【作者】 曲鲁江； 李显耀； 徐桂芳； 陈宽维； 杨红杰； 张龙超； 吴桂琴； 侯卓成； 徐桂云； 杨宁；

【Author】 Lujiang Qu Xianyao Li Guifang Xu Kuanwei ChenHongjie Yang Longchao Zhang Guiqin Wu Zhuocheng HouGuiyun Xu Ning Yang( College of Animal Science and Technology, China AgriculturalUniversity, Beijing 100094, China) ( National Service for Animal Husbandry and Veterinarian,Beijing 100026, China)( Institute of Poultry Science, Chinese Academy of Agricultural Science, Yangzhou, Jiangsu 200331, China)

【机构】 中国农业大学动物科技学院； 全国畜牧兽医总站； 中国农业科学院家禽研究所；

【摘要】 中国地大物博、幅员辽阔,拥有丰富的鸡种遗传资源。由于中国地方鸡种生产性能相对较低,很难与国内外家禽公司育成的商业品种竞争,现存数目较少,有些已经濒临灭绝。为了进一步了解中国地方鸡品种的遗传多样性状况,本研究采集来分布于中国各地的78个地方鸡品种的血样,并利用分布于13条染色体上27个微卫星标记进行了分析。通过对总共2740个个体的检测分析,在所有27个微卫星座位中,等位基因数从6到51个不等,平均值为18.74。所检测的78个品种的杂合度(H)均在0.5以上,所有品种的平均杂合度值为0.622,多态信息含量(PIC)平均值为0.573。这一结果表明,与国外的同类研究相比,中国的地方鸡品种具有更加广泛的遗传多样性。在27个微卫星座位中,总群内亚群的固定系数(FST)从0.065(LEI0166)到0.209(MCW0078)不等,平均值为0.106。在检测的位点中,只有LEI0194位点在所有的群体中均偏离了Hardy-Weinberg平衡(HWE),而其它位点基本上都处于Hardy-Wein-berg平衡状态。由于小群体中的基因漂移及非随机交配,一些在保种场保存的地方品种(如狼山鸡等)的杂合度相对较低,而在保种区的品种由于保种群群体较大,杂合度也就相对较高。中国地方鸡品种的高杂合度与其表型多样性是一致的。通过Nei氏遗传距离和邻接法将中国地方鸡种进行聚类,结果表明,中国地方鸡品种可以分为六大类,分类结果与品种的地理分布基本一致。本实验通过分子生物学手段分析了中国地方鸡品种的遗传多样性,这将对中国地方鸡品种的利用和保护提供重要的理论依据。更多还原

【Abstract】 China is rich in chicken genetic resources, and many indigenous breeds can be found throughout the country. Due to poor productive ability, some of them are threatened by the commercial varieties from domestic and foreign breeding companies. In a large - scale investigation into the current status of Chinese poultry genetic resources, 78 indigenous chicken breeds were surveyed and their blood samples collected. The genomes of these chickens were screened using microsatellite analysis. A total of 2, 740 individuals were genotyped for 27 microsatellite markers on 13 chromosomes. The number of alleles of the 27 markers ranged from 6 to 51 per locus with a mean of 18. 74. Heterozygosity (H) values of the 78 chicken breeds were all more than 0. 5. The average H value (0. 622) and polymorphism information content (PIC, 0. 573) of these breeds suggested that the Chinese indigenous chickens possessed more genetic diversity than that reported in many other countries. The fixation coefficients of subpopulations within the total population (Fsr) for the 27 loci varied from 0. 065 (LEI0166) to 0. 209 (MCW0078), with a mean of 0.106. For all detected microsatellite loci, only one (LEI0194) deviated from Hardy-Weinberg equilibrium (HWE) across all the populations. As genetic drift or non - random mating can occur in small populations, breeds kept on conservation farms such as Langshan chicken generally had lower H values, while those kept on large populations within conservation regions possessed higher polymorphisms. The high genetic diversity in Chinese indigenous breeds is in a-greement with great phenotypic variation of these breeds. Using Nei’s genetic distance and the NeighboR - Joining method, the indigenous Chinese chickens were classified into six categories that were generally consistent with their geographic distributions. The molecular information of genetic diversity will play an important role in conservation, supervision, and utilization of the chicken resources.更多还原