凡纳滨对虾脂肪酸结合蛋白基因全长cDNA的克隆及序列分析

Cloning and analysis of full length cDNA of intracellular fatty-acid-binding protein in Litopenaeus vannamei

克隆了凡纳滨对虾脂肪酸结合蛋白基因全长cDNA并进行了序列分析。该基因由1042bp的碱基组成,开放阅读框长411bp,编码由136个氨基酸组成的蛋白,基因两翼分别存在113bp(5'端)和518bp(3'段)的非翻译区。聚类分析表明,凡纳滨对虾脂肪酸结合蛋白氨基酸序列与斑节对虾脂肪酸结合蛋白紧密聚为一支,之后聚类顺序依次为刀额新对虾、意大利蜜蜂、斑马鱼、大西洋鲑、鸡、猪和人。通过半定量RT-PCR对该基因在不同组织的表达分析表明,该基因在抗IHHNV对虾肠、胃、肝胰腺和肌肉组织中表达较高,在心肌中表达较低,在眼柄中不表达。比较该基因在抗IHHNV对虾和IHHNV易感对虾心、肝胰腺、肠、胃、眼柄和肌肉组织表达发现,该基因在两种对虾心、肠、胃和肌肉组织中的表达无明显差异,但在肝胰腺中抗IHHNV对虾的表达量明显高于IHHNV易感对虾的表达量,说明该基因参与抗性对虾抑制IHHNV感染的免疫过程。

Full-length cDNA sequence of fatty acid-binding protein was isolated from hepatopancreas of Litopenaeus vannamei.The full-length cDNA sequence of fatty acid-binding protein is 1 042 bp,which contains a 113 bp 5＇-UTR（untranslated region） ,518 bp 3＇-UTR（untranslated region） ,and 411 bp open reading frame （ORF） that encodes 136 amino acid residues.There are typical fatty acid-binding protein domains between 4-26 and 63-79 amino acids residues of Litopenaeus vannamei FABP（LvFABP） ,and these sequences highly conserve in L.vannamei,Metapenaeus ensis,Italian bee,zebra fish,Atlantic salmon,chicken,swine,human.The phylogenetic analysis based on amino acid sequence shows that LvFABP has the highest similarity（98% ） with black tiger shrimp FABP,and has 88% ,57% ,50% ,49% ,51% ,50% ,50% identity with cellular retinoic acid-binding proteins（CRABP） of Metapenaeus ensis,FABP of Italian bee,zebra fish,Atlantic salmon,chicken,swine,human,respectively.The expression of the gene in different tissues was analyzed by semi-quantitative reverse transcription PCR（RT-PCR） ,the result shows that the expression of the gene was higher in intestinal,gastric,hepatopancreas,muscle tissues,and the expression was decreased in myocardium,and undetectable in eyestalk of normal shrimp tissue.Comparing the expression of the gene in myocardium,hepatopancreas,intestinal,gastric,eyestalk,muscle of IHHNV-resistant shrimp to IHHNV-infected shrimp,there was no obvious difference in myocardium,intestinal,gastric and muscle tissues between two kinds of shrimps,but the expression of FABP in hepatopancreas of IHHNV-resistant shrimp is higher than IHHNV-infected shrimp,which showed FABP involves in the immune process inhibiting shrimp from being infected by IHHNV.