代谢参与调控不同品种猪肌肉发育差异的研究

提高地方猪瘦肉产量是国家现代种业发展的重大现实需求。在前期研究中，申请人提出并证实了地方猪产肉量少，是因为其成肌细胞增殖能力强，率先达到彼此接触状态，促进细胞早分化，最终用于形成肌纤维的成肌细胞数减少，所以产肉量少。为什么产肉量少的猪成肌细胞增殖能力更强呢？以往研究主要集中于基因表达调控，但这并不能从根本上解决问题。我们新近观察到，产肉量不同猪种代谢组存在显著差异，且已证实胚胎35天时蓝塘猪的三羧酸循环和核酸代谢更强，有利于细胞的分裂增殖，这与预期完全相符。为此本课题拟增加胚胎21天、28天肉样组织筛选并通过肌肉特异性敲除靶基因证实影响成肌细胞增殖乃至骨骼肌发育的代谢通路和代谢酶基因，并从转录调控层面探究关键代谢物在地方猪胚胎中具有高丰度的原因，同时探讨不同品种猪代谢物差异是否存在时空特异性，为确立将代谢物差异及其遗传调控作为提高生猪产肉量新靶标提供科学理论依据。

Improving the lean meat production of indigenous pigs is an important practical demand for the development of modern seed industry. In the previous studies, the applicant proposed and confirmed that the indigenous pigs produced less meat because of their robust myoblasts proliferation capacity, which converged earlier, and then promoted MyoD and other myogenic genes expression earlier, leading to early differentiation of myoblasts, so there was no more time to proliferate, and the number of myoblasts used to form muscle fibers was less, as a result, the meat production was less. Why is the proliferation capacity of myoblasts in pigs with less muscle robust? Previous studies mainly focused on gene expression regulation, but this can not fundamentally solve the problem. We have recently found that there are significant differences in metaboliome among pigs differing in muscle mass, and it has been confirmed that the TCA cycle and nucleic acid metabolism of Lantang pig is higher abundance at E35, which contributes to cell division and proliferation. This is completely consistent with the expectation. Therefore, this project plans to increase the screening of E21 and E28 embryonic tissues and confirm the metabolic pathway and metabolic enzyme genes that affect myoblast proliferation and skeletal muscle development through muscle specific knockout target genes, and to find out the reason of high abundance for the key metabolites in indigenous pig embryos from the transcriptional regulation level, and to explore whether there is spatiotemporal specificity in metabolites difference between pig breeds. It provides a scientific theoretical basis for the establishment of metabolite difference and its genetic regulation as a new target to improve the meat production of pigs.