Adaptive evolution of a candidate gene for aging in Drosophila.
Adaptive evolution of a candidate gene for aging in Drosophila.
复制标题
果蝇衰老候选基因的适应性进化。
DOI：
10.1073/pnas.190338897
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发表时间：
2000
影响因子：
11.1
通讯作者：
Eanes,WF
中科院分区：
文献类型：
--
作者：
Schmidt,PS;Duvernell,DD;Eanes,WF
对特定突变的表型效应的检查已被广泛用于鉴定影响感兴趣性状的候选基因。然而，这样的分析并没有揭示任何关于作用于这些位点的进化力量，或者是否存在等位基因变异有助于自然群体中的表型变异。 果蝇基因组（mth）被认为对机体的应激反应和寿命表型有重要影响。在这里，我们研究了果蝇（Drosophilamelanogaster）、黑腹果蝇（D. simulans和D.日本料理。Mthhas经历了异常高水平的适应性氨基酸趋异，集中在受体蛋白的内环和细胞外环结构域，这表明正选择对调节信号转导的分子区域的历史作用。对黑腹果蝇单核苷酸多态性（SNPs）的进一步分析为该基因座的当代选择和空间选择提供了证据。在10个被调查的群体中，最常见的mthhaplotype表现出40%的频率渐变，这与包括寿命在内的多个生活史性状的群体水平差异相吻合。这种倾斜模式与编码区中的任何特定SNP无关，表明选择是在可能参与基因表达的紧密连锁位点上进行的。总之，这些一致的非中性模式的种间和种内的变化表明适应性进化的信号转导途径，可以调节寿命的性质。
Examination of the phenotypic effects of specific mutations has been extensively used to identify candidate genes affecting traits of interest. However, such analyses do not reveal anything about the evolutionary forces acting at these loci, or whether standing allelic variation contributes to phenotypic variance in natural populations. TheDrosophilagenemethuselah(mth) has been proposed as having major effects on organismal stress response and longevity phenotype. Here, we examine patterns of polymorphism and divergence atmthin population level samples ofDrosophila melanogaster,D. simulans, andD. yakuba. Mthhas experienced an unusually high level of adaptive amino acid divergence concentrated in the intra- and extracellular loop domains of the receptor protein, suggesting the historical action of positive selection on those regions of the molecule that modulate signal transduction. Further analysis of single nucleotide polymorphisms (SNPs) inD. melanogasterprovided evidence for contemporary and spatially variable selection at themthlocus. In ten surveyed populations, the most commonmthhaplotype exhibited a 40% cline in frequency that coincided with population level differences in multiple life-history traits including lifespan. This clinal pattern was not associated with any particular SNP in the coding region, indicating that selection is operating at a closely linked site that may be involved in gene expression. Together, these consistently nonneutral patterns of inter- and intraspecific variation suggest adaptive evolution of a signal transduction pathway that may modulate lifespan in nature.