中华鲟神经内分泌多肽7B2基因克隆及组织特异性表达

Cloning and expression analysis of a neuroendocrine secretory protein 7B2 in Acipenser sinensis

以中华鲟(Acipenser sinensis)脑垂体总RNA为模板,采用RT-PCR和RACE方法,获得中华鲟神经内分泌多肽(7B2)基因的3个重叠片段,测序后拼接得到986 bp全长基因序列,其中包括5'端非翻译区(5′-UTR)14 bp、3′端非翻译区(3-′UTR)261 bp和开放阅读框711 bp。翻译编码236个氨基酸。其中前43个氨基酸为7B2的信号肽。经BLAST比对发现中华鲟7B2蛋白的同源性与斑马鱼(Danio rerio)的相似性最高为82%。系统发育分析表明,中华鲟与斑马鱼亲缘关系最近。半定量RT-PCR分析表明:在脑中7B2 mRNA表达量最高,心脏、性腺、胰等组织中表达次之,肠、肾、皮肤等组织中少量表达,肝和鳃几乎不表达。

In order to clone full-length 7B2 gene and characterize its＇ tissue expression profile in Chinese sturgeon（Acipenser sinensis）,RT-PCR and rapid-amplification of cDNA ends（RACE） were adopted to obtain full-length cDNA.A full-length 986 bp cDNA sequence in A.sinensis was cloned,including a 711 bp complete ORF encoding a 236 amino acids peptide,a 14 bp long 5′-untranslate region and a 261 bp long 3′-untranslate region.The first 43 of the 236 amino acids were 7B2 signal peptide.The 7B2 in A.sinens showed high similarity to that of Danio rerio.The protein analysis showed that the A.sinensis 7B2 had the closest relationship with the D.rerio.Futhermore,7B2 mRNA tissue expressed profile was assessed by semi-quantitative RT-PCR.In the nine examined tissues,the 7B2 gene was expressed strongly in brain,weakly in heart,gonad and pancreas,and little in kidney,bowel and skin,but hardly expressed in gill and liver.