青蛤(Cyclina sinensis)金属硫蛋白及硫氧还蛋白基因的克隆与表达分析  

EXPRESSION OF METALLOTHIONEIN AND THIOREDOXIN GENE IN CYCLINA SINENSIS EXPOSED TO CADMIUM

作　　者：吕达[1] 罗凯娅[1] 潘宝平[1] 高虹[1] 

机构地区：[1]天津师范大学生命科学学院细胞遗传与分子调控天津市重点实验室,天津300387

出　　处：《海洋与湖沼》2012年第1期47-51,共5页Oceanologia Et Limnologia Sinica

基　　金：天津市科委应用基础与前沿技术重点项目资助,09JCZDJC19300号;天津市科委应用基础研究面上项目资助,10JCYBJC09100号

摘　　要：利用构建的cDNA文库及高通量测序方法,获得金属硫蛋白及硫氧还蛋白基因全长。结果表明,青蛤金属硫蛋白和硫氧还蛋白的cDNA全长分别为776bp和804bp,金属硫蛋白基因编码74个氨基酸,包含7个CXC特征结构;硫氧还蛋白基因编码165氨基酸,包含5个氨基酸构成的活性中心。采用实时定量PCR方法分析了两种基因在Cd2+胁迫下的表达变化,结果显示,金属硫蛋白基因在Cd2+胁迫下6—12hmRNA表达量急剧上升,与对照组有显著性差异(P<0.01)。硫氧还蛋白基因在Cd2+胁迫下mRNA在6h明显升高,在6—24h与对照组出现显著性差异(P<0.05)。说明Cd2+能够诱导青蛤金属硫蛋白和硫氧还蛋白基因表达的时序性升高,二者的转录过程反映了贝类抵御重金属胁迫的分子调控过程。The sequences of metallothionein and thioredoxin of Cyclina sinensis were cloned with the large scale EST sequencing method to built the clams C. sinensis SMART-cDNA library. Real-Time PCR （RT-PCR） technique was used to detect the expression of metallothionein and thioredoxin gene under Cadmium （Cd）. The results showed that the full length cDNA of metallothionein and thioredoxin was 776bp and 804bp respectively. The open reading frame （ORF） of metallothionein encoded 74 amino acids （aa） with 7 typical sequence： CXC. The ORF of thioredoxin encoded 165 amino acids with a typical active position （Trp-Cys-Gly-Pro-Cys.） Real-Time PCR showed that the expression of metallothionein gene significant increased under Cd2＋ stress from 6h to 12h, which was significant different from the control group （P0.01）, then it tend to normal level after 24h. The expression level of thioredoxin gene increased under Cd2＋ intimidated at 6h. And the expression of 12h, 24h was significant different from the control group （P0.05）. Our investigation showed that Cd2＋ could induce the expression of metallothionein and thioredoxin gene, and the transcription reveals the molecular regulation mechanism in the immune defense of Cd2＋ stress in clam of Cyclina sinensis.

关 键 词：青蛤 金属硫蛋白(MTs) 硫氧还蛋白(Trx) 基因表达 

分 类 号：Q789[生物学—分子生物学]