Genetic bases of mammalian inner ear evolution: Analysis of the Beta V-Spectrin gene

FRANCISCO PISCIOTTANO; ANA BELÉN ELGOYHEN; FRANCHINI LUCÍA F.

Congreso; XXVI Reunión Anual de la Sociedad Argentina de Investigación en Neurociencia; 2011

Sociedad Argentina de Investigación en Neurociencias

The mammalian inner ear has unique hearing capacities that distinguished it from the hearing organ of other vertebrates.  Our main objective is to study the genetic basis underlying the evolution of the particular functional capacities of the mammalian inner ear. Using maximum likelihood methods we are analyzing the evolution of all inner ear proteins to reveal which of them were shaped by positive selection in the lineage leading to mammals. We hypothesize that proteins showing signatures of positive selection in mammals might have acquired new functional capacities that could underlie the particular capacities of the mammalian inner ear. We found in previous work that the motor protein prestin, a key player in the functional capacities of the mammalian inner ear underwent adaptive evolution in the lineage leading to mammals. Here we report that betaV-spectrin, a cytosqueleton component that interacts with prestin has accompanied such evolutionary trend, showing strong signals of positive selection. Our results suggest that a process of positive selection acting on these two proteins has shaped them to fit a mammalian specific function in the inner ear. The present work continues to delineate the genetic bases underlying the evolution of the inner ear in mammals.