盐地碱蓬AGO蛋白基因家族的分离及表达分析

AGO蛋白(Argonature protein)作为RNA诱导沉默复合物的核心元件,在植物的非生物胁迫过程中发挥着重要作用。以前期获得的盐地碱蓬转录组数据为基础,开展了针对盐地碱蓬(Suaeda salsa)AGO蛋白的生物信息学及盐胁迫下的表达规律研究。采用RACE技术克隆2个AGO基因家族成员(SsAGO1、SsAGO16)的cDNA全长序列,并对其蛋白结构、进化关系、表达模式等进行分析。结果表明:盐地碱蓬2类AGO蛋白家族成员基因长度分别为3 212 bp和3 766 bp,编码的蛋白均是一个无跨膜结构域、无信号肽的亲水性蛋白,α-螺旋散布于每个蛋白质的整体结构中;SsAGO1和SsAGO16都含有一个未知的结构域DUF1785,除此之外,SsAGO1还含有PAZ和PIWI两个特征结构域,而SsAGO16仅含有PIWI结构域,SsAGO1和SsAGO16亲缘关系较远,且具有不同的时空表达模式。首次从盐地碱蓬鉴定了AGO蛋白基因并进行了盐胁迫下的表达规律分析,为研究AGO蛋白家族在盐生植物耐盐生理过程中的作用奠定了基础。     

Characterization of defensin gene from abalone Haliotis discus hannai and its deduced protein

Defensin is one of preserved ancient host defensive materials formed in biological evolution. As a regulator and effector molecule, it is very important in animals' acquired immune system. This paper reports the defensin gene from the mixed liver and kidney cDNA library of abalone Haliotis discus hannai Ino. Sequence analysis shows that the gene sequence of full-length cDNA encodes 42 mature peptides (including six Cys), molecular weight of 4 323 Da, and pI of 8.02. Amino acid sequence homology analysis shows that the peptides are highly similar (70% in common) to other insects defensin. Because of a typical insect-defensin structural character of mature peptide in the secondary structure, the polypeptide named Haliotis discus defensin (hd-def), a novel of antimicrobial peptides, belongs to insects defensin subfamily. The RT-PCR result of Haliotis discus defensin shows that the gene can be expressed only in the hepatopancreas by Gram-negative and positive bacteria stimulation, which is ascribed to inducible expression. Therefore, it is revealed that the Haliotis discus defensin gene expression was related to the antibacterial infection of Haliotis discus hannai Ino.     

皱纹盘鲍肝、肾表达序列标签及神经肽Y(NPY)受体基因的克隆与分析

通过构建皱纹盘鲍(Haliotis discus Hannai)cDNA文库并进行大规模测序,获得了1282条高质量的ESTs序列,对这些序列进行拼接,获得了包括650条序列在内的244组片段重叠群(Contigs)和632个单一序列(Singletons).使用BlastX软件对876个Unigenes(Uniger...     

Characterization of defensin gene from abalone <Emphasis Type="Italic">Haliotis discus hannai</Emphasis> and its deduced protein

Defensin is one of preserved ancient host defensive materials formed in biological evolution. As a regulator and effector molecule, it is very important in animals＇ acquired immune system. This paper reports the defensin gene from the mixed liver and kidney cDNA library of abalone Haliotis discus hannai Ino. Sequence analysis shows that the gene sequence of full-length cDNA encodes 42 mature peptides （including six Cys）, molecular weight of 4 323 Da, and pI of 8.02. Amino acid sequence homology analysis shows that the peptides are highly similar （70% in common） to other insects defensin. Because of a typical insect-defensin structural character of mature peptide in the secondary structure, the polypeptide named Haliotis discus defensin （hd-def）, a novel of antimicrobial peptides, belongs to insects defensin subfamily. The RT-PCR result of Haliotis discus defensin shows that the gene can be expressed only in the hepatopancreas by Gram-negative and positive bacteria stimulation, which is ascribed to inducible expression. Therefore, it is revealed that the Haliotis discus defensin gene expression was related to the antibacterial infection of Haliotis discus hannai Ino.