Evolutionary Genetics of the Melanocortin‐1 Receptor in Vertebrates
Evolutionary Genetics of the Melanocortin‐1 Receptor in Vertebrates
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DOI：
10.1111/j.1749-6632.2003.tb03194.x
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发表时间：
2003-06
影响因子：
5.2
通讯作者：
N. Mundy;Joanne Kelly;E. Theron;K. Hawkins
中科院分区：
文献类型：
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作者：
N. Mundy;Joanne Kelly;E. Theron;K. Hawkins
摘要：表型适应性变化的分子遗传学基础是进化生物学中的一个重大突出问题。毛色和羽毛颜色的进化变化是在这一领域取得进展的一个很有前途的系统。最值得注意的是，最近关于毛发和羽毛颜色的分子遗传学基础的工作已经确定了几个参与哺乳动物和鸟类进化颜色变化的候选基因。我们研究了这些候选基因之一，黑素皮质素-1受体(MC1R)基因的进化与黑色素在各种灵长类物种中的分布变化的关系，以及在香蕉(Coereba Huang Eola)中的变化，这是鸟类黑色羽毛多态性的典型例子。在灵长类动物中，MC1R编码区在毛色进化中的作用可以在几种情况下被排除，在这些情况下，密切相关的物种具有截然不同的真黑色素和/或真黑色素的分布。然而，对灵长类进化过程中的MC1R序列的重建表明，在几个谱系中的重要功能位点存在突变。最值得注意的是，狮子塔玛林(Leontopithecus)表现出惊人的MC1R进化模式，包括缺失和几个非保守的氨基酸变化。在香蕉中，MC1R中的E92K替换与黑色素病密切相关，这很可能是致病突变。重建香蕉MC1R等位基因的进化表明，黑化是该物种的一个派生特征。这些结果证实了候选基因方法在脊椎动物颜色进化中的应用，并为未来的广泛研究开辟了道路。
Abstract: The molecular genetic basis of adaptive change in phenotype is a major outstanding issue in evolutionary biology. Evolutionary change in coat and plumage color is a promising system for making progress in this field. Most notably, recent work on the molecular genetic basis of hair and feather color has identified several genes which are candidates for involvement in evolutionary color change in mammals and birds. We have investigated the evolution of one of these candidate genes, the melanocortin‐1 receptor (MC1R) gene, in relation to changes in melanin distribution among a wide variety of primate species, and in bananaquits (Coereba flaveola), which are a classic case of melanic plumage polymorphism in birds. In primates, a role of the MC1R coding region in coat color evolution can be ruled out in several cases in which closely related species have drastically different distributions of eumelanin and/or pheomelanin. However, reconstruction of MC1R sequences over primate evolution shows the presence of mutations at important functional sites in several lineages. Most notably, the lion tamarins (Leontopithecus) show a striking pattern of MC1R evolution, including deletions and several nonconservative amino acid changes. In the bananaquit, an E92K substitution in the MC1R is strongly associated with melanism, and this is likely to be the causative mutation. Reconstruction of the evolution of bananaquit MC1R alleles shows that melanism is a derived trait in this species. These results confirm the utility of a candidate gene approach to color evolution in vertebrates and open the way for extensive future research.