Lehmann T, Hawley W A, Kamau L, Fontenille D, Simard F, Collins F H
Division of Parasitic Disease, Centers for Disease Control and Prevention, Chamblee, GA 30341, USA.
Heredity (Edinb). 1996 Aug;77 ( Pt 2):192-200. doi: 10.1038/hdy.1996.124.
Genetic variation of Anopheles gambiae was analysed to assess interpopulation divergence over a 6000 km distance using short tandem repeat (microsatellite) loci and allozyme loci. Differentiation of populations from Kenya and Senegal measured by allele length variation at five microsatellite loci was compared with estimates calculated from published data on six allozyme loci (Miles, 1978). The average Wright's FST of microsatellite loci (0.016) was lower than that of allozymes (0.036). Slatkin's RST values for microsatellite loci were generally higher than their FST values, but the average RST value was virtually identical (0.036) to the average allozyme FST. These low estimates of differentiation correspond to an effective migration index (Nm) larger than 3, suggesting that gene flow across the continent is only weakly restricted. Polymorphism of microsatellite loci was significantly higher than that of allozymes, probably because the former experience considerably higher mutation rates. That microsatellite loci did not measure greater interpopulation divergence than allozyme loci suggested constraints on microsatellite evolution. Alternatively, extensive mosquito dispersal, aided by human transportation during the last century, better explains the low differentiation and the similarity of estimates derived from both types of genetic markers.
对冈比亚按蚊的遗传变异进行了分析，以评估在6000公里距离内种群间的分化情况，采用了短串联重复序列（微卫星）位点和等位酶位点。通过五个微卫星位点的等位基因长度变异来测量肯尼亚和塞内加尔种群的分化，并与根据已发表的六个等位酶位点数据（迈尔斯，1978年）计算得出的估计值进行比较。微卫星位点的平均赖特氏FST（0.016）低于等位酶的平均FST（0.036）。微卫星位点的斯莱特金氏RST值通常高于其FST值，但平均RST值实际上与平均等位酶FST相同（0.036）。这些低分化估计值对应的有效迁移指数（Nm）大于3，表明整个大陆的基因流动仅受到微弱限制。微卫星位点的多态性显著高于等位酶，可能是因为前者的突变率要高得多。微卫星位点没有比等位酶位点测量出更大的种群间分化，这表明微卫星进化受到限制。或者，在上个世纪人类运输的帮助下，蚊子的广泛扩散更好地解释了低分化以及两种遗传标记得出的估计值的相似性。
