褶牡蛎金属硫蛋白基因的克隆及组织表达分析

发布时间：2018-06-23 18:01

本文选题：褶牡蛎 + 金属硫蛋白　；参考：《水产科学》2017年05期

【摘要】：金属硫蛋白是一类广泛存在于生物体中的低分子质量、富含半胱氨酸、高度诱导性的内源金属结合蛋白。采用RACE技术,首次获得了褶牡蛎金属硫蛋白基因的全长cDNA序列。该序列全长500bp,由长54bp的5′非翻译区,122bp的3′非翻译区和324bp的开放阅读框组成,共编码107个氨基酸。该蛋白序列中半胱氨酸含量丰富(28%),不含芳香族氨基酸,富含金属硫蛋白典型的Cys-X(1-3)-Cys结构,存在软体动物等无脊椎动物金属硫蛋白特征序列,是金属硫蛋白家族成员。荧光定量PCR法,测定褶牡蛎体内3种组织(内脏团、鳃、外套膜)中金属硫蛋白mRNA组织特异性表达以及重金属(Cd~(2+)、Zn~(2+))慢毒胁迫效应。结果表明,金属硫蛋白mRNA在褶牡蛎内脏团中相对表达量最高;褶牡蛎内脏团金属硫蛋白mRNA表达量与重金属胁迫时间呈现出一定时间效应关系,从胁迫开始至7d表现为正调,而7~10d开始为负调,Cd~(2+)胁迫和Zn~(2+)联合Cd~(2+)胁迫下金属硫蛋白mRNA表达量显著增加,最大表达量为对照组的42.5倍(Cd),Zn~(2+)联合Cd~(2+)胁迫表现为拮抗作用。本试验结果为生产实践上在多种重金属污染下应用金属硫蛋白作为生物标志物监测水域污染状况,保护水生生态环境提供了依据。
[Abstract]:Metallothionein is a class of low molecular weight, cysteine-rich and highly inducible endogenous metal-binding proteins widely found in organisms. The full-length cDNA sequence of metallothionein gene was obtained by race for the first time. The 5'untranslated region (5'untranslated region) of 54bp and the open reading frame (ORAF) of 324bp are composed of 5'untranslated region (5'untranslated region) of 54bp and an open reading frame (ORAF) of 324bp, encoding 107 amino acids. The protein sequence is rich in cysteine content (28%), does not contain aromatic amino acids, and is rich in metallothionein typical Cys-X (1-3) -Cys structure. It has the characteristic sequence of metallothionein in invertebrates such as molluscs, and is a member of metallothionein family. The specific expression of metallothionein mRNA in three tissues (visceral mass, Gill and outer membrane) and the slow toxicity of heavy metal (Cd2) Zn2 in oyster were determined by fluorescence quantitative polymerase chain reaction (FQ-PCR). The results showed that the relative expression of metallothionein mRNA was the highest in the visceral mass of oyster, and the expression of metallothionein mRNA in the visceral mass of oyster showed a time-dependent relationship with the time of heavy metal stress, which was positive from the beginning of stress to 7 days. The expression of metallothionein mRNA was significantly increased under the stress of Zn ~ (2) and CD ~ (2) + CD ~ (2). The maximum expression of metallothionein mRNA was 42.5 times (CD) ~ (2) ~ (2) + CD ~ (2) + CD ~ (2) stress. The results provided a basis for the application of metallothionein as a biomarker to monitor the water pollution and protect the aquatic ecological environment in the production practice under the pollution of many heavy metals.
【作者单位】：国家海洋局第三海洋研究所;厦门大学;国家海洋局海洋生物资源综合利用工程技术研究中心;
【基金】：厦门海洋研究开发院共建项目(K150104) 国家海洋局第三海洋研究所基本科研业务费专项资金资助项目(海三科2013014)
【分类号】：S917.4;X834

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