虹鳟PPARα基因克隆、序列分析及其组织表达分布

Cloning,sequence analysis,and expression distribution of PPARα from rainbow trout

克隆了虹鳟（Oncorhynchus mykiss）过氧化物酶体增殖物激活受体（peroxisome proliferator activated receptor,PPAR）αmRNA全序列。对其序列分析发现,虹鳟PPARα与其他脊椎动物PPARα有较高的同源性,其中mRNA序列有66.4%~97.5%相同,氨基酸序列有69.2%~98.9%相同。DNA结合结构域和配体结合结构域从鱼类到人类高度保守,其中DNA结合结构域有88.0%~98.8%的氨基酸序列相同;配体结合结构域有74.6%~99.6%的氨基酸序列相同。系统发生树分析表明,虹鳟的PPARα基因与同属鲑科鱼类的大西洋鲑（Salmo salar）属于同一分支。实时定量RT-PCR方法分析虹鳟不同组织中的表达发现,PPARα基因在脂肪、肌肉、卵巢、肾脏和肠中表达量较高。

Peroxisome proliferator-activated receptors （PPARs） belong to the nuclear receptor superfamily, which regulates the biosynthesis and metabolism of lipids, and the differentiation and formation of lipocytes. PPARa mRNA from the rainbow trout （Oncorhynehus mykiss） was cloned by RT-PCR. Sequence homology analysis showed that rainbow trout PPARa gene was similar to those reported in other vertebrate species. The mRNA se- quence and the deduced amino acid sequence of rainbow trout PPARa showed identities of 66.4%-97.5% and 72.5%-93.8%, respectively, with those of other vertebrates. The DNA-binding domain and the ligand-binding domain of PPAR~ have been highly conserved in the evolution from fish to humans, which show 88.0%-98.8% and 74.6%-99.6% amino acid sequence identities, respectively, with those of other vertebrates. Phylogenetic analysis indicated that PPARa of rainbow trout and Atlantic salmon （Salmo salar） belong to the same branch of the phylogenetie tree. Using quantitative real-time RT-PCR, we observed that rainbow trout mRNA was expressed predominantly in lipid, muscle, ovarian, renal, and intestinal tissues.