宿主菌株及培养温度对乙型脑炎病毒cDNA克隆稳定性的影响

EFFECTS OF ESCHERICHIA COLI STRAINS AND TEMPERATURES ON STABILITY OF JAPANESE ENCEPHALITIS VIRUS CDNA CLONES

本研究旨在探讨宿主菌株及培养温度对JEV cDNA克隆在宿主菌中稳定性的影响。选取猪源乙型脑炎病毒基因Ⅰ型HEN0701株和基因Ⅲ型SH0601株为研究对象,分别将两毒株基因组克隆中不稳定的质粒转化不同大肠杆菌菌株,并改变转化菌的培养温度,将不同条件下培养的质粒进行序列分析。试验结果表明,不同宿主菌株对重组质粒不稳定性的影响不显著;低温培养可以克服克隆序列的不稳定。对获得的突变质粒的分析结果显示,基因组5'端的3个起始密码子和E蛋白可能与质粒的不稳定性相关。

To illustrate the effects of host strains and growth temperatures on genetic stability of Japanese encephalitis virus （JEV） cDNA clones, plasmids pTSHC1 from JEV genotype Ⅲ（GⅢ） strain SH0601 and pTHENC1 from GI strain HEN0701 were transformed into different E. coli strains when grown at different temperatures. Both plasmids were unstable in host bacteria grown at 37 ℃ . At lower temperature, both plasmids propagated well in different hosts. However, some mutants with deletion and insertion of heteromorphic segments provided good growth for plasmids at 37℃ The sequence analysis of mutant plasmids showed that three start codons located at 5＇ terminus of genome and E gene might be relevant to unstable growth of plasmids.