卵形鲳鲹SST1基因的克隆与组织表达

Molecular Cloning and Tissue Distribution of SST1 Gene from Trachinotus ovatus

为了解卵形鲳鲹(Trachinotus ovatus)SST1基因的生物学信息、胚胎发育不同时期的表达水平及其在组织中的表达和分布情况,进而探讨SST1基因可能的生理功能及作用机制。对卵形鲳鯵基因组(登录号:PRJNA574895)中的SST1基因(ID:EVM0001630)进行生物信息学分析,并对其在卵形鲳鯵胚胎发育的不同时期及其在幼鱼不同组织中的表达情况进行定量分析。结果表明,卵形鲳鲹的SST1基因全长1155 bp,开放阅读框序列长1104 bp,共编码368个氨基酸,蛋白分子质量为41.42 ku,理论等电点pI为8.47,属于带正电的疏水性蛋白。SST1蛋白无信号肽序列,亚细胞定位主要于细胞质膜,属于膜蛋白,包含17个磷酸化位点,存在7个跨膜结构域,三维结构主体为7段α-螺旋并列扭曲排列成的一柱状结构。序列比对和系统进化树分析显示,卵形鲳鲹与黄尾鰤和高体鰤共聚于一个分支,氨基酸序列同一性分别为98.39%和98.37%。定量PCR分析结果表明,SST1在卵形鲳鲹胚胎发育的前13个时期微量表达,进入初孵仔期表达量迅速升高。SST1在卵形鲳鲹幼鱼不同组织中的表达量差异极显著,其中在脑组织中表达量最高,其次是卵巢和精巢,在背鳍、皮肤、肌肉等其他11个组织中的表达量相对较低。说明SST1在卵形鲳鲹神经内分泌、性腺发育及生殖细胞发生过程中可能发挥着重要作用。

To understand the biological characteristics of Trachinotus ovatus Somatostatin receptor 1(SST1)gene,the expression level of embryonic development at different stages and its expression and distribution in tissue,the possible physiological function and mechanism of SST1 gene in T.ovatus were further explored.The SST1 gene(ID:EVM 0001630)in the genome of T.ovatus(accession number:PRJNA574895)was analyzed,and its expression at different stages of embryonic development and different tissues of T.ovatus was quantified.The results showed that the full length of T.ovatus SST1 gene was 1155 bp,the open reading frame sequence was 1104 bp,the total of 368 amino acids was encoded and the molecular weight of protein was 41.42 ku with theoretical isoelectric point(pI)of 8.47,which was a positively charged hydrophobic protein.The SST1 protein had no signal peptide sequence,and it was dominant on the cytoplasmic membrane.It belonged to membrane protein,containing 17 phosphorylation sites and 7 transmembrane domains.The main body of its three-dimensional structure was a columnar structure with 7α-helices juxtaposed and twisted.The analysis of sequence alignment and phylogenetic tree showed that the T.ovatus was co-polymerized with Seriola lalandi dorsalis and Seriola dumerili in one clade,with amino acid sequence identities of 98.39%and 98.37%,respectively.The QPCR analysis showed that SST1 was distributed in 13 stages of embryonic development of T.ovatus and highly expressed at the new hatching stage.The expression of SST1 was significantly different in different tissues of young T.ovatus.It was highly expressed in brain,followed by ovary and testis.It was relatively low in dorsal fin,skin,muscle and other 11 tissues.It is suggested that SST1 may play an important role in neuroendocrine,gonadal development and gem cell development.