Bayesian analyses of admixture in wild and domestic cats (Felis silvestris) using linked microsatellite loci
Bayesian analyses of admixture in wild and domestic cats (Felis silvestris) using linked microsatellite loci
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DOI：
10.1111/j.1365-294x.2005.02812.x
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发表时间：
2006-01-01
影响因子：
4.9
通讯作者：
Randi, E
中科院分区：
文献类型：
--
作者：
Lecis, R;Pierpaoli, M;Randi, E
近年来发展起来的推断群体结构和混合物的方法大多使用非连锁中性标记描述的个体基因型。然而，独立标记间的Hardy-Weinberg不平衡和连锁不平衡随着混合时间的延长而迅速下降，混合信号可能在几代内丢失。在这项研究中，我们的目的是描述182个欧洲野生猫和家猫（Felis silvestris），偶尔在意大利和匈牙利广泛杂交的遗传混合物。猫的基因分型在27个微卫星，包括21个连锁位点映射在5个不同的猫连锁群。基因型进行了分析与结构2.1，贝叶斯程序设计的混合物连锁不平衡模型，这有望有效地评估使用紧密连锁的标记物的旧的混合事件。结果表明，在意大利采样的家猫和野猫被分成两个不同的聚类，平均隶属比例Q > 0.90，与先前的形态鉴定一致。相比之下，在匈牙利采样的自由生活的猫被部分分配到家猫和野猫集群，Q < 0.50。混合物分析的个别基因型确定，分别为5/61（8%），和16-20/65（25-31%）之间的意大利野猫和匈牙利自由生活的猫杂交。过去使用非连锁基因座也获得了类似的结果，尽管新的连锁标记在意大利鉴定出了额外的混合野猫。连锁分析证实，杂交是有限的，在意大利，但广泛分布在匈牙利野猫，一个人口的威胁与自由放养的家猫杂交繁殖。总面板的27个位点的表现优于单独的连锁位点在国内和已知的杂交猫的识别，这表明，大量的连锁加非连锁标记可以提高混合物分析的结果。推断的重组事件导致确定染色体片段的起源群体，这表明混合作图实验也可以在野生群体中设计。
Methods recently developed to infer population structure and admixture mostly use individual genotypes described by unlinked neutral markers. However, Hardy-Weinberg and linkage disequilibria among independent markers decline rapidly with admixture time, and the admixture signals could be lost in a few generations. In this study, we aimed to describe genetic admixture in 182 European wild and domestic cats (Felis silvestris), which hybridize sporadically in Italy and extensively in Hungary. Cats were genotyped at 27 microsatellites, including 21 linked loci mapping on five distinct feline linkage groups. Genotypes were analysed with structure 2.1, a Bayesian procedure designed to model admixture linkage disequilibrium, which promises to assess efficiently older admixture events using tightly linked markers. Results showed that domestic and wild cats sampled in Italy were split into two distinct clusters with average proportions of membership Q > 0.90, congruent with prior morphological identifications. In contrast, free-living cats sampled in Hungary were assigned partly to the domestic and the wild cat clusters, with Q < 0.50. Admixture analyses of individual genotypes identified, respectively, 5/61 (8%), and 16-20/65 (25-31%) hybrids among the Italian wildcats and Hungarian free-living cats. Similar results were obtained in the past using unlinked loci, although the new linked markers identified additional admixed wildcats in Italy. Linkage analyses confirm that hybridization is limited in Italian, but widespread in Hungarian wildcats, a population that is threatened by cross-breeding with free-ranging domestic cats. The total panel of 27 loci performed better than the linked loci alone in the identification of domestic and known hybrid cats, suggesting that a large number of linked plus unlinked markers can improve the results of admixture analyses. Inferred recombination events led to identify the population of origin of chromosomal segments, suggesting that admixture mapping experiments can be designed also in wild populations.