Gene flow and the geographical distribution of a molecular polymorphism in Drosophila pseudoobscura.
Gene flow and the geographical distribution of a molecular polymorphism in Drosophila pseudoobscura.
复制标题
果蝇的基因流和分子多态性的地理分布。
DOI：
10.1093/genetics/98.1.157
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发表时间：
1981
期刊：
影响因子：
3.3
通讯作者：
Prout,T
中科院分区：
文献类型：
--
作者：
Jones,JS;Bryant,SH;Lewontin,RC;Moore,JA;Prout,T
本文讨论了拟暗果蝇（Drosophila pseudobscura）一种酶多态性的地理分布与种群结构的关系。生活在相隔几公里的非常不同的山地和低地栖息地的该物种的加州种群在酯酶等位基因的频率上彼此相似。先前的估计表明，基因流动太过有限，无法解释遗传结构的同质性，因此它必须反映自然选择的某种平衡力量。然而，我们发现，在不利的栖息地的扩散比以前假设的要大得多。隔离种群D.与其他种群相隔15公里的伪暗种面临着大量的移民。这是由该物种的季节性丰度的变化，并在每年的致命等位基因在这样的人口模式。实验扰动孤立的人口在绿洲的遗传结构恢复正常，在一年内，这表明这些人口是短暂的，绿洲是受遥远的移民每年的tenonization。对有标记苍蝇的直接评估表明，它们可以在24小时内在沙漠上空移动至少10公里。这种广泛的基因流动可能有助于解释酯酶等位基因的分布，并与高水平的分子多态性及其在整个D.伪暗
This paper discusses the relation between the geographical distribution of an enzyme polymorphism and population structure inDrosophila pseudoobscura. California populations of this species living in very different montane and lowland habitats separated by several kilometers are similar to each other in the frequency of an esterase allele. Previous estimates suggest that gene flow is too limited to account for this homogeneity of genetic structure, so that it must reflect some balancing force of natural selection. We show, however, that dispersal over unfavorable habitats is much greater than earlier supposed. Isolated populations ofD. pseudoobscuraseparated by 15 km from other populations are subject to large amounts of immigration. This is shown by changes in the seasonal abundance of this species and in the annual pattern of lethal alleles in such populations. The genetic structure of an experimentally perturbed isolated population in an oasis returned to normal within a single year, suggesting that such populations are ephemeral and that the oasis is subject to annual recolonization by distant migrants. Direct assessment of marked flies shows that they can move at least 10 km in 24 hours over a desert. Such extensive gene flow may help explain the distribution of the esterase allele, and is relevant to the high level of molecular polymorphism and its general lack of geographic differentiation throughout the range ofD. pseudoobscura.