【摘要】 肌肉生长抑制素(myostatin, MSTN)对骨骼肌生长起负调控作用；携有突变基因的动物均表现出优于普通动物的生长性能和产肉性能；而显著提高了产肉量是否会影响肉的品质，这是消费者普遍关心的问题。为此，本研究以MSTN基因编辑牛(Bos taurus)为材料，对其屠宰性状和肉用品质指标做了较为全面的分析。结果表明，MSTN编辑牛与对照牛的屠宰率分别为(60.83±4.68)%和(55.71±0.53)%，净肉率分别为(40.63±2.00)%和(37.62±0.79)%，均具有显著差异(P<0.05)。MSTN基因编辑牛的肉质，包括p H值、嫩度、系水力和营养物质等均与非双肌牛肉无统计学差异。应用RNA-seq和qPCR技术检测牛背最长肌肌肉组织基因的表达，MSTN基因突变影响了与脂肪沉积相关的基因，包括含脂联素、C1Q和胶原蛋白结构域(adiponectin, C1Q and collagen domain containing, ADIPOQ)、脂肪酸结合蛋白4 (fatty acid binding protein 4, FABP4)、脂肪酸合酶(fatty acid synthase, FASN)、脂蛋白脂肪酶(lipoprotein lipase, LPL)、过氧化物酶体增殖物激活受体γ (peroxisome proliferator-activated receptor γ, PPARγ)和硬脂酰辅酶A去饱和酶(stearoyl-CoA desaturase, SCD)的表达，降低了肌间脂肪含量，提高了瘦肉率。以上结果表明，MSTN基因的人工突变显著提高了鲁西黄牛的产肉性能，减少了肌内脂肪沉积，提高了瘦肉率，且牛肉的食用品质无显著变化。此研究为改良牛肉品质、培育高产肉牛新品种提供依据。更多还原

【Abstract】 Myostatin(MSTN) negatively regulates skeletal muscle growth, and the animals carrying the mutated gene all show better growth performance and meat production performance than the normal animals.Whether the significantly increased meat yield will affect the quality of meat is a general concern of consumers. In this study, the MSTN gene-edited cattle(Bos taurus) were used to examine the slaughter traits and meat quality indexes. The results showed that the slaughter rates of MSTN edited cattle and control cattle were(60.83±4.68)% and(55.71±0.53)%, and the net meat rates were(40.63±2.00)% and(37.62±0.79)%,respectively, with significant differences(P<0.05). The meat quality indexes such as pH value, tenderness,water power and nutrition of MSTN-edited cattle were all with no significant differences compared with the control cattle. Gene expressions of longissimus dorsi muscle detected by RNA-Seq and qPCR showed that MSTN mutation resulted in down-regulation of the genes associated with fat synthesis such as Adiponectin,C1Q and collagen domain containing(ADIPOQ), fatty acid binding protein 4(FABP4), fatty acid synthase(FASN), lipoprotein lipase(LPL), peroxisome proliferator-activated receptor γ(PPARγ), and stearoyl-CoA desaturase(SCD), decreased the intermuscular fat, and increased the lean meat production. In conclusion, the artificial mutation of MSTN gene can significantly improve the meat production performance of Luxi cattle,not change the meat quality, reduce intramuscular fat deposition, and improve the lean meat production.更多还原