State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China.
Mol Biol Evol. 2017 Jan;34(1):88-92. doi: 10.1093/molbev/msw222. Epub 2016 Oct 15.
Molecular basis for mammalian echolocation has been receiving much concerns. Recent findings on the parallel evolution of prestin sequences among echolocating bats and toothed whales suggest that adaptations for high-frequency hearing have occurred during the evolution of echolocation. Here, we report that although the species tree for echolocating bats emitting echolocation calls with frequency modulated (FM) sweeps is paraphyletic, prestin exhibits similar functional changes between FM bats. Site-directed mutagenesis shows that the amino acid 308S in FM bats is responsible for the similar functional changes of prestin We strongly support that the occurrence of serine at position 308 is a case of hemiplasy, caused by incomplete lineage sorting of an ancestral polymorphism. Our study not only reveals sophisticated molecular basis of echolocation in bats, but also calls for caution in the inference of molecular convergence in species experiencing rapid radiation.
哺乳动物回声定位的分子基础一直备受关注。最近关于回声定位蝙蝠和齿鲸中 prestin 序列平行进化的发现表明，高频听觉的适应是在回声定位的进化过程中发生的。在这里，我们报告尽管发出调频（FM）扫频回声的回声定位蝙蝠的物种树是并系的，但 prestin 在 FM 蝙蝠之间表现出相似的功能变化。定点诱变表明，FM 蝙蝠中的 308S 氨基酸负责 prestin 的相似功能变化。我们强烈支持位置 308 的丝氨酸的出现是半同形的情况，这是由于祖先多态性的不完全谱系分选造成的。我们的研究不仅揭示了蝙蝠回声定位的复杂分子基础，而且呼吁在快速辐射的物种中对分子趋同的推断保持谨慎。
