文蛤(Meretrix meretrix)C-型凝集素基因的分子克隆及表达分析  

MOLECULAR CLONE AND EXPRESSION OF C-TYPE LECTIN IN MERETRIX MERETRIX

作　　者：李猛[1] 周素明[1] 刘璐[1] 彭頔[1] 王国良[1] 

机构地区：[1]宁波大学应用海洋生物技术教育部重点实验室,宁波315211

出　　处：《海洋与湖沼》2015年第5期1186-1192,共7页Oceanologia Et Limnologia Sinica

基　　金：教育部长江学者与创新团队项目;IRT0734号;浙江省海水养殖重点科技创新团队项目;2010R50025-08号;宁波市水产病害防控与安全科技创新团队项目;2013B82012号

摘　　要：C-型凝集素是一种重要的模式识别蛋白,本研究以文蛤为材料。利用PCR扩增和RACE技术首次获得了编码文蛤C-型凝集素的基因(Mm-CTL)c DNA序列,全长为1855bp,其开放阅读框为519bp,编码172个氨基酸。Smart软件预测Mm-CTL的糖识别结构域(CRD)从第34个氨基酸到第168个氨基酸。BLASTP序列相似性分析显示,Mm-CTL与大竹蛏氨基酸序列同源性最高,相似性为56.5%,与其它无脊椎动物的相似性为13.5%—23.9%。系统进化树分析与同源分析结果一致,其中Mm-CTL与双壳类C-型凝集素聚在一起,与大竹蛏亲缘性最近。环境胁迫实验显示,溶藻弧菌感染6h时Mm-CTL表达量明显上升,在12h时达到最高值,随后有所下降。盐度胁迫时Mm-CTL在盐度5时表达量相对较低,在盐度10—20中的表达量相对较高。温度胁迫时Mm-CTL在35°C时表达量相对最高,10°C时表达量明显较低。研究结果表明,文蛤应对环境因子影响可通过调节Mm-CTL的表达来应答免疫反应。本研究将为贝类先天性免疫因子研究以及病害的防控奠定基础。The C-type lectin is one of the most important pattern recognition receptors. In present study, a C-type lectin was cloned from Meretrix meretrix（Mm-CTL） for the first time using degenerated PCR and rapid amplification of complementary DNA ends（RACE） method. The full length of the Mm-CTL c DNA was 1855 bp containing a 519-bp open reading frame（ORF） encoding a 172-amino-acid polypeptide. Prediction of protein domains revealed that the Mm-CTL contain a typical carbohydrate recognition domain（CRD） that ranged 34 th to 168 th amino acid. BLASTP analysis showed that the Mm-CTL shared 56.5% identity with the ortholog in Solen grandis, and 13.5%—23.9% with other invertebrate orthologs. Mm-CTL is distinctly clustered with mollusk as expected in phylogenetic analysis. After Vibrio alginolyticus challenge, the Mm-CTL m RNA was induced significantly in 6h post challenge, and its expression peaked in 12 h. Moreover, the Mm-CTL expression reduced in salinity 5 compared to that in salinity 10—20. In a thermal stress, the Mm-CTL expression was down-regulated at 10°C, whilst increased at 35°C. Therefore, the expression of Mm-CTL might response to bacterial infections or environmental stress. The findings may help understanding innate immune factor in molluscs for disease prevention.

关 键 词：文蛤 C-型凝集素 基因克隆 生物信息学 环境因子 

分 类 号：S917[农业科学—水产科学]