草鱼LPL基因的表达及饥饿和再投喂对其影响

Study on the LPL gene expression and the influcence of fasting and refeeding on it in grass carp,Ctenopharyngodon idellas

获得了草鱼脂蛋白脂酶(lipoprotein lipase,LPL)部分cDNA序列(GenBank注册号为FJ612596),并进行了序列同源性分析;采用半定量反转录聚合酶链式反应(SQ-RT-PCR)方法,检测了LPL基因在草鱼不同组织和不同发育阶段脂肪细胞中的表达状况;研究了饥饿和再投喂对草鱼肝胰脏LPL基因表达的影响。结果显示,所获得的草鱼LPL部分cDNA序列长度为360bp,与其它物种的同源性为70%～89%;LPL基因在肝胰脏、肌肉、心脏、鳃、腹腔脂肪组织中均表达,其中在腹腔脂肪组织中表达丰度最高,在鳃中表达丰度最低;在成熟脂肪细胞中的表达丰度显著高于基质脉管组分(stromal vascular fraction,SVF)细胞;草鱼LPL基因表达水平在饥饿48h后显著升高,再次投喂后12h,回复到0h的表达水平。研究表明,草鱼LPL在不同组织及脂肪细胞分化的起始和终末阶段均有表达,显示其在草鱼不同组织和脂肪细胞分化中具有重要作用,同时,其表达水平受营养状况的调控。论文首次克隆得到草鱼LPL基因部分cDNA序列,并对其进行了表达分析,研究结果可为LPL在鱼类脂质代谢中的作用研究提供参考和依据。

For the better understanding about the mechanism of lipid metabolism at the molecular level in grass carp Ctenopharyngodon idellas,the partial cDNA sequence of lipoprotein lipase （LPL） gene was cloned （GenBank accession number FJ612596）,and its expression in different organs,adipocytes,as well as the influence of fasting and refeeding on it in hepatopancrease were studied by means of semi-quantitative （SQ-RT-PCR . The results showed that the obtained cDNA sequence was 360 bp in length,and the homology is 70%-89% with other species. LPL gene is widely expressed in hepatopancreas,muscle,heart,gill,intrapaneal fat body （IPF）,mature adipocytes and stromal vascular fraction （SVF） cells ,with the highest expression level in IPF,lowest one in gill among the organs （P 〈0.05）,and higher level in mature adipocytes,compared to SVF cells （P〈0.05）. On the other hand,LPL gene expression level significantly increased in hepatopancreas after 48 h fasting and retrieved to the same level as 0 h after 12 h refeeding （P〈0.05）. It could be concluded that LPL gene is wildely expressed in various organs and at the initiation and final differentiation stage of adipocyte,regulated by the energy expenditure status,which implies its important role in lipid metabolism in grass carp. The further study on the modification mechanism of LPL gene is required in fish.