CIRAD, UPR AGIRS, Campus International de Baillarguet, F-34398 Montpellier, France.
BMC Genet. 2010 Jun 18;11:53. doi: 10.1186/1471-2156-11-53.
Chickens represent an important animal genetic resource and the conservation of local breeds is an issue for the preservation of this resource. The genetic diversity of a breed is mainly evaluated through its nuclear diversity. However, nuclear genetic diversity does not provide the same information as mitochondrial genetic diversity. For the species Gallus gallus, at least 8 maternal lineages have been identified. While breeds distributed westward from the Indian subcontinent usually share haplotypes from 1 to 2 haplogroups, Southeast Asian breeds exhibit all the haplogroups. The Vietnamese Ha Giang (HG) chicken has been shown to exhibit a very high nuclear diversity but also important rates of admixture with wild relatives. Its geographical position, within one of the chicken domestication centres ranging from Thailand to the Chinese Yunnan province, increases the probability of observing a very high genetic diversity for maternal lineages, and in a way, improving our understanding of the chicken domestication process.
A total of 106 sequences from Vietnamese HG chickens were first compared to the sequences of published Chinese breeds. The 25 haplotypes observed in the Vietnamese HG population belonged to six previously published haplogroups which are: A, B, C, D, F and G. On average, breeds from the Chinese Yunnan province carried haplotypes from 4.3 haplogroups. For the HG population, haplogroup diversity is found at both the province and the village level (0.69).The AMOVA results show that genetic diversity occurred within the breeds rather than between breeds or provinces. Regarding the global structure of the mtDNA diversity per population, a characteristic of the HG population was the occurrence of similar pattern distribution as compared to G. gallus spadiceus. However, there was no geographical evidence of gene flow between wild and domestic populations as observed when microsatellites were used.
In contrast to other chicken populations, the HG chicken population showed very high genetic diversity at both the nuclear and mitochondrial levels. Due to its past and recent history, this population accumulates a specific and rich gene pool highlighting its interest and the need for conservation.
鸡是一种重要的动物遗传资源，保护地方品种是保护这一资源的关键。一个品种的遗传多样性主要通过其核多样性来评估。然而，核遗传多样性并不能提供与线粒体遗传多样性相同的信息。对于鸡这个物种，已经确定了至少 8 条母系。虽然分布在印度次大陆以西的品种通常共享来自 1 到 2 个单倍群的单倍型，但东南亚的品种则表现出所有的单倍群。越南的哈冈（HG）鸡已被证明具有非常高的核多样性，但也与野生亲缘种存在重要的杂交率。其地理位置位于泰国到中国云南省的一个鸡驯化中心范围内，增加了观察母系遗传多样性的可能性，在某种程度上，也提高了我们对鸡驯化过程的理解。
首先将 106 个来自越南 HG 鸡的序列与已发表的中国品种的序列进行比较。在越南 HG 种群中观察到的 25 个单倍型属于之前发表的 6 个单倍群，即 A、B、C、D、F 和 G。平均而言，来自中国云南省的品种携带来自 4.3 个单倍群的单倍型。对于 HG 种群，无论是在省还是村庄一级，都发现了单倍群多样性（0.69）。AMOVA 结果表明，遗传多样性发生在品种内部，而不是品种之间或省份之间。关于每个种群的 mtDNA 多样性的全球结构，HG 种群的一个特征是与 G. gallus spadiceus 相比，其模式分布相似。然而，与微卫星观察到的情况一样，没有发现野生和家养群体之间存在基因流动的地理证据。
与其他鸡群相比，HG 鸡群在核和线粒体水平上都表现出非常高的遗传多样性。由于其过去和现在的历史，该种群积累了一个独特而丰富的基因库，突出了其保护的重要性和必要性。
