The population genetics of the origin and divergence of the Drosophila simulans complex species.
The population genetics of the origin and divergence of the Drosophila simulans complex species.
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发表时间：
2000-12
期刊：
影响因子：
3.3
通讯作者：
R. Kliman;P. Andolfatto;J. Coyne;F. Depaulis;M. Kreitman;A. Berry;J. McCarter;J. Wakeley;J. H
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文献类型：
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作者：
R. Kliman;P. Andolfatto;J. Coyne;F. Depaulis;M. Kreitman;A. Berry;J. McCarter;J. Wakeley;J. H
拟果蝇及其近缘种D. mauritiana和D.使用在14个不同基因处发现的物种内和物种之间的DNA序列变异模式对sechellia进行了检查。D. sechellia一致揭示低水平的多态性，和来自D. sechellia的累积突变率比D. simulans。在同义位点，D. Sechellia经历了显著过量的非优选密码子置换。这些结果表明D.一段时间以来，sechellia的有效种群规模一直在减少，因此正在积累轻微的有害突变。D. simulans和D.毛里求斯都是高度多态性和两个物种共享许多多态性，可能是因为时间的共同祖先。一个简单的隔离物种形成模型，与零基因流以下的初期物种分离，拟合到simulans/毛里求斯分歧和simulans/sechellia分歧。在这两种情况下，模型都很好地拟合了数据，分析显示物种之间的基因流动几乎没有证据。例外的是在D中的一个基因座上的一个基因拷贝。sechellia与其它D.模拟序列总体情况是两个异地物种形成事件，发生在彼此非常接近的时间。
The origins and divergence of Drosophila simulans and close relatives D. mauritiana and D. sechellia were examined using the patterns of DNA sequence variation found within and between species at 14 different genes. D. sechellia consistently revealed low levels of polymorphism, and genes from D. sechellia have accumulated mutations at a rate that is approximately 50% higher than the same genes from D. simulans. At synonymous sites, D. sechellia has experienced a significant excess of unpreferred codon substitutions. Together these observations suggest that D. sechellia has had a reduced effective population size for some time, and that it is accumulating slightly deleterious mutations as a result. D. simulans and D. mauritiana are both highly polymorphic and the two species share many polymorphisms, probably since the time of common ancestry. A simple isolation speciation model, with zero gene flow following incipient species separation, was fitted to both the simulans/mauritiana divergence and the simulans/sechellia divergence. In both cases the model fit the data quite well, and the analyses revealed little evidence of gene flow between the species. The exception is one gene copy at one locus in D. sechellia, which closely resembled other D. simulans sequences. The overall picture is of two allopatric speciation events that occurred quite near one another in time.