扇形游仆虫谷胱甘肽过氧化物酶cDNA的克隆及序列特征分析

采用cDNA 末端快速扩增( rapid amplification of cDNA ends，RACE) 技术，对纤毛虫原生动物扇形游仆虫（Euplotes vannus）GPx cDNA特征进行分析. 克隆到扇形游仆虫GPx cDNA全长序列为672bp，该序列编码182个氨基酸，属硫氧还蛋白超家族，且具有一定的保守性，含有3个催化残基和3个特征性基序．氨基酸序列进化分析结果表明，扇形游仆虫与其他纤毛虫物种同源性较高，亲缘关系较近，研究结果为扇形游仆虫GPx在生态毒理学的应用提供基础信息．

cDNA Cloning and Characterization of Glutathione Peroxidase Gene from Euplotes vannus

Glutathione peroxidase (GPx) has been widely used as a biomarker of environmental stress in ecotoxicology. In this present study, GPx gene in Euplotes vannus was cloned and characterized. Degenerate primers were designed according to the glutathione peroxidase　amino acid sequences in conservative area from similar species. The ful-length cDNA was cloned from　E. vannus using RACE-PCR. Results showed that the complete cDNA in E. vannus is 672bp encoding 182 amino acids and belongs to thioredoxin-like superfamily. Analyses of the derived amino acid sequence data showed that GPx protein contains conservative structure, such as conserved catalytic residues and characteristic motifs, which is typical of glutathione peroxidaseas. Phylogenic analysis of amino acid sequences showed that E. vannus shares higher homology and nearer affinity with other ciliate species.