Abstract

The major histocompatibility complex (MHC) is surprisingly well associated with epidemiological and pathogenic environments, and the MHC-related microsatellite LEI0258 is a useful biomarker for indicating MHC haplotypes. In the present study, we conducted a comprehensive analysis of LEI0258 diversity in 492 Asian chickens and White Leghorns using multiple strategies to gain insight into the effectiveness of this adaptive locus for assessing the diversity and genetics of populations and the potential forces that affect MHC evolution. Comparisons between five Asian local breeds with wide geographic distributions and one commercial breed (White Leghorn chickens) revealed a total of 82 different alleles. The overall observed heterozygosity was 85.55% in Asian chickens and 30.98% in White Leghorn chickens, indicating higher LEI0258 diversity in Asian chickens than in the commercial breed. In addition, a population structure analysis of nine wild jungle fowl populations and several geographically varied Asian chicken populations revealed consistent clustering. Moreover, the results of AMOVA among jungle fowl populations suggested that most of the diversity was found among individuals within populations and within individuals. High levels of polymorphism and divergence were observed in the MHC region within and among populations, whereas limited polymorphisms and divergence were present among geographic groups. Hence, we concluded that the MHC in chickens has low intraspecific and interbreed variation and cannot be adapted as a tool to estimate diversity and migration based on drift and neutral events.

中文翻译：

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亚洲鸡群MHC-LEI0258基因座的遗传多样性格局

摘要

令人惊讶的是，主要的组织相容性复合体（MHC）与流行病学和致病性环境密切相关，并且MHC相关的微卫星LEI0258是指示MHC单倍型的有用生物标记。在本研究中，我们使用多种策略对492只亚洲鸡和白来亨鸡的LEI0258多样性进行了全面分析，以深入了解该适应性基因座的有效性，以评估种群的多样性和遗传学以及影响MHC进化的潜在力量。对五个地理分布广泛的亚洲本地品种与一个商业品种（白来亨鸡）进行比较，发现共有82个不同的等位基因。亚洲鸡总体观察到的杂合度为85.55％，白来亨鸡为30.98％，表明亚洲鸡的LEI0258多样性高于商业鸡。此外，对九个野生家禽种群和几个地理上不同的亚洲鸡种群的种群结构分析显示出一致的聚类。此外，在禽类种群中进行的AMOVA结果表明，大多数多样性是在种群内部和个体内部发现的。在人口内部和人群之间的MHC地区观察到高水平的多态性和差异，而在地理群体之间存在有限的多态性和差异。因此，我们得出的结论是，鸡体内的MHC具有较低的种内和杂种变异，因此不能作为基于漂移和中性事件来估计多样性和迁移的工具。对9个野生丛林家禽种群和几个地理上不同的亚洲鸡种群的种群结构分析显示出一致的聚类。而且，AMOVA在丛林禽类种群中的结果表明，大多数多样性是在种群内部和个体内部发现的。在人口内部和人群之间的MHC地区观察到高水平的多态性和差异，而在地理群体之间存在有限的多态性和差异。因此，我们得出的结论是，鸡体内的MHC具有较低的种内和杂种变异，因此不能作为基于漂移和中性事件来估计多样性和迁移的工具。对9个野生丛林家禽种群和几个地理上不同的亚洲鸡种群的种群结构分析显示出一致的聚类。而且，AMOVA在丛林禽类种群中的结果表明，大多数多样性是在种群内部和个体内部发现的。在人口内部和人群之间的MHC地区观察到高水平的多态性和差异，而在地理群体之间存在有限的多态性和差异。因此，我们得出的结论是，鸡体内的MHC具有较低的种内和杂种变异，因此不能作为基于漂移和中性事件来估计多样性和迁移的工具。