Avian Comparative Genomics Facilities the Seek for Candidate Genes Involved in Complex Behaviors

Modern birds are characterized by diversity of morphologies, habitats as well as behaviors. Ecologists have long been observing and recording the various behaviors of birds in wild. However, few behavioral traits have been explained in the genetic level. Here we utilized the whole genomes of 48 avian species to conduct the comparative analysis on the coding genes as well as the non-coding regions. Among 48 birds, there are 6 vocal learners, 10 cooperative breeders, 6 predators and 18 waterbirds. dN/dS analysis was performed to identify fast evolving genes in the 4 categories of behaviors respectively. We found 42, 46, 225 and 107 genes are fast evolving in vocal learners, cooperative breeders, predators and waterbirds respectively, which have probably undergone adaptive evolution. We also sought to detect lineage-specific conserved or accelerated genomic elements which may harbor the regulatory sequences of the behavior-related genes. A substantial number of conserved elements are found located in the promoters or intronic regions which are possibly the regulatory sequences for the candidate genes involved in the behaviors such as vocal learning. Comparative genomics in this study demonstrates its high potential in studying the genetic basis of complex behaviors.