草鱼PGC-1β基因克隆及高糖高脂饲料对其表达的影响

Molecular cloning of PGC-1β gene and effects of high carbohydrate and high fat feed on its expression in liver of grass carp Ctenopharyngodon idella

为探讨过氧化物酶体增殖物激活受体γ辅激活因子-1β基因在草鱼能量代谢中的作用,本研究克隆了草鱼PGC-1β基因的核心序列,并对其进行了生物信息学分析;利用Real-time PCR技术检测了PG C-1β在不同组织中的表达状况;同时研究了饥饿、饥饿再投喂及高糖(糖含量45%)高脂(脂含量8%)饲料对草鱼肝脏PGC-1β表达的影响。结果显示,所获得的草鱼PGC-1β基因部分c DNA片段长为885 bp(Gen Bank登录号:KM580493.1),共编码293个氨基酸,与斑马鱼的同源性为81%;该基因在脑中的表达量最高,肠和肝脏次之;与正常投喂组相比,饥饿(7 d)导致PGC-1β在肝脏中的mRNA水平显著升高,饥饿再投喂后几乎恢复到对照组的表达水平。饲喂高脂以及高糖高脂饲料(65 d)后,与对照组相比,草鱼肝脏中PGC-1β的mRNA水平显著升高。研究结果表明,PG C-1β基因在草鱼能量代谢旺盛的组织中高表达,同时饥饿处理、饲料糖和脂肪水平等营养状况显著影响PGC-1βmRNA的表达。以上提示,PGC-1β在草鱼能量代谢过程中可能起到重要作用。

To investigate the mechanism of peroxisome proliferator-activated receptor-γ coactivator-1 beta（ PGC-1β） in the energy metabolism of grass carp Ctenopharyngodon idella,the partial c DNA of PGC-1βwas cloned,and tissue expression and nutritional regulation were investigated. The partial c DNA was 885 bp（ Gen Bank number： KM580493. 1）,encoding a polypeptide of 293 amino acids,compared to zebra fish,it showed 81% homology. Quantitative real-time PCR showed that highest PG C-1β mRNA expression was detected in brain,followed by intestine and liver. PG C-1β gene expression levels in liver were significantly increased during 7 days of fasting and decreased to normal level after refeeding. The expression of PG C-1βwas significantly affected by dietary lipid and carbohydrate,significantly higher in liver of fish fed the diet with high carbohydrate and high lipid. The results indicate that PG C-1β is regulated by the energy expenditure status,which implies it plays an important role in energy metabolism in grass carp.