银鲫apelin基因的克隆、组织表达谱和摄食关系的初步研究

apelin是一种参与哺乳动物和鱼类摄食调控的重要神经肽。为了更好地研究apelin在银鲫(Carassius auratus gibelio)上的摄食调控作用,本试验采用RACE技术首次获得了银鲫apelin的cDNA全长序列,并通过实时荧光定量PCR(RT-PCR)技术检测了apelin基因在各组织的表达情况以及餐前餐后和禁食对其表达量的影响。结果显示银鲫apelin全长cDNA序列长度为1082 bp,其中5’非编码区(5’-UTR)的长度为114 bp,3’非编码区(3’-UTR)的长度为734 bp,开放阅读框(open reading frame,ORF)的长度为234 bp。银鲫apelin基因的ORF区编码77个氨基酸,前22个氨基酸为信号肽。apelin基因在银鲫21个组织中普遍表达,特别是在下丘脑中表达量最高。在餐前餐后的试验中,银鲫下丘脑apelin基因在餐后表达量显著下降(p<0.05);在禁食试验中,禁食组下丘脑apelin基因的表达量在第5天显著升高(p<0.05),第7天极显著升高(p<0.01),复投喂后,apelin基因的表达量在第9天、第11天、第14天极显著降低(p<0.01)。综上所述,apelin基因可能是银鲫的诱食因子,在其摄食调控起到一定的作用。

Cloning,Expression Profiling and Feeding Relationship of the apelin Gene in Gibel Carp(Carassius auratus gibelio)

Apelin,an important neuropeptide,is involved in the regulation of feeding in mammals and fish.To better understand the regulation mechanism of apelin on feeding in Carassius auratus gibelio,we obtained the full-length cDNA sequence of apelin in Carassius auratus gibelio using RACE technology for the first time in our study.Subsequently,we investigated the distribution of apelin mRNA,and determined the expression profile of apelin during periprandial,postprandial changes and fasting of the hypothalamus using real-time fluore-scence quantitative PCR(RT-PCR).The results showed that apelin full-length cDNA sequences was 1082 bp in length,and contained a 5’-untranslated region(5’-UTR)of 114 bp,a 3’-untranslated region(3’-UTR)of 734 bp and a open reading frame(ORF)of 234 bp.The ORF of gibel carp apelin gene encoded the peptides of 77 amino acid and the first 22 amino acids were signal peptides.apelin mRNAs were ubiquitously expressed in various tissues,the highest mRNA levels were observed in the hypothalamus.In the Postprandial study,the expression level of apelin gene showed a significant decrease in gibel carp hypothalamus after meal(p<0.05).In the fasting study,the expression of apelin gene was increased significantly on the 5 th day(p<0.05)in the fasting group,and the same result was observed on the 7 th day(p<0.01).However,after refeeding,the expression of apelin gene was decreased significantly on the 9 th,11 th and 14 th days(p<0.01).The results indicated that apelin had an orexigenic character in Carassius auratus gibelio and might play a role in feeding regulation in fish.