黄河裸裂尻鱼肥胖基因克隆及其对青藏高原季节性冷环境的适应性表达

目的克隆黄河裸裂尻鱼肥胖基因(obese gene,ob),分析编码蛋白leptin的序列特征,检测ob mR-NA的组织特异性表达和不同环境温度下肝胰脏和白肌ob mRNA的相对表达水平,为探究黄河裸裂尻鱼在青藏高原季节性寒冷环境下的生态适应机制提供科学数据。方法利用RT-PCT、5’-RACE和3’-RACE法获得ob基因全长cDNA序列。通过已知cDNA序列设计半定量RT-PCR和real-time PCR引物,进行表达研究。结果黄河裸裂尻鱼ob基因序列全长为1 337 bp,其中开放阅读框(ORF)长513 bp,编码170个氨基酸。黄河裸裂尻鱼ob mRNA在心脏、肾脏、脂肪、肠、精巢、肝胰脏、鳃、脑和肌肉9个被检组织中均有表达,其中在心脏中表达最强,肌肉组织中表达最弱。栖息水域环境温度下降,将显著抑制黄河裸裂尻鱼肝胰脏和白肌ob mRNA的表达。结论黄河裸裂尻鱼ob基因特殊的组织表达特征可能与其特定组织的能量代谢及其特殊的生物学功能有关。Leptin在黄河裸裂尻鱼能量代谢调节和季节性环境适应方面发挥着重要作用。

Molecular cloning of ob gene in Schizopygopsis pylzovi and its mRNA expression responding to seasonal cold environment at Qinghai-Tibetan Plateau

Objective In order to provide scientific data for understanding the adaptive mechanism of Schizopygop- sis pylzovi to seasonal cold environment at Qinghai-Tibetan Plateau, the obese gene （ob） of Schizopygopsis pylzovi was cloned and its encoding protein leptin was analyzed. Then the expression pattern of the ob mRNA in tissues and the relative expression level of the ob mRNA in hepatopancreas and white muscle of Schizopygopsis pylzovi from habitats of different tem- peratures were assessed. Methods The full-length cDNA of ob gene was cloned by RT-PCT, 5＇-RACE and 3＇-RACE methods. The expression pattern and relative expression level were determined by RT-PCR and real-time PCR. Results The full-length cDNA of ob gene was 1 337 bp, including a 513 bp complete ORF encoding a 170 amino acid peptide. The ob gene was expressed in the nine examined organs, including heart, kidney, fat, intestine, spermary, hepatopancreas, gill, brain and muscle, while strongly expressed in heart and weakly expressed in muscle. The ob gene expression in thehepatopancreas and white muscle of Schizopygopsis pylzovi was suppressed by low temperature. Conclusions The tissue expression pattern of ob gene in Schizopygopsis pylzovi may be related to energy metabolism and biological functions in spe- cific tissues. The encoding protein leptin plays an important role in the regulation of energy metabolism of Schizopygopsis pylzovi, as well as its adaptation to the seasonal cold environment at Qinghai-Tibetan Plateau.