影响鸡腹脂性状重要基因功能性SNP的鉴定和分析

Breeding broiler strains with low fat content is one of the world important goal for broiler breeders. Compared with the traditional selection methods, marker-assisted selection (MAS) for its unique advantages is widely expected to be used for low-fat broiler breeding. However, it is a premise for MAS that the important genes or molecular markers for growth and development of fatness tissue in broilers are screened and identified. Fifty one candidate genes have been screened by the combination of multiple different strategies, including physiological and biochemical pathways, gene expression profiling, protein expression profiling, QTL mapping, Genome-wide association study, and a total of 122 single nucleotide polymorphisms (SNPs) in above candidate genes detected during the past decade. In order to comprehensively evaluate the potentials of the application of these SNPs to MAS in breeding programme, assocations of these SNP markers with chicken abdominal fat traits will be conducted in multiple independent populations to further single out important SNP responsible for abdominal fat traits; Subsequently, the identification and analysis of the SNP functions will be carried out in an attemp to elucidate the molecular mechanism of action, which provide important references for the chicken and the other livestocks for molecular breeding.

选育专门化低脂肉鸡品系是世界范围内肉鸡育种重要的奋斗目标之一。与传统选种方法相比，分子标记辅助选择以其特有的优势有望广泛应用于低脂肉鸡的选育。实施标记辅助选择的前提是筛选和鉴定出影响肉鸡脂肪生长发育的重要基因或分子标记。十多年来，本课题组先后从不同的角度和层面（生理生化途径、基因表达谱、蛋白表达谱、QTL定位、全基因组关联分析）筛选出51个可能影响鸡腹脂性状形成的重要候选基因，检测到122个SNP位点。为了全面地梳理和评价这些基因的SNP位点能否在鸡育种中用于标记辅助选择，本项目拟对这些SNP标记在多个独立群体中开展与鸡腹脂性状的相关分析，筛选可能具有重要应用价值的遗传标记；在此基础上，进一步开展功能性SNP的鉴定和分析工作，努力阐明其作用的分子机理，从而为鸡乃至其它畜禽的分子育种提供重要参考。

选育专门化低脂肉鸡品系是世界范围内肉鸡育种重要的奋斗目标之一。鉴定分布于鸡DNA上不同区域的突变位点的功能性及调控机理是当前基因组学研究的热点，其研究成果不仅有助于阐明重要经济性状的遗传机理，而且有望将鉴定出的功能性标记应用于实际育种中对性状进行改良。.在本项目中，我们通过对20多个可能与鸡腹脂性状有关的候选基因48个多态位点在AA肉鸡随机群体、东北农业大学F2资源群体和腹脂双向选择品系多个群体中进行关联分析，鉴定和证实了许多显著影响鸡腹脂性状的突变位点；再此基础上，选择了ApoB、IGF1、OBR、UCP基因的4个SNP位点开展了功能性鉴定和机制分析，最终证实了ApoB g.-112A>G、IGF1 g.-119C>A、OBR g.7851G>A 、UCP g.1197A>C是功能性突变，并初步阐明了前三个突变影响鸡腹部脂肪沉积的分子机制。这些研究成果不但有助于揭示鸡腹脂性状的遗传基础，而且可以应用于培育低脂肉鸡标记辅助选择中，因此具有良好的应用前景。