Department of Animal Science, National Chung-Hsing University, Taichung, Taiwan.
Anim Genet. 2013 Aug;44(5):509-21. doi: 10.1111/age.12045. Epub 2013 May 28.
The aims of this study were to assess the genetic diversity of 17 populations of Vietnamese local chickens (VNN) and one Red Jungle Fowl population, together with six chicken populations of Chinese origin (CNO), and to provide priorities supporting the conservation of genetic resources using 20 microsatellites. Consequently, the VNN populations exhibited a higher diversity than did CNO populations in terms of number of alleles but showed a slightly lower observed heterozygosity. The VNN populations showed in total seven private alleles, whereas no CNO private alleles were found. The expected heterozygosity of 0.576 in the VNN populations was higher than the observed heterozygosity of 0.490, leading to heterozygote deficiency within populations. This issue could be partly explained by the Wahlund effect due to fragmentation of several populations between chicken flocks. Molecular analysis of variance showed that most of genetic variation was found within VNN populations. The Bayesian clustering analysis showed that VNN and CNO chickens were separated into two distinct groups with little evidence for gene flow between them. Among the 24 populations, 13 were successfully assigned to their own cluster, whereas the structuring was not clear for the remaining 11 chicken populations. The contributions of 24 populations to the total genetic diversity were mostly consistent across two approaches, taking into account the within- and between-populations genetic diversity and allelic richness. The black H'mong, Lien Minh, Luong Phuong and Red Jungle Fowl were ranked with the highest priorities for conservation according to Caballero and Toro's and Petit's approaches. In conclusion, a national strategy needs to be set up for Vietnamese chicken populations, with three main components: conservation of high-priority breeds, within-breed management with animal exchanges between flocks to avoid Wahlund effect and monitoring of inbreeding rate.
本研究旨在评估 17 个越南本地鸡（VNN）群体和一个红原鸡（RJF）群体的遗传多样性，以及 6 个中国起源的鸡群（CNO），并使用 20 个微卫星为遗传资源的保护提供优先事项。结果表明，就等位基因数而言，VNN 群体的遗传多样性高于 CNO 群体，但观察杂合度略低。VNN 群体共发现 7 个特有等位基因，而 CNO 群体则未发现特有等位基因。VNN 群体的期望杂合度为 0.576，高于观察杂合度 0.490，导致群体内杂合子缺失。这一问题可能部分可以用由于若干鸡群之间的种群碎片化导致的 Wahlund 效应来解释。分子方差分析表明，大部分遗传变异存在于 VNN 群体内。贝叶斯聚类分析表明，VNN 和 CNO 鸡分为两个不同的群体，它们之间几乎没有基因流的证据。在 24 个群体中，有 13 个被成功分配到自己的群体中，而其余 11 个鸡群的结构则不清楚。考虑到群体内和群体间的遗传多样性和等位基因丰富度，24 个群体对总遗传多样性的贡献在两种方法中大多是一致的。黑 H'mong、Lien Minh、Luong Phuong 和红原鸡根据 Caballero 和 Toro 以及 Petit 的方法被评为保护的最高优先级。综上所述，需要为越南鸡群制定国家战略，该战略有三个主要组成部分：保护高优先级品种、在品种内管理，通过群体间的动物交换来避免 Wahlund 效应，以及监测近交率。
