凹耳臭蛙和大绿臭蛙高频听觉敏感基因的分子进化模式研究

Acoustic communication is essential for survival, reproduction and evolution of anurans. Masking background noise is a critical factor for effective acoustic communication, and previous analyses have suggested that males of the concave-eared frog (Odorrana tormota) and Odorrana graminea could produce and detect ultrasounds for the purpose of adaptation to the intense, predominately low-frequency ambient noise produced by nearby streams and waterfalls, whether females of both species exhibit no ultrasonic sensitivity. However, the molecular basis underlying the evolution of ultrasonic hearing and the auditory sex differences in these two odor frogs is poorly documented to date. Here, two high-frequency hearing-sensitive genes, i.e., prestin and KCNQ4, from these two odor frogs as well as other representative amphibians were determined and compared by evolutionary genetics and bioinformatics analysis. The aims of this project were 1) to determine the evolutionary patterns and driving force of prestin and KCNQ4 genes in anurans during their adaptation and diversification, and 2) to reveal the molecular genetic mechanism for ultrasonic hearing adaptation and sex differences in Odorrana tormota and Odorrana graminea, and 3) to provide new insights into the evolutionary process and molecular basis for the adaptation of auditory system of terrestrial vertebrates to various terrestrial environments.

声通讯对无尾两栖类的生存、繁衍和进化具有重要意义。环境中的噪音会严重影响动物的声通讯，已有研究显示，在以低频为主的强环境噪音中，雄性凹耳臭蛙和大绿臭蛙通过发出并接收含有超声组分的鸣叫适应山涧激流生活，而雌性则不能接收其中的超声部分。然而，关于两种臭蛙适应溪流生境进化超声听觉以及高频听觉性二态性的分子机制尚不清楚。本项目拟通过两种臭蛙及其他不同生活类型无尾两栖类高频听觉敏感基因prestin和KCNQ4的克隆及其进化遗传学和生物信息学分析，揭示无尾两栖类在起源和分化过程中prestin和KCNQ4基因的进化模式和驱动因素，探讨凹耳臭蛙和大绿臭蛙超声听觉适应及高频听觉的性别差异的分子遗传学机制，为陆生脊椎动物听觉系统对陆生生境适应性进化的过程和机制提供科学依据。