Identification Of Genes Responsible For The Convergent Courtship Feeding Behavior In Avian At Sequence Level

Convergent evolution refers to the independent evolution of similar features among species to adapt to similar environment or fill in the same niche.The evolution of similar phenotypic features among species living in similar environmental context has long been seen as evidence of adaptability.Studies on convergent evolution generally relate selection pressure with phenotypes.Birds' courtship behavior is a complex behavior,including singing,feather,etc.,but some species which are far away from each other in the phylogeny tend to show similar courtship behavior.The molecular mechanism behind this phenotypic convergence remains to be studied.In this study,nine avian species were selected with goal to identify candidate genes related to birds' courtship-feeding behavior from the perspectives of gene family dynamics and direct homology,which helps to explain the mystery of bird courtship feeding behavior,provides a reference for studying the courtship behavior of other species.From the perspective of gene family analysis,it is found that: 1)in most cases,the gene family of birds is dominated by single copy,and the gene families in most bird species are largely contracted during the process of evolution.2)the rate of genetic gain and loss of avian gene family is very low,indicating that birds are subject to strong functional constraints during the evolution process of millions of years.3)feeding-courtship behavior of birds is likely related to the expansion and contraction of specific gene families,such as gene family of DNM1,which has putative functions related to stimulus response behavior,whereas the function of contracted gene families are mostly related to cell process and cell composition.In terms of homologous genes,the genes containing convergent amino acid sites were first identified,then positive selection analysis were combined.In courtship-feeding birds,most genes contained convergent amino acid sites were related to animal behaviors,such as ADORA2 A gene,which was related to feeding and foraging behaviors.Furthermore,some genes related to reproductive behavior,mating behavior and feeding behavior have experienced accelerated evolution,while those related to reproductive process,immune function and stimulation response have experienced positive selection.Focused on the fourteen genes that contained both the convergence locus and accelerated evolution in courtship feeding birds,and it was found that the function of most genes were related to the development of the central nervous system,the regionalization of the telencephalon,the development of the embryonic brain,and some were related to animal behavior.On the other hand,Functional annotation was conducted on four genes that contained both the convergence locus and positive selection.Consequently,these genes were related to the regulation of cell mitosis and the activity of protein kinase.