Genetic variation and differentiation at microsatellite loci in Drosophila simulans. Evidence for founder effects in new world populations.
Genetic variation and differentiation at microsatellite loci in Drosophila simulans. Evidence for founder effects in new world populations.
复制标题
模拟果蝇微卫星位点的遗传变异和分化。
DOI：
10.1093/genetics/150.2.777
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发表时间：
1998
期刊：
影响因子：
3.3
通讯作者：
Aquadro,CF
中科院分区：
文献类型：
--
作者：
Irvin,SD;Wetterstrand,KA;Hutter,CM;Aquadro,CF
对来自非洲、南美和北美两个地区的模拟果蝇等雌系在X、2、3号染色体上的16个微卫星座位和18个尚未定位的微卫星上进行了变异调查。拟人猿被认为是最近才在新大陆的栖息地定居的(在过去的几百年内)。与殖民者进入这些新大陆栖息地时发生的创始人效应一致，我们发现北美和南美的仿生石斑菌种群的微卫星变异性低于非洲种群。在微卫星上测量的种群分化在所有座位上的平均水平是适度的(fst=0.136)，但与之前关于等位酶变异的研究形成了鲜明的对比，这些研究表明，在拟南山毛虫中的分化明显低于在黑腹毛虫中的分化。在新大陆种群中观察到的独有等位基因比在黑腹毛虫的类似调查中观察到的要少得多。除了在进化历史上可能存在的种群大小差异外，可能需要不同的殖民史或其他人口统计事件来解释在这些密切相关的物种之间观察到的各种遗传标记变异模式的差异。
Drosophila simulans isofemale lines from Africa, South America, and two locations in North America were surveyed for variation at 16 microsatellite loci on the X, second, and third chromosomes, and 18 microsatellites, which are unmapped. D. simulans is thought to have colonized New World habitats only relatively recently (within the last few hundred years). Consistent with a founder effect occurring as colonizers moved into these New World habitats, we find less microsatellite variability in North and South American D. simulans populations than for an African population. Population subdivision as measured at microsatellites is moderate when averaged across all loci (FST= 0.136), but contrasts sharply with previous studies of allozyme variation, which have showed significantly less differentiation in D. simulans than in D. melanogaster. There are substantially fewer private alleles observed in New World populations of D. simulans than seen in a similar survey of D. melanogaster. In addition to possible differences in population size during their evolutionary histories, varying colonization histories or other demographic events may be necessary to explain discrepancies in the patterns of variation observed at various genetic markers between these closely related species.