日本血吸虫精氨酸编码基因CDNA的分离和序列分析

【目的】分离和鉴定日本血吸虫(Schistosomajaponicum,S.j)新基因。【方法】应用免疫学方法筛选S.jcDNA文库获得阳性克隆；通过PCR直接序列测定技术，表达序列标签（EST）同源性检索对阳性克隆插入片段进行鉴定；采用亚克隆技术及生物信息学等技术，对获得的日本血吸虫精氨酸酶编码基因序列进行结构与功能的分析。【结果】获得了一个含1061bp外源插入片段的阳性克隆，其cDNA序列含有一个840bp的阅读框，编码279个氨基酸，属精氨酸酶家族，与国际蛋白质库中的酵母、蛙、人和大鼠精氨酸酶序列的同源性分别为44%，50%，51%，53%和54%。【结论】获得了编码日本血吸虫精氨酸酶编码基因全长cDNA，为日本血吸虫精氨酸酶基因功能的研究奠定了基础。

Isolation and SequenceAnalysis of the cDNA Encoding Schistosoma japonicum Arginase

【Objectives】 To isolate and identify novel genes of Schistosomajaponicum(S.j) from cDNA library. 【Methods】 cDNA clones were screened from S.j cDNA library by immunological method, the inserts of positive cDNA clones were identified by PCR directed sequencing and homologous searching of EST, the cDNA sequence encoding S.j arginase was analyzed by the subcloning and bioinformatics. 【Results】 The positive cDNA clone with 1 061 bp insert was isolated from S.j cDNA library, which sequence of the insert included a ORF with 840 bp, and translated into 279 amino acid residues. The deduced protein was similar to the arginase family, the homology at amino acid sequence level was 44%，50%，51%，53% and 54% with schizosacch- aromyces pombe (fission yeast) arginase, xenopus laevis (african clawed frog) arginase, homo sapiens (human) arginase ii precursor and rattus norvegicus (rat) arginase ii precursor respectively. 【Conclusion】 The full-length cDNA sequence encoding Schistosoma japonicum arginase was cloned, which gave the basis for further studying of Schistosoma japonicum arginase.