【摘要】 旨在利用721只固始鸡F2代鸡群，鉴定影响肌内脂肪沉积的候选基因G3BP1的SNPs位点，用于肉质性状的分子标记开发，并利用固始鸡肌内前脂肪细胞深入探究其功能。本研究首先鉴定了G3BP1基因上的SNPs位点，发现3个突变位点处于强连锁不平衡状态，尤其是13588667G>A位点的不同基因型与固始鸡F₂资源群的皮脂、皮脂率和肌内脂肪等肉质性状显著相关（P<0.05）。因此，G3BP1基因13588667G>A位点可以作为影响肌内脂肪沉积的一个重要的分子标记。此外，本研究利用qRT-PCR、CCK-8、流式细胞术、甘油三酯含量测定和油红O染色等方法，评价了G3BP1基因对固始鸡肌内前脂肪细胞增殖与分化的影响。结果表明，过表达G3BP1后，肌内前脂肪细胞中增殖标志基因CDK1、CCNB2、PCNA和CCND1表达水平均极显著上升（P<0.001）,并显著促进了细胞周期进程。过表达G3BP1后也显著促进了肌内前脂肪细胞分化标志基因LPL的表达（P<0.05）,极显著促进了CEBPA的表达（P<0.001）,肌内前脂肪细胞内脂滴生成和甘油三酯含量也极显著增加（P<0.01）。本研究明确了G3BP1在促进肌内前脂肪细胞增殖与脂肪细胞生成中的作用，并鉴定了影响肌内脂肪沉积的分子标记，为我国优质肉鸡培育提供重要的理论依据和应用价值。更多还原

【Abstract】 The study aimed to identify SNP sites of the candidate gene G3BP1 that influence intramuscular fat deposition using a population of 721 Gushi F2 chickens, to develop molecular markers for meat quality traits, and to further investigate its function using intramuscular preadipocytes from Gushi chickens. First, the study identified SNPs in G3BP1 gene and found 3 mutation sites in strong linkage disequilibrium, especially the different genotypes of the 13588667G>A site were significantly associated with the meat quality traits such as sebum, sebum rate and intramuscular fat in the F2 resource group of Gushi chicken(P<0.05). Therefore, the 13588667G>A site of the G3BP1 gene could be used as an important molecular marker affecting intramuscular fat deposition. Additionally, qRT-PCR, CCK-8, flow cytometry, triglyceride content determination and Oil Red O staining were used to evaluate the effect of G3BP1 gene on the proliferation and differentiation of intramuscular preadipocytes in Gushi chickens. The results showed that after overexpression of G3BP1, the expression levels of proliferation marker genes CDK1, CCNB2, PCNA and CCND1 in intramuscular preadipocytes were significantly increased(P<0.001), and the cell cycle process was significantly promoted. G3BP1 overexpression also significantly upregulated the expression of the differentiation marker gene LPL(P<0.05) and dramatically increased the expression of CEBPA(P<0.001), with a significant increase in lipid droplet formation and triglyceride content in intramuscular preadipocytes(P<0.01). This study clarifies the role of G3BP1 in promoting the proliferation and adipogenesis of intramuscular preadipocytes and identifies a molecular marker affecting intramuscular fat deposition, providing valuable theoretical and practical insights for breeding high-quality meat chickens in China.更多还原