Gene flow between species of Lake Victoria haplochromine fishes
Gene flow between species of Lake Victoria haplochromine fishes
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DOI：
10.1093/molbev/msm138
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发表时间：
2007-09-01
影响因子：
10.7
通讯作者：
Klein, Jan
中科院分区：
文献类型：
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作者：
Samonte, Irene E.;Satta, Yoko;Klein, Jan
东非维多利亚湖 (LV) 的单倍色丽鱼科鱼是适应性辐射的教科书例子——从几个创始谱系中迅速分化出多种形态上可区分的形式。人们普遍认为这些形式构成了十几个属的数百个生殖隔离物种的“群”。然而，直到现在，这种信念还没有受到检验。在这里，我们比较了 6 个不同物种的 10 个单倍体群体中 11 个位点的遗传变异。尽管种群的遗传多样性相当高，但使用各种统计测试，我们没有发现LV单倍体种群之间遗传分化的证据。在遗传距离树上，同一物种的种群与不同物种的种群混合。在分子水平上，这些物种彼此之间无法区分。与两个火山口湖中密切相关的物种的遗传比较表明，LV 内的物种继续交换基因。这些观察结果对系统发育重建具有重要意义。本研究中使用的方法适用于自适应辐射的其他情况。
The haplochromine cichlid fishes of Lake Victoria (LV), East Africa, are a textbook example of adaptive radiation-a rapid divergence of multiple morphologically distinguishable forms from a few founding lineages. The forms are generally believed to constitute a "flock" of several hundred reproductively isolated species in a dozen or so genera. This belief has, until now, not been subjected to a test, however. Here, we compare genetic variation at 11 loci in 10 haplochromine populations of 6 different species. Although the genetic diversity in the populations is quite high, using a variety of statistical tests, we find no evidence of genetic differentiation among the populations of LV haplochromines. On genetic distance trees, populations of the same species intermingle with those of different species. At the molecular level, the species are indistinguishable from one another. Genetic comparisons with closely related species in 2 crater lakes indicate that the species within LV continue exchanging genes. These observations have important implications for phylogenetic reconstruction. The approach used in this study is applicable to other instances of adaptive radiation.