水生生物学报2019，Vol.43Issue(2)：272-281,10.DOI:10.7541/2019.034
翘嘴鲌胰岛素样生长因子-Ⅰ的克隆及序列分析
CLONING AND SEQUENCE ANALYSIS OF INSULIN-LIKE GROWTH FACTORI GENE IN TOPMOUTH CULTER (CULTER ALBURNUS BASILEWSKY)
摘要
Abstract
In order to study the effect of IGF-Ⅰ gene on growth traits of topmouth culter (Culter alburnus Basilewsky), IGF-Ⅰ gene was cloned from the genomic DNA of topmouth culter in this study. The gene spanned 14567 bp and comprised five exons and five introns. The five exons of IGF-Ⅰ were 298, 160, 182, 36, and 1360 bp long, respectively. The hypothetical open reading frame of the IGF-Ⅰ cDNA precursor was 486 bp, encoding a putative protein of 161 amino acids. The precursor peptide included a signal peptide (44 amino acids), a mature peptide (70 amino acids), and an E peptide (47 amino acids). The mature peptide comprised four regions: B, C, A, and D. The A and B domains were conserved with six cysteine residues in these two regions to form three disulfide bonds. The B region contained a conserved IGF-Ⅰ receptor recognition sequence (PheB23-TyrB24-PheB25). Analysis of the E peptide showed that IGF-Ⅰ of the topmouth culter was an Ea-2 type. The IGF-Ⅰ amino acid sequence of the topmouth culter had high sequence identity with IGF-Ⅰ proteins from Cyprinidae fish, ranging from 94 to 100％. Phylogenetic analysis of IGF-Ⅰ amino acid sequences showed that IGF-Ⅰ of the topmouth culter does not cluster with the fish from subfamily Cultrinae. IGF-Ⅰ is expressed in all 10 tested tissues with the highest mRNA level in liver, modest level in spleen, heart, testis, and brain, and low level in kidney, gill, stomach, and ovary. The lengths of the four introns of topmouth culter IGF-Ⅰ were 1170, 9364, 251, and 1746 bp, respectively. The variation in the sequence of the introns among species was greater than that of the exons with the highest variation in the third intron. Six microsatellite loci were found in the introns of IGF-Ⅰ with (GATG)5AATAT (ATAG)11 in intron 1, and (CT)8, (TTA)5, (AC)13, (TG)12, and (ATT)5 in intron 2. Four of 6 microsatellite loci were polymorphic, and the genotypes of the four microsatellite loci had no significant correlation with the growth traits of 120 topmouth culter cultured in the same pond (P>0.05). These results provide molecular basis for studying the expression pattern, function and transcriptional regulation of the IGF-Ⅰ gene.关键词
翘嘴鲌/胰岛素样生长因子-Ⅰ基因/内含子/微卫星/序列分析Key words
Culter alburnus/Insulin-like growth factor-Ⅰ gene/Intron/Microsatellite/Sequence analysis分类
生物科学引用本文复制引用
刘士力,程顺,蒋文枰,迟美丽,郑建波,贾永义,赵金良,顾志敏..翘嘴鲌胰岛素样生长因子-Ⅰ的克隆及序列分析[J].水生生物学报,2019,43(2):272-281,10.基金项目
浙江省农业新品种选育重大科技专项(2012C12907-7和2016C02055-1)资助 （2012C12907-7和2016C02055-1）
