Hilton H, Hey J
Department of Biological Sciences, Rutgers University, Piscataway, NJ 08855-1059, USA.
Genetics. 1996 Nov;144(3):1015-25. doi: 10.1093/genetics/144.3.1015.
The virilis phylad of the Drosophila virilis group consists of five closely related taxa: D. virilis, D. lummei, D. novamexicana, D. americana americana and D. americana texana. DNA sequences from a 2.1-kb pair portion of the period locus were generated in four to eight individuals from each of the five taxa. We found evidence of recombination and high levels of variation within species. We found no evidence of recent natural selection. Surprisingly there was no evidence of divergence between D. a. americana and D. a. texana, and they collectively appear to have had a large historical effective population size. The ranges of these two taxa overlap in a large hybrid zone that has been delineated in the eastern U.S. on the basis of the geographic pattern of a chromosomal fusion. Also surprisingly, D. novamexicana appears to consist of two distinct groups each with low population size and no gene flow between them.
粗壮果蝇、卢氏果蝇、新墨西哥果蝇、美洲果蝇指名亚种和美洲果蝇得克萨斯亚种。从这五个分类单元的每一个中选取四到八只个体，生成了周期基因座2.1千碱基对部分的DNA序列。我们发现了物种内重组和高变异水平的证据。我们没有发现近期自然选择的证据。令人惊讶的是，没有证据表明美洲果蝇指名亚种和美洲果蝇得克萨斯亚种之间存在分化，而且它们共同的历史有效种群规模似乎很大。这两个分类单元的分布范围在美国东部一个大的杂交区域重叠，该区域是根据染色体融合的地理模式划定的。同样令人惊讶的是，新墨西哥果蝇似乎由两个不同的群体组成，每个群体的种群规模都很小，且它们之间没有基因流动。
