影响鸡体重性状重要基因的致因突变分离及功能验证

As one of the most popular livestock, chicken has provided plenty of eggs and meat for human daily life. Body weight is one of the most important economic characters for commercial broilers. Deciphering the genetic mechanisms and the molecular processes that regulating body weight is of great importance on breed-improvement for domestic chickens. Here, we are to utilize a F9 resource population which we designed before using the Huiyang Bearded chicken and the High Quality of Lingnan yellow-feathered broilers to fine-mapping the intervals of QTLs that contributing to body weight on GGA1. Combined analyses will be conducted on the sequence and candidate genes in the minimum QTL interval to figure out causal mutations and functional genes regulating the growth characteristics. Gene expression, immunohistochemistry and in situ hybridization will be used to validate the mapping result and dissect the molecular mechanism for both genomic variants and genes leading to the change in body weight . The ultimate goal for this study is to provide a basis for chicken breed-improvement.

鸡是重要的农业动物，为人类日常生活提供蛋类和肉类食品。生长性状是商业肉鸡最重要的经济性状,揭示影响鸡生长的遗传学与分子生物学机制对鸡的遗传育种改良具有重要意义。本项目利用前期建立的惠阳胡须鸡和岭南黄鸡快长型父系商业肉鸡为亲本的F9代深度杂交系群体，对1号染色体影响体重性状的QTL进行精细定位。结合QTL区间候选基因的基因表达模式分析与候选区间DNA序列变异分析对控制体重性状的功能基因以及致因突变进行定位。利用分子生物学实验对定位结果进行验证，并探索功能基因与致因突变影响体重性状的分子机理，为鸡的遗传育种改良提供依据。

生长性状是商业肉鸡最重要的经济性状，揭示影响鸡生长的遗传学与分子生物学机制对鸡的遗传育种改良具有重要意义。本项目利用前期建立的惠阳胡须鸡和岭南黄鸡快长型父系商业肉鸡为亲本的F9代深度杂交系群体，对1号染色体和27号染色体影响体重等生长性状的QTL进行精细定位。多种关联分析的结果鉴定该区域存在紧密连锁的多个功能位点，均对鸡的体重等生长表型存在显著影响。多群体分析共鉴定到1号染色体末端9个Kb级别的候选区段并从中选择性地证明了其中一个区段的关键调控突变在十二指肠发育中发挥的关键作用。该研究是精细拆分复杂数量性状QTL的首次尝试，为后续各类数量性状精细定位提供了示范。为了从个体水平研究候选基因/突变的功能，本研究还利用SSEA4抗体介导的M168假型化慢病毒实现了靶向PGCs的特异感染，结合显微注射法成功制备了生殖不育工具鸡，有效提高了筛选G1代转基因鸡的效率。综上，本研究为鸡的育种改良提供了分子遗传学的理论基础和基因编辑的技术指导。