牛腰肌中μ-钙蛋白酶基因表达量 和蛋白活性与嫩度的关系

The relationship between μ-calpain gene expression and protein activity with tenderness in Longissimus Lumborum Muscle of Cattle

中文关键词: 关键词：牛肉  μ-钙蛋白酶  酪蛋白酶谱法  荧光定量PCR  嫩度

英文关键词: Keywords：beef  μ-calpain  casein zymography  fluorogenic quantitative PCR  tenderness

中文摘要:

      摘 要：牛肉嫩度是影响牛肉品质的重要因素，μ-钙蛋白酶是影响牛肉嫩度的关键酶。本研究的目的是探究夏南母牛，夏南公牛，西门塔尔公牛肉中μ-钙蛋白酶mRNA表达量和蛋白活性与嫩度的关系。本研究选取年龄为48月龄的夏南母牛三头，18月龄的夏南公牛三头，15月龄的西门塔尔公牛三头，以腰最长肌为研究对象。利用实时荧光定量PCR分析不同品种牛腰最长肌中μ-钙蛋白酶mRNA表达量；采用酪蛋白酶谱法分析成熟3天时不同样品μ-钙蛋白酶活性的差异；通过剪切力测定不同品种牛腰最长肌肉质嫩度的差异。结果发现：三个样品牛肉中μ-钙蛋白酶基因mRNA表达量差异不显著（P＞0.05）；夏南牛与西门塔尔牛肉中μ-钙蛋白酶活性差异极显著（P＜0.01）；夏南牛与西门塔尔牛剪切力差异极显著（P＜0.01）。结论：三个样品腰最长肌中μ-钙蛋白酶的mRNA表达量与牛肉嫩度无显著相关性，夏南母牛比夏南公牛嫩度好，夏南公牛比西门塔尔公牛嫩度好。

英文摘要:

      Abstract: Beef tenderness is an important factor of beef quality, and μ-calpain is the key enzyme which could affect the beef tenderness. The objective of this study was to investigate the relationship between μ-calpain mRNA expression and protein activity with tenderness in Xianan cattle and Simmental bull. The longissimus lumborum muscles were researched in this study and three Xianan cows aged 48 months, three Xianan bulls aged 18 months and three Simmental bulls aged 15 months were selected. Real-time fluorescence quantitative PCR was used to analyze the μ-calpain mRNA expression in longissimus lumborum muscles of different breeds. When aging time arrived 3d, the difference of μ-calpain activity in different samples was analyzed by casein zymography. The difference of tenderness among different breeds in longissimus lumborum muscles was measured by shear force. Results：These findings suggested that there was no significant difference in the mRNA expression of μ-calpain gene among the three cattle (P > 0.05). There was a significant difference in μ-calpain activity between Xianan cattle and Simmental cattle (P < 0.01).The difference of shear force between Xianan cattle and Simmental cattle was significant (P < 0.01). The conclusion was that there was no significant associated between the μ-calpain mRNA expression and beef tenderness in longissimus lumborum muscle of the different samples. The tenderness of Xianan cows was better than Xianan bulls, and the tenderness of Xianan bulls was better than Simmental bulls.