COLOR ASSORTATIVE MATING CONTRIBUTES TO SYMPATRIC DIVERGENCE OF NEOTROPICAL CICHLID FISH
COLOR ASSORTATIVE MATING CONTRIBUTES TO SYMPATRIC DIVERGENCE OF NEOTROPICAL CICHLID FISH
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DOI：
10.1111/j.1558-5646.2009.00736.x
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发表时间：
2009-10-01
期刊：
影响因子：
3.3
通讯作者：
Meyer, Axel
中科院分区：
文献类型：
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作者：
Elmer, Kathryn R.;Lehtonen, Topi K.;Meyer, Axel
性选择是否能在没有物理障碍的情况下导致物种形成，目前仍存在激烈的争论。本文利用野外资料和分子生物学方法，对尼加拉瓜锡罗亚火山口湖特有的两种丽鱼的金-正色多态性进行了研究。我们发现在西罗亚省两种两性中都存在显著的颜色分类交配。以西loaensis为研究对象，通过微卫星等位基因频率、配位检验和模型聚类分析表明，金色个体与正常个体在同属群中存在明显的遗传分化（F(ST) = 0.03）。此外，我们发现喜罗湖三种同域生态不同的慈鲷，A. amarillo， A. sagittae和A. xiloaensis （F(ST) = 0.03 ~ 0.19）之间存在遗传差异，并且这些物种与邻近的马那瓜湖的近亲A. citrinellus之间存在明显的遗传隔离。与正常的希洛亚种相比，希洛亚种的金形态在基因上与湖中其他两种米达斯慈鲷更不同。因此，我们已经确定了基于颜色的性隔离，这在种群遗传学和配偶选择中很明显。我们的研究结果表明，通过颜色分类交配的性选择可能在尼加拉瓜迈达斯慈鲷的早期同域物种形成中起重要作用。
It is still debated vigorously whether sexual selection can result in speciation without physical barriers to gene flow. In this study, we used field data and molecular methods to investigate the gold-normal color polymorphism in two endemic cichlid fish species of crater lake Xiloa, Nicaragua. We found significant assortative mating by color in both Amphilophus xiloaensis and A. sagittae. Focusing on A. xiloaensis, microsatellite allele frequencies, an assignment test, and model-based cluster analysis demonstrates significant and clear genetic differentiation (F(ST) = 0.03) between gold and normal individuals in sympatry. In addition, we find genetic differentiation between all three sympatric and ecologically distinct Midas cichlid species of Lake Xiloa, A. amarillo, A. sagittae, and A. xiloaensis (F(ST) = 0.03 - 0.19), and clear genetic isolation of these species from their closest relative (A. citrinellus) in the neighboring great lake Managua. The A. xiloaensis gold morph is genetically more distinct from the lake's other two Midas cichlid species than is A. xiloaensis-normal. Thus, we have identified sexual isolation based on color that is evident in population genetics and mate choice. Our results suggest that sexual selection through color assortative mating may play an important role in incipient sympatric speciation in Midas cichlids of Nicaragua.