厚壳贻贝抗菌肽mytilin和myticin的cDNA基因的克隆与序列分析  

cDNA clone and sequence analysis of mytilin and myticin from Mytilus coruscus

作　　者：廖智[1] 刘梅[1] 王日昕[1] 武梅[1] 杨丽佳[1] 鲁涛[1] 徐田军[1] 石戈[1] 

机构地区：[1]浙江海洋学院海洋科学学院,海洋生物资源和分子工程实验室,浙江舟山316004

出　　处：《水产学报》2010年第7期1025-1033,共9页Journal of Fisheries of China

基　　金：国家科技支撑计划(2007BAD43B08);农业部海洋与河口渔业资源及生态重点开放实验室开放课题(开-09-10);浙江省科技厅重大项目(2007C02001);浙江省科技厅面上科研农业项目(2008C22026;2009C32016);舟山市科技局项目(Y20082080);浙江省大学生科技创新项目;浙江省大学生创新创业孵化项目

摘　　要：抗菌肽是贻贝免疫系统中的一个重要组成部分,也是目前海洋生物抗菌肽研究的重要内容。在贻贝抗菌肽家族中,mytilin和myticin是目前贻贝抗菌肽研究中发现成员最多,丰度最高的两个家族,在贻贝免疫系统中占有重要的地位。为了解厚壳贻贝抗菌肽mytilin和myticin的基因组成及其多样性机制,通过设计特异性引物,以厚壳贻贝血细胞cDNA文库为模板进行PCR扩增以筛选文库,共克隆到8条mytilin的同源cDNA序列和9条myticin的同源cDNA序列,并对其基因序列及推导的氨基酸序列进行了序列比对和变异位点初步分析。上述研究为将来深入研究厚壳贻贝的免疫机制及筛选具有开发价值的抗菌肽分子奠定了理论基础。Antimicrobial peptides not only represent an important component of innate host defense against microbial colonization and a link between innate and adaptive immunity,but also form a foundation for the development of new therapeutic agents.As the most important antimicrobial peptide families in mussel,mytilin and myticin contain many members referred to as isofoms and have the highest abundance in mussel serum,which means these two families play a key role in mussel innate immunity.To investigate the molecular diversity and the sequence characterization of mytilin and myticin from Mytilus coruscus,the cDNA of mytilin and myticin were cloned respectively by PCR method using M.coruscus hemocyte cDNA library as template.Eight deferent mytilin cDNAs and nine deferent myticin cDNAs were cloned from M.coruscus hemocyte cDNA library,respectively.The precursor translated from mytilin cDNA contains a putative signal peptide of 22 residues,a processing peptide sequence of 34 amino acids,and a C-terminal extension of 46 residues rich in acidic residues; while the precursor translated from myticin cDNA contains a putative signal peptide of 20 residues,a processing peptide sequence of 40 amino acids,and a C-terminal extension of 37 residues.Both mytilin and myticin of M.coruscus are characterized by abundant cationic amino acids and eight cysteins which formed four disulfides.Sequence analysis of the coding frame showed that the variation loci of these two kinds of antimicrobial peptide mainly occurred on mature peptide region,which might result from direct interaction of these peptides with the surrounding pathogens in the changing environment and thus become a likely cause of molecular adaptation of certain amino acid sites in mytilin and myticin variants.This study laid the foundation for intensive study on immune mechanisms as well as screening antimicrobial peptide molecules from M.coruscu antimicrobial peptides.

关 键 词：厚壳贻贝 抗菌肽 mytilin myticin CDNA 

分 类 号：Q785[生物学—分子生物学] S917[农业科学—水产科学]