Opsin gene duplication and diversification in the guppy, a model for sexual selection
Opsin gene duplication and diversification in the guppy, a model for sexual selection
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DOI：
10.1098/rspb.2006.3707
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发表时间：
2007-01-07
影响因子：
4.7
通讯作者：
Dreyer, Christine
中科院分区：
文献类型：
--
作者：
Hoffmann, Margarete;Tripathi, Namita;Dreyer, Christine
识别控制适应性特征变异的基因是理解驱动性选择和自然选择的过程的先决条件。孔雀鱼是研究自然选择和性选择的模式生物，雄性颜色和雌性颜色知觉在孔雀鱼的配偶选择中起着重要的作用。我们通过分析编码视觉色素蛋白的基因的基因组和互补DNA序列，研究了已知的颜色感知差异的潜在来源。我们发现，无论是在种群内还是种群间，都存在很高的序列变异性，并且长波敏感(LWS)视蛋白基因的拷贝数增加了。具有非同义变化的等位基因表明不同的光谱调谐特性发生在同一群体中，甚至在同一个体中，非同义替换的高频率证明了作用于这些蛋白质的多样化选择。因此，调节氨基酸的可变性在孔雀鱼的个体和种群中被分割，而在更高分类水平上的LW的可变性形成对比，后者是由于性别选择而进行分化的第二个模式系统。由于视蛋白的可变性与孔雀鱼种群中雄性颜色的极端多态相似，我们认为配偶选择是推动该物种视蛋白和雄性装饰物共同进化的主要因素。
Identification of genes that control variation in adaptive characters is a prerequisite for understanding the processes that drive sexual and natural selection. Male coloration and female colour perception play important roles in mate choice in the guppy ( Poecilia reticulata), a model organism for studies of natural and sexual selection. We examined a potential source for the known variation in colour perception, by analysing genomic and complementary DNA sequences of genes that code for visual pigment proteins. We find high sequence variability, both within and between populations, and expanded copy number for long-wave sensitive ( LWS) opsin genes. Alleles with non-synonymous changes that suggest dissimilar spectral tuning properties occur in the same population and even in the same individual, and the high frequency of non-synonymous substitutions argues for diversifying selection acting on these proteins. Therefore, variability in tuning amino acids is partitioned within individuals and populations of the guppy, in contrast to variability for LWS at higher taxonomic levels in cichlids, a second model system for differentiation owing to sexual selection. Since opsin variability parallels the extreme male colour polymorphism within guppy populations, we suggest that mate choice has been a major factor driving the coevolution of opsins and male ornaments in this species.