Divergent enhancer haplotype of ebony on inversion In(3R)Payne associated with pigmentation variation in a tropical population of Drosophila melanogaster
Divergent enhancer haplotype of ebony on inversion In(3R)Payne associated with pigmentation variation in a tropical population of Drosophila melanogaster
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DOI：
10.1111/j.1365-294x.2011.05260.x
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发表时间：
2011-10-01
影响因子：
4.9
通讯作者：
Takano-Shimizu, Toshiyuki
中科院分区：
文献类型：
--
作者：
Takahashi, Aya;Takano-Shimizu, Toshiyuki
色素沉着的模式和强度通过各种生态因子直接影响个体适合度。在来自日本南部的果蝇种群中，大多数品系的胸三叉戟色素沉着强度可分为暗型或亮型。乌木基因的表达水平的变化与这种表型和等位基因的表达差异表明，部分是由于顺式调节的变化。在13kb左右的基因区域中，我们发现了17个核苷酸位点和2个indel，它们与胸三叉戟色素沉着强度完全相关。有趣的是，19个位点中有11个位于核心表皮增强子的0.5 kb以内。这些位点与先前分析的来自乌干达和肯尼亚的非洲人群的腹部色素沉着强度没有明显的关联，这表明单个基因顺式调控区的多个潜在突变途径可能导致该物种内类似的表型变异。我们还发现，轻型增强子单倍型是强烈联系到一个世界性的倒位，在（3R）佩恩，这是在两个半球的温暖气候地区占主导地位。序列模式表明，强烈的联系可能是由于热适应相关的选择力。推断的选择较轻的色素沉着在日本人口是在相反的方向，以前报道的情况下，选择较暗的个人在非洲人口。然而，这两种适应性变化都涉及乌木的顺式调节变化，这表明该基因可能是自然选择的共同目标。
The pattern and intensity of pigmentation have direct impact on individual fitness through various ecological factors. In a Drosophila melanogaster population from southern Japan, thoracic trident pigmentation intensity of most of the strains could be classified into Dark or Light-type. The expression level variation of the ebony gene correlated well with this phenotype and the allelic differences in expression indicated that the variation is partly due to cis-regulatory changes. In the similar to 13 kb gene region, we identified 17 nucleotide sites and 2 indels that were in complete association with the thoracic trident pigmentation intensity. Interestingly, 11 out of 19 sites located within similar to 0.5 kb of the core epidermis enhancer. These sites had no obvious association with the abdominal pigmentation intensity in the previously analysed African populations from Uganda and Kenya, which suggested that multiple potential mutational pathways in the cis-regulatory control region of a single gene could lead to similar phenotypic variation within this species. We also found that the Light-type enhancer haplotype is strongly linked to a cosmopolitan inversion, In(3R)Payne, which is predominant in warmer climatic regions in both hemispheres. The sequence pattern suggested that the strong linkage may be due to selective forces related to thermal adaptation. The inferred selection for lighter pigmentation in the Japanese population is in the opposite direction of the previously reported case of selection for darker individuals in African populations. Nevertheless, both adaptive changes involved cis-regulatory changes of ebony, which shows that this gene is likely to be a common target of natural selection.