C4BPA基因介导的牛乳脂代谢和免疫性状协同调控机制研究

乳脂性状是影响乳品质的主要因素，也是奶牛育种工作的目标性状。乳脂代谢功能基因筛选一直是奶牛分子育种的研究热点。课题组在高脂和低脂牛乳腺上皮细胞系转录组分析时发现，在无免疫细胞干扰情况下，部分免疫相关基因在乳腺上皮细胞中差异表达，暗示这些免疫相关基因可能对乳脂和免疫性状均具调控作用。这些基因是否在调控奶牛乳脂代谢同时，影响免疫性状并调控疾病发生易感性尚待进一步研究。本项目以C4BPA为候选基因，采用过表达和干扰初步分析对乳脂和免疫性状的调控作用；采用CRISPR/Cas9技术，构建敲除和过表达乳腺上皮细胞系及小鼠模型，探讨该基因对乳脂和免疫性状的协同调控通路；采用免疫荧光技术，了解该基因对乳脂和免疫性状协同调控细胞学基础；构建炎性诱导细胞和动物模型，解析该基因对乳脂和免疫性状的调控网络，揭示该基因对乳脂与免疫性状协同作用分子机制，为C4BPA基因在乳品质和抗病协同育种中的应用奠定理论基础。

Milk fat trait is the main factor affecting milk quality, and it is also the target traits of dairy cattle breeding. The screening of functional genes for milk fat metabolism has always been a research hotspot in dairy cattle molecular breeding. In our previous study, the transcriptome analysis of high-fat and low-fat bovine mammary epithelial cell lines revealed that some immune-related genes were differentially expressed without immune cell interference, suggesting that these immune-related genes may have regulatory effects on both milk fat and immune traits. Whether these genes regulate the milk fat metabolism of cows, but also affect the immune traits and the susceptibility of disease occurrence needs further study. In this study C4BPA is selected as the candidate gene, based on the preliminary analysis of the synergistic regulation of C4BPA on milk fat and immune traits by overexpression and RNA interference, CRISPR/cas9 is used to construct knockout and overexpression mammary epithelial cell lines and mouse models, and immunofluorescence is used to understand the cytological basis of the synergistic regulation of milk fat and immune traits; On the basis of inflammatory induced cells and animal models, the synergistic regulatory pathways and regulatory networks are analyzed, and the molecular mechanism of the C4BPA for milk fat and immune traits is clarified. This study lays a theoretical foundation for the application of the C4BPA gene in cooperative breeding of milk quality and disease resistance.