Department of Animal Science, University of Padova, Viale dell'Università, Legnaro (PD), Italy.
Poult Sci. 2010 Mar;89(3):420-7. doi: 10.3382/ps.2009-00324.
The objectives of this study were to determine genetic variation and to analyze population structure of 6 Italian local chicken breeds involved in a conservation program. Twenty microsatellite markers were investigated in 337 birds belonging to 6 breeds: Ermellinata di Rovigo, Robusta Maculata, Robusta Lionata, Pépoi, Padovana, and Polverara; a commercial layer cross was used as reference. One hundred twelve alleles were detected in the overall population, with a mean number of 5.6 +/- 2.1 alleles per locus. For the local breeds, the observed and expected heterozygosity ranged from a minimum of 0.240 to a maximum of 0.413 and from 0.243 to 0.463 for the Pépoi and Polverara breeds, respectively. Deviation from Hardy-Weinberg equilibrium was observed in 5 breeds and in the commercial cross. The overall population heterozygote deficiency was 0.427, the average inbreeding coefficient was 0.097, and the heterozygote deficiency due to breed subdivisions was 0.437. Reynolds' distances were used to draw an unrooted neighbor-joining tree, which topology gave information on the genetic origin of these breeds and confirmed their known history. The estimated molecular kinship within a breed ranged from 0.559 to 0.769, evidencing high coancestry. Structure analysis was performed to detect the presence of population substructures. Inferred clusters corresponded to the different breeds, without presence of admixture. The exception was the Polverara breed, for which a more complex genetic structure was found. The results supported the decision of safeguarding these breeds as an important reservoir of genetic diversity and confirmed the usefulness of microsatellite markers to characterize and to monitor genetic variability in local chicken breeds.
本研究旨在确定 6 个参与保护计划的意大利本地鸡品种的遗传变异和分析其群体结构。在 337 只属于 6 个品种的鸟类（Ermellinata di Rovigo、Robusta Maculata、Robusta Lionata、Pépoi、Padovana 和 Polverara）和一个商业层鸡杂交种中研究了 20 个微卫星标记。在整个群体中检测到 112 个等位基因，每个位点的平均等位基因数为 5.6 +/- 2.1。对于本地品种，观察到和预期的杂合度范围从最低的 0.240 到最高的 0.413，Pépoi 和 Polverara 品种分别为 0.243 和 0.463。5 个品种和商业杂交种偏离 Hardy-Weinberg 平衡。总体群体杂合子不足为 0.427，平均近交系数为 0.097，由于品种细分导致的杂合子不足为 0.437。使用 Reynolds 距离绘制无根邻接树，拓扑结构提供了这些品种遗传起源的信息，并证实了它们已知的历史。品种内估计的分子亲缘关系范围为 0.559 至 0.769，表明高度同源。结构分析用于检测群体亚结构的存在。推断的聚类与不同的品种相对应，没有混杂。Polverara 品种是个例外，发现其遗传结构更为复杂。结果支持保护这些品种作为遗传多样性的重要储备的决定，并证实了微卫星标记用于表征和监测本地鸡品种遗传变异性的有用性。
