Department of Ecology and Evolutionary Biology, University of California, Los Angeles, United States.
School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.
Elife. 2018 Dec 18;7:e37412. doi: 10.7554/eLife.37412.
The loss of previously adaptive traits is typically linked to relaxation in selection, yet the molecular steps leading to such repeated losses are rarely known. Molecular studies of loss have tended to focus on gene sequences alone, but overlooking other aspects of protein expression might underestimate phenotypic diversity. Insights based almost solely on opsin gene evolution, for instance, have made mammalian color vision a textbook example of phenotypic loss. We address this gap by investigating retention and loss of opsin genes, transcripts, and proteins across ecologically diverse noctilionoid bats. We find multiple, independent losses of short-wave-sensitive opsins. Mismatches between putatively functional DNA sequences, mRNA transcripts, and proteins implicate transcriptional and post-transcriptional processes in the ongoing loss of S-opsins in some noctilionoid bats. Our results provide a snapshot of evolution in progress during phenotypic trait loss, and suggest vertebrate visual phenotypes cannot always be predicted from genotypes alone.
先前适应性状的丧失通常与选择的放松有关，但导致这种重复丧失的分子步骤却鲜为人知。对丧失的分子研究往往只关注基因序列，但忽略蛋白质表达的其他方面可能会低估表型多样性。几乎仅基于视蛋白基因进化的观点，使哺乳动物的颜色视觉成为表型丧失的典型例子。我们通过研究不同生态环境的夜翼蝙蝠的视蛋白基因、转录本和蛋白质的保留和丧失来解决这一差距。我们发现了多个独立的短波敏感视蛋白的丧失。假定功能 DNA 序列、mRNA 转录本和蛋白质之间的不匹配表明，在一些夜翼蝙蝠中，S-视蛋白的持续丧失涉及转录和转录后过程。我们的研究结果提供了在表型性状丧失过程中进化的一个快照，并表明脊椎动物的视觉表型不能仅从基因型来预测。
