湖羊肌肉UCP3基因序列特征分析及其在肌肉中的表达

Characterization of UCP3 gene sequence and its expression in Hu lamb muscles

为了获得湖羊UCP3基因编码区全序列并分析其序列特征,同时研究其在湖羊不同部位肌肉中的表达变化,选取初生与1、2、3、4、5和6月龄湖羊公羔各5只,提取屠宰后背最长肌、腰大肌、前腿肱二头肌和后腿股二头肌RNA,用TA克隆技术获得湖羊UCP3基因编码区序列,用DNAMAN软件分析UCP3基因在哺乳动物间的保守性,同时基于UCP3蛋白质序列用MEGA5.1软件构建系统发育树,用Real-time PCR检测湖羊不同肌肉部位UCP3基因的表达水平并分析其在不同发育时期的变化。结果显示:湖羊UCP3基因编码区全长936 bp,编码311个氨基酸残基,在哺乳动物中相对保守。根据UCP3蛋白质氨基酸序列构建的系统发育树显示湖羊与牛的亲缘关系最近。Real-time PCR结果显示,初生至6月龄的湖羊不同部位肌肉UCP3基因的表达模式基本相似,即在出生时有较低的水平,然后上升,随着月龄的增加又下降,但UCP3基因在后腿股二头肌中的表达量整体偏低,在腰大肌中表达水平变化较大,3月龄的表达水平显著高于初生和5月龄。

This study aims to obtain the full coding region of UCP3 gene in Hu sheep, characterize its sequence and investigate the mRNA level in sheep muscles. Each five male Hu lamb at 0 to 6 months ages were chosen and slaughtered, and total RNA from longissimus muscles, psoas muscles and front and rear leg biceps femoris muscles were extracted. The coding region of UCP3 gene of Hu sheep was cloned using TA cloning technoloty, and its conservation among different mam-mals was analyzed using DNAMAN software. Its mRNA level of different muscles of Hu sheep was investigated using real time PCR. The results showed that the coding region of UCP3 gene in Hu sheep was 936 bp, encoding 311 amino acid residues, and was relatively conserved in mammals. Phylogenetic tree constructed based on protein sequence of UCP3 showed that the genetic relationship between Hu sheep and cattle was the closest. Real-time PCR results revealed that UCP3 in different parts of muscles of differently-aged Hu sheep shared similar mRNA expression patterns, which were low at birth, and went up slightly and down afterwards over age. The expression level of UCP3 gene was relatively low in the rear leg biceps femoris muscles, and fluctuated in psoas muscles. UCP3 gene showed higher levels in 3-mouth-old sheep than those in the newborns and 5-mouth-old sheep.