 million years ago, and was associated with a number specific adaptations that are still evident among extant birds, including feathers, song extravagant secondary sexual characteristics. Knowledge about the molecular evolutionary background to such is lacking. Here, we analyse > 5000 protein-coding gene sequences expressed in zebra finch brain by comparison orthologous chicken. Mean d(N)/d(S) 0.085 genes their maximal expression eye central nervous system have lowest mean value, while those digestive reproductive tissues exhibit highest. We find fast-evolving (those which higher than expected rate nonsynonymous substitution, indicative adaptive evolution) enriched for biological functions as fertilization, muscle contraction, defence response, response stress, wounding endogenous stimulus, cell death. After alignment mammalian orthologues, identify catalogue 228 show significantly protein two bird lineages mammals. These accelerated genes, representing candidates avian-specific adaptations, include implicated vocal learning other cognitive processes. Moreover, colouration evolve faster mammals, may been driven selection plumage