REPRODUCTIVE ISOLATION AND LOCAL ADAPTATION QUANTIFIED FOR A CHROMOSOME INVERSION IN A MALARIA MOSQUITO
REPRODUCTIVE ISOLATION AND LOCAL ADAPTATION QUANTIFIED FOR A CHROMOSOME INVERSION IN A MALARIA MOSQUITO
复制标题
DOI：
10.1111/j.1558-5646.2012.01836.x
复制
发表时间：
2013-04-01
期刊：
影响因子：
3.3
通讯作者：
Kirkpatrick, Mark
中科院分区：
文献类型：
--
作者：
Ayala, Diego;Guerrero, Rafael F.;Kirkpatrick, Mark
长期以来，染色体倒位被认为与物种形成和局部适应有关。然而，关于倒位多态性对生殖隔离和生存能力的影响，我们几乎没有定量的信息。在这里，我们提供了第一个估计，从任何生物体的总数量的生殖隔离与倒置隔离在自然种群。我们从751只疟疾媒介按蚊funestus沿着在喀麦隆1421公里的横断面，穿越萨凡纳，高原和热带雨林生态区的染色体。然后，我们开发了一系列的人口遗传模型，考虑到选择，迁移，和选择性交配，并拟合模型的数据使用的可能性。最佳拟合模型的结果表明，有很强的局部适应，与杂合子相比，纯合子的相对生存力范围从25%到130%。不同地区之间的生存能力有质的不同：在热带稀树草原上，反转是不显性的，而在高地上，它是显性的。这种倒位也与强烈的排斥性交配有关。在萨凡纳上，两种纯合子形式显示出92%的生殖隔离，这表明这一倒置可以产生物种形成所需的大部分遗传障碍。
Chromosome inversions have long been thought to be involved in speciation and local adaptation. We have little quantitative information, however, about the effects that inversion polymorphisms have on reproductive isolation and viability. Here we provide the first estimates from any organism for the total amount of reproductive isolation associated with an inversion segregating in natural populations. We sampled chromosomes from 751 mosquitoes of the malaria vector Anopheles funestus along a 1421 km transect in Cameroon that traverses savannah, highland, and rainforest ecological zones. We then developed a series of population genetic models that account for selection, migration, and assortative mating, and fit the models to the data using likelihood. Results from the best-fit models suggest there is strong local adaptation, with relative viabilities of homozygotes ranging from 25% to 130% compared to heterozygotes. Viabilities vary qualitatively between regions: the inversion is underdominant in the savannah, whereas in the highlands it is overdominant. The inversion is also implicated in strong assortative mating. In the savannah, the two homozygote forms show 92% reproductive isolation, suggesting that this one inversion can generate most of the genetic barriers needed for speciation.