Adaptive Evolution Of The Cochlear Morphology Genes In Owls

Strigiformes are relatively special groups of birds,and most of them hunt and act at night.Due to long-term adaptation to the dark environment,their hearing becomes very acute.Some studies have demonstrated that they can only rely on auditory to locate and prey in totally dark environment,most studies on owls' hearing mainly focus on the behavior,physiology and anatomy,almost no study is offered to determine the molecular basis of their enhanced hearing.In this study,we conducted comparatively evolutionary analysis of the cochlea morphogensis genes between owls and their diurnal relatives based on the cochlea tissue transcriptome sequencing.Thirty-five genes related to the morphogenesis of cochlea were analyzed and six positively selected genes CDH23,PCDH15,MYO6,MYO7 A,PROX1,and PDZD7 along the ancestral owl branch were found.CDH23,MYO7 A,and PROX1 play an important role in maintaining the normal morphology and function of hair cells.PCDH15 and PDZD7 play a significant role in maintaining the sensitivity of hair cells.The gene MYO6 plays an important role in maintaining the stability of the structure of hair cells.These positively selected hearing genes may underlie the enhanced hearing capability in owls.