Abstract
The hearing is one of the interesting senses to see the evolutionary divergence of mammals since mammalian auditory system is known to have a wide variety of sensing ability such as hearing ranges and thresholds. Thus, we examine the divergence of auditory system as a key to understand the mammalian evolution. To attain our purpose, we first conducted the comparative and evolutionary analyses based on 71 genes. These genes are known to be responsible for the human nonsyndromic deafness, and thus they are strongly linked to the hearing function. The comparative study of these genes showed that more than 79% of genes were commonly shared among mammals. We also found the genes evolved fast on the lineage toward placental which have the most diverged hearing functions. Interestingly, those genes also expressed specifically on the outer hair cells, suggesting their importance in the evolution of the auditory system. Based on our findings, we will discuss an evolutionary process of the auditory system and a mammalian evolution.