凡纳滨对虾细胞因子信号转导负调控因子基因(Lv-SOCS)的克隆及特征分析

Molecular cloning and characteristics of suppressors of cytokine signaling gene( Lv-SOCS) from Pacific white shrimp( Litopenaeus vannamei)

为了探讨凡纳滨对虾细胞因子信号转导负调控因子（SOCS）在病毒引发的免疫应答过程中的潜在作用,本实验根据前期的转录组和表达谱结果提示信息,首次克隆了凡纳滨对虾的SOCS基因（Lv-SOCS,GenBank注册号：KJ000426）,利用在线软件进行了生物信息学分析,运用半定量的方法进行了组织表达分析,并利用实时荧光定量PCR（qPCR）技术分析了该基因在白斑杆状病毒（WSSV）侵染过程中的表达变化特征。结果显示,Lv-SOCS的ORF区1 191 bp,编码397个氨基酸,预测分析显示该基因编码的蛋白质含有1个SH2结构域和1个SOCS-box结构域,组织表达分析表明该基因主要在凡纳滨对虾血细胞、肠道和肝胰腺中表达。在WSSV感染后中晚期（6~48 hpi）,Lv-SOCS可以被显著诱导,在血细胞中呈明显上调表达趋势,表明该基因在一定程度上参与了凡纳滨对虾体内由WSSV引发的先天免疫应答过程,上述结果为进一步研究Lv-SOCS基因在对虾应答病毒侵染过程中的功能和作用机制奠定了基础。

Suppressors of cytokine signaling （SOCS） is an important inhibitor of JAK/STAT signaling pathway, which plays an important role in immunity, growth and development. The results of our previous transcriptome showed that the expression profile of Lv-SOCS fluctuated significantly in response to WSSV infection. It is suggested that Lv-SOCS might be involved in innate immunity in L. vannamei in response to WSSV infection. In this research, the full length cDNA of SOCS gene （ Lv-SOCS, GenBank accession number： KJ000426）was cloned from hemocytes of L. vannamei. Lv-SOCS has a 1 191 bp ORF encoding 397 aa with a predicted molecular weight of 42.30 ku and calculated isoelectric point of 8.62. The SMART online software analysis shows that Lv-SOCS has two functional domains （SH2 domain and SOCS-box）. According to the multiple sequence alignment, Lv-SOCS shows the highest similarity with Marsupenaeus japonicas SOCS which is in a same branch of phylogenetic tree with Lv-SOCS. Semi-quantitative RT-PCR revealed that Lv-SOCS was mainly expressed in hemocytes, intestine and hepatopancreas. The expression of Lv-SOCS could be up-regulated significantly after WSSV infection. The above results give important clues for further study on the function and regulation mechanism of Lv-SOCS in anti-WSSV immune response.