Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.
Mol Ecol. 2010 Dec;19(23):5172-85. doi: 10.1111/j.1365-294X.2010.04867.x. Epub 2010 Nov 2.
Heterozygosity-fitness correlations (HFCs) are frequently used to examine the relationship between genetic diversity and fitness. Most studies have reported positive HFCs, although there is a strong bias towards investigating HFCs in genetically impoverished populations. We investigated HFCs in a large genetically diverse breeding population of Kentish plovers Charadrius alexandrinus in southern Turkey. This small shorebird exhibits highly variable mating and care systems, and it is becoming an ecological model species to understand breeding system evolution. Using 11 conserved and six anonymous microsatellite markers, we tested whether and how heterozygosity was associated with chick survival, tarsus and body mass growth controlling for nongenetic effects (chick sex, hatching date, length of biparental care and site quality) that influence survival and growth. There was no genome-wide effect of heterozygosity on fitness, and we did not find any significant effects of heterozygosity on growth rates. However, two of the 11 conserved markers displayed an association with offspring survival: one marker showed a positive HFC, whereas the other marker showed a negative HFC. Heterozygosity at three further conserved loci showed significant interaction with nongenetic variables. In contrast, heterozygosity based on anonymous microsatellite loci was not associated with fitness or growth. Markers that were correlated with chick survival were not more likely to be located in exons or introns than other markers that lacked this association.
杂合度-适合度相关（HFCs）常用于研究遗传多样性与适合度之间的关系。尽管大多数研究都报告了正的 HFCs，但实际上存在着强烈的偏向性，即偏向于研究遗传贫瘠种群中的 HFCs。我们在土耳其南部一个具有丰富遗传多样性的繁殖种群中调查了肯特郡滨鸟（Charadrius alexandrinus）的 HFCs。这种小型滨鸟表现出高度可变的交配和育雏系统，它正在成为一种生态模式物种，用于理解繁殖系统的进化。我们使用 11 个保守和 6 个匿名微卫星标记，测试了杂合度是否以及如何与雏鸟的存活率、跗跖和体重生长相关，同时控制了影响存活率和生长的非遗传效应（雏鸟性别、孵化日期、双亲育雏时间和地点质量）。杂合度对适合度没有全基因组影响，我们也没有发现杂合度对生长率有任何显著影响。然而，11 个保守标记中的两个与后代存活率有关：一个标记显示出正的 HFC，而另一个标记显示出负的 HFC。三个进一步的保守位点的杂合度与非遗传变量之间存在显著的相互作用。相比之下，基于匿名微卫星位点的杂合度与适合度或生长无关。与雏鸟存活率相关的标记与其他没有这种关联的标记相比，位于外显子或内含子中的可能性并不更高。
