凡纳滨对虾MT基因序列及其在卵巢发育和低温胁迫中的表达分析

SEQUENCE AND EXPRESSION ANALYSIS OF METALLOTHIONEIN FROM LITOPENAEUS VANNMEI

在低温处理仔虾全长cDNA文库的筛选测序中,获得凡纳滨对虾(Litopenaeus vannmei)金属硫蛋白基因全长cDNA序列,该序列含有425个碱基,包含177 bp开放阅读框,上游98 bp的非编码区及下游150 bp的非编码区,编码58个氨基酸,其中半胱氨酸含量丰富,富含金属硫蛋白典型的Cys-X(1-3)-Cys结构。多序列比对表明,凡纳滨对虾MT蛋白序列与美洲螯龙虾(Homarus americanus)MT蛋白序列具最高同源性72.4%。Real-time PCR结果表明,凡纳滨对虾MT基因在卵巢组织中呈优势表达,在不同发育期的卵巢中的表达量都很高,在低温处理凡纳滨对虾肝胰腺组织中上调表达。实验所得结果为研究凡纳滨对虾金属硫蛋白基因在生殖发育和低温应激中的功能提供了参考。

A 425 bp Litopenaeus vannmei Metallothionein gene（LvMT） cDNA sequence was got from the SMART cDNA library of low temperature treated young Litopenaeus vannmei.The cDNA contained a 98 bp 5′ terminal untranslated region（UTR）,a 150 bp 3′ terminal UTR and a 177 bp open reading frame（ORF） sequence that encoded 58 amino acids（AA）.The deduced amino acids sequence was rich in cysteine and Cys-X（1-3）-Cys structure which was classic structure in MT genes.Multiple alignment showed high identity of MT gene from different species,and the identity of Litopenaeus vannmei and Homarus americanus MT was up to 72.4%.The realtime PCR analysis revealed that LvMT mRNA mainly expressed in ovary and high level expression was found in different ovary development stages.Furthermore,the expression of LvMT mRNA was up-regulated in the low temperature treated Litopenaeus vannmei hepatopancreas.The data is useful for the function analysis of LvMT in ovary development and low temperature stress.