Initial mutational steps toward loss of opsin gene function in cavefish.
Initial mutational steps toward loss of opsin gene function in cavefish.
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DOI：
10.1093/oxfordjournals.molbev.a040233
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发表时间：
1995-07
影响因子：
10.7
通讯作者：
S. Yokoyama;A. Meany;H. Wilkens;R. Yokoyama
中科院分区：
文献类型：
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作者：
S. Yokoyama;A. Meany;H. Wilkens;R. Yokoyama
采集了墨西哥Pachon和Micos洞穴的河栖鱼类Astyanax fasciatus及其衍生物。通过比较三个种群的红色（r 007）和绿色（g103）视蛋白基因序列，我们发现有眼米科鱼r 007和g103中C-->T的变化频率很高，推测是由于自发的胞嘧啶甲基化或CG二核苷酸的酶促脱氨基作用，而盲帕琼鱼g101中有12个连续核苷酸的缺失。因此，通常在假基因中发现的高比率的核苷酸替换和C->T转换甚至可能在它们变得无功能之前发生。
The river-dwelling fishes of Astyanax fasciatus and their derivatives from Pachon and Micos caves in Mexico were collected. By comparing red (r007) and green (g103) opsin gene sequences from the three populations, we found a high frequency of C-->T changes in r007 and g103 of the eyed Micos fishes presumably due to spontaneous cytosine methylation or enzymatic deamination of the CG dinucleotide, and a deletion of 12 consecutive nucleotides in g101 of the blind Pachon fishes. Thus, high rates of nucleotide substitution and C-->T transitions, usually found for pseudogenes, may occur even before they become nonfunctional.