Fine-scale genetic structure in a free-living ungulate population
Fine-scale genetic structure in a free-living ungulate population
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DOI：
10.1046/j.1365-294x.2003.01762.x
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发表时间：
2003-03-01
影响因子：
4.9
通讯作者：
Pemberton, JM
中科院分区：
文献类型：
--
作者：
Coltman, DW;Pilkington, JG;Pemberton, JM
野生动物种群的精细遗传结构很少被分析，但在数量遗传和等位基因关联研究中可能是一个重要的混杂因素，并对种群动态、近亲繁殖和亲缘选择有影响。在这项研究中，我们利用来自20个微卫星和蛋白质座位的数据，研究了苏格兰圣基尔达Soay绵羊(Ovis Aries)村湾种群的三个空间亚基或重量的遗传结构程度。在我们考虑的所有研究年份(1987-2000年包括在内)，等位基因频率在三个体重之间存在显著差异。在大多数年份观察到小但显著正的F(ST)和负的F(IS)值，这表明重量是遗传分化的，并且每个重量内观察到的杂合度比如果每个重量是一个孤立的繁殖群体所期望的要多。男性对出生体重的忠诚度较低，因此女性体重内的关联程度高于男性。在涉及女性的配对比较中，地理接近与亲缘关系存在显著的负相关，平均而言，相距50米以内的一对女性在同等水平上属于第二近亲。因此，结构在很大程度上是由雌性在出生后不完全的扩散所驱动的。就重量的空间遗传亚结构而言，交配似乎是随机的，因此遗传结构对种群的总体近亲交配率没有贡献。然而，遗传亚结构可能导致等位基因关联，并在谱系内产生环境效应，这可能会混淆遗传力分析和等位基因关联研究。
The fine-scale genetic structure of wild animal populations has rarely been analysed, yet is potentially important as a confounding factor in quantitative genetic and allelic association studies, as well as having implications for population dynamics, inbreeding and kin selection. In this study, we examined the extent to which the three spatial subunits, or hefts, of the Village Bay population of Soay sheep (Ovis aries ) on St Kilda, Scotland, are genetically structured using data from 20 microsatellite and protein loci. Allele frequencies differed significantly among three hefts in all the study years we considered (1987-2000 inclusive). Small but significantly positive F (ST) and negative F (IS) values were observed in most years, indicating that the hefts are genetically differentiated, and that within each heft there is more observed heterozygosity than would be expected if each were an isolated breeding population. Males showed less fidelity to their natal heft, and as a consequence higher levels of relatedness within hefts were observed among females than among males. There was a significant negative relationship between geographical proximity and relatedness in pairwise comparisons involving females, and on average pairs of females located within 50 m of each other were related at the equivalent level of second cousins. Structure is therefore largely driven by incomplete postnatal dispersal by females. Mating appears to be random with respect to the spatial-genetic substructure of the hefts, and therefore genetic structure does not contribute to the overall rate of inbreeding in the population. However, genetic substructure can lead to allelic associations and generate environmental effects within lineages that have the potential to confound heritability analyses and allelic association studies.