Institut für Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum, Friedrich-Schiller-Universität, Erbertstr. 1, 07743, Jena, Germany.
Anim Genet. 2012 Oct;43(5):577-86. doi: 10.1111/j.1365-2052.2011.02300.x. Epub 2011 Dec 22.
As a result of strong artificial selection, the domesticated dog has arguably become one of the most morphologically diverse vertebrate species, which is mirrored in the classification of around 400 different breeds. To test the influence of breeding history on the genetic structure and variability of today's dog breeds, we investigated 12 dog breeds using a set of 19 microsatellite markers from a total of 597 individuals with about 50 individuals analysed per breed. High genetic diversity was noted over all breeds, with the ancient Asian breeds (Akita, Chow Chow, Shar Pei) exhibiting the highest variability, as was indicated chiefly by an extraordinarily high number of rare and private alleles. Using a Bayesian clustering method, we detected significant genetic stratification within the closely related Schnauzer breeds. The individuals of these three recently differentiated breeds (Miniature, Standard and Giant Schnauzer) could not be assigned to a single cluster each. This hidden genetic structure was probably caused by assortative mating owing to breeders' preferences regarding coat colour types and the underlying practice of breeding in separate lineages. Such processes of strong artificial disruptive selection for different morphological traits in isolated and relatively small lineages can result in the rapid creation of new dog types and potentially new breeds and represent a unique opportunity to study the evolution of genetic and morphological differences in recently diverged populations.
由于强烈的人工选择，家犬无疑成为了形态多样性最高的脊椎动物物种之一，这反映在大约 400 种不同品种的分类上。为了测试繁殖历史对当今犬种遗传结构和变异性的影响，我们使用一组来自 597 只个体的 19 个微卫星标记对 12 个犬种进行了研究，每个品种分析了大约 50 只个体。所有品种的遗传多样性都很高，古老的亚洲品种（秋田犬、松狮犬、沙皮犬）表现出最高的变异性，这主要表现为异常多的稀有和特有等位基因。使用贝叶斯聚类方法，我们在密切相关的雪纳瑞品种中检测到了显著的遗传分层。这三个最近分化的品种（迷你型、标准型和巨型雪纳瑞）的个体不能被分配到单个聚类中。这种隐藏的遗传结构可能是由于对毛色类型的选择性交配以及在不同血统中进行繁殖的做法造成的。这种对不同形态特征进行强烈人工破坏性选择的过程，在孤立的、相对较小的血统中，会导致新犬种的快速产生，并有潜力产生新的品种，这为研究遗传和形态差异在最近分化的群体中的进化提供了独特的机会。
