Pascual M, Schug M D, Aquadro C F
Department of Molecular Biology and Genetics, Cornell University, New York, NY, USA.
Mol Biol Evol. 2000 Aug;17(8):1259-67. doi: 10.1093/oxfordjournals.molbev.a026409.
We isolated 96 dinucleotide repeats with five or more tandemly repeated units from a subgenomic Drosophila subobscura library. The mean repeat unit length of microsatellite clones in D. subobscura is 15, higher than that observed in other Drosophila species. Population variation was assayed in 32-40 chromosomes from Barcelona, Spain, using 18 randomly chosen microsatellite loci. Positive correlation between measures of variation and perfect repeat length measures (mean size, most common, and longest allele) is consistent with a higher mutation rate in loci with longer repeat units. Levels of microsatellite variation measured as variance in repeat number and heterozygosity in D. subobscura were similar to those of Drosophila pseudoobscura and higher than those of Drosophila melanogaster and Drosophila simulans. Our data suggest that higher levels of microsatellite variation, and possibly density, in D. subobscura compared with D. melanogaster are due to both a higher average effective population and a higher intrinsic slippage rate in the former species.
我们从一个亚基因组果蝇库中分离出96个具有五个或更多串联重复单元的二核苷酸重复序列。果蝇亚暗果蝇微卫星克隆的平均重复单元长度为15，高于在其他果蝇物种中观察到的长度。使用18个随机选择的微卫星位点，对来自西班牙巴塞罗那的32 - 40条染色体的群体变异进行了测定。变异测量与完美重复长度测量（平均大小、最常见和最长等位基因）之间的正相关与具有较长重复单元的位点中较高的突变率一致。以重复数方差和杂合度衡量的果蝇亚暗果蝇微卫星变异水平与拟暗果蝇相似，高于黑腹果蝇和拟果蝇。我们的数据表明，与黑腹果蝇相比，果蝇亚暗果蝇中较高水平的微卫星变异以及可能的密度，是由于前者具有更高的平均有效种群数量和更高的内在滑动率。
