文蛤防御素基因的克隆及其免疫表达特征研究  

Molecular Cloning and Immune Expressions Regulation of Big Defensin in Meretrix Meretrix

作　　者：周烨 ZHOU Ye(Bureau of Agricultural and rural&Social Development in XingRen Town,Nantong,Jiangsu 226300,China)

机构地区：[1]通州区兴仁镇农业农村和社会事业局,江苏南通226300

出　　处：《水产养殖》2022年第10期13-18,共6页Journal of Aquaculture

基　　金：江苏省水产三新工程项目(D2016-8)。

摘　　要：为探究文蛤(Meretrix meretrix)防御素基因big defensin(MmBD)在其机体免疫防御中的作用,采用RACE技术(cDNA末端快速扩增技术),克隆获得了文蛤MmBD的c DNA全长序列,该基因共758 bp,包含181 bp的5′非翻译区(UTR),214 bp的3′UTR,开放阅读框(ORF)长363 bp,编码氨基酸120 aa。预测的氨基酸序列包含1个信号肽、2个跨膜结构域、高度保守的Cys残基C-X6-C-X3-C-X13(14)-C-X4-C-C和kex2样蛋白酶(KEKR-AV)的裂解位点。组织表达结果表明,MmBD基因在鳃组织中的表达量最高(P<0.05),其次是外套膜和肝胰腺,在足中的表达量最低。不同胚胎发育时期表达结果显示,MmBD基因在D形幼虫期表达量最高(P<0.05),其次是原肠胚期。经高浓度铜离子(Cu^(2+))胁迫后,试验组MmBD基因表达量明显升高,极显著性高于对照组,尤其是36和72 h。指出,文蛤MmBD基因可能在机体免疫中发挥重要功能。In order to investigate the function of Big Defensin in Meretrix meretrix,we cloned the complete cDNA sequence of MmBD by using the rapid amplification of c DNA ends(RACE)approach in this study.The full length of the cloned MmBD cDNA was 758 bp,including a 5′UTR of 181 bp,3′UTR of 214 bp,a 363 bp ORF encoding 120 aas.MmBD posesses one signal peptide,two transmembrane domains,the highly conserved consensus pattern C-X6-C-X3-C-X13(14)-C-X4-C-C and the cleavage site of KEKR-AV.The results of expressions in different tissues showed that MmBD were distributed in all of the examied tissues.MmBD was most highly expresses in the gill(P<0.05),followed by the mantle and hepatopancreas.The expression level of MmBD in foot was lowest.In embryo developmental stages,expression of MmBD was detected highest in D-veligers,followed by the gastrulae.MmBD mRNA was significantly increased under exposure of Cu^(2+)stress.The expressions of MmBD of the experimental group were extremely significant higher than the control group at 36 h and 72 h.These results suggested that MmBD play important roles in immunity system.

关 键 词：文蛤 防御素基因 表达特征 铜离子胁迫 免疫防御 

分 类 号：S917.4[农业科学—水产科学]