北京鸭胸肌重选育的基因组微进化机制研究

畜禽育种的本质是人工选择压力下物种的微进化过程。虽然数量遗传学可以在一定程度上根据选择差和遗传力对遗传进展进行估计，但更精确的从基因组水平上解释选择进展的理论依旧缺乏，育种过程中的基因组变异规律和遗传优势效应累积方式亟待研究。家禽世代间隔短、繁殖力强、选择进展快，是研究育种机制的理想材料。本项目拟以胸肌重为目标性状、连续选育10个世代的北京鸭Z2系为研究对象，采用二代测序技术对10个世代的个体进行重测序，运用群体遗传学和统计遗传学方法，分别在宏观层面上分析群体遗传结构在世代间的变化规律；在微观层面上分析受选择基因在10个世代间基因频率和遗传效应的动态变化规律，从物种微进化角度揭示人工选择下基因组的响应模式，进而阐明胸肌选育过程中的多基因作用机制。本项目的实施将为理解畜禽数量性状在人工选择下的基因组微进化机制，揭开数量性状的“基因黑箱”，最终为畜禽重要经济性状分子育种提供新的参考和科学依据。

The essence of animal breeding is the microevolution process of species under artificial selection pressure. Although quantitative genetics approach could estimate the breeding progress to some extent based on selection differential and heritability, the theory for explaining genetic progress more accurately at the genomic level are still poorly understood. The pattern of genome variation and the accumulation mode of genetic dominance in breeding process were urgent to be studied. Poultry is an ideal material for breeding mechanism research, which has short generation interval, strong reproductive capacity, and fast selection progress. This project intends to take Pekin duck Z2 strain which was continuously selected on breast weight for 10 generations as the research object. We resequencing the individuals of 10 generations by applying the next generation sequencing (NGS) technology. Application the method of population genetics and statistical genetics approach, analysis the change law of population genetic structure between generations in the view of macroscopic, and analysis the law of dynamic variety of the selected gene frequency and genetics effect between 10 generations on a microscopic level. We will reveal the response of genome under artificial selection from the evolutionary perspective, then illustrate the polygene mechanism of breast weight in the breeding process. This study will elucidating the microevolution mechanism of quantitative trait in livestock under artificial selection, uncovering the ‘black box’ of quantitative traits, and ultimately provide the new reference and scientific basis for the molecular design breeding of economic important traits in farm animal.