Neafsey Daniel E, Hartl Daniel L
Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA.
Gene. 2005 May 9;350(2):161-71. doi: 10.1016/j.gene.2005.02.011. Epub 2005 Apr 7.
We describe the complete opsin gene families from the sequenced fugu and Tetraodon pufferfish genomes. We report the convergent loss of function of an anciently duplicated, functionally divergent RH2 or "green-sensitive" opsin gene in both pufferfish lineages, designated RH2-2. In fugu, RH2-2 apparently ceased to function very recently following a transposon-induced deletion that truncated the N-terminal 115 amino acids from the translated protein. Although a lack of frameshift or nonsense mutations in the fugu RH2-2 pseudogene suggests that the gene was lost very recently in this lineage, we were unable to detect any evidence of a selective sweep associated with the fixation of the truncated allele from population data. Interspecific comparison of the remaining fugu RH2-2 coding sequence paradoxically indicates that the gene was under strong purifying selection until the truncation occurred.
我们描述了来自已测序的河豚和红鳍东方鲀河豚基因组的完整视蛋白基因家族。我们报告了在两个河豚谱系中一个古老复制、功能分化的RH2或“绿色敏感”视蛋白基因（命名为RH2-2）的功能趋同丧失。在河豚中，RH2-2显然在最近因转座子诱导的缺失而停止功能，该缺失从翻译的蛋白质中截短了N端的115个氨基酸。尽管河豚RH2-2假基因中缺乏移码或无义突变表明该基因在这个谱系中是最近才丢失的，但我们无法从群体数据中检测到与截短等位基因固定相关的任何选择性清除的证据。剩余河豚RH2-2编码序列的种间比较却表明，在截短发生之前该基因一直受到强烈的纯化选择。
