用于环境污染物遗传毒性评价的重组发光细菌载体的构建

Construction of Recombinate Luminescence Bacteria Vector to Evaluate the Genetoxic of Environment Pollutant

基因重组发光菌在水质毒性的评价中具有重要的作用,本研究从污染物遗传毒性损伤的机制出发,构建2种遗传毒性新型基因重组发光菌载体PUCD-uvrA、PUCD-alkA.用PCR法从大肠杆菌W3110中扩增uvrA、alkA基因,将其与pGEM-T easy载体连接后测序.测序正确的uvrA、alkA片段及PUCD615载体均用BamHⅠ、EcoRⅠ双酶切,连接后电转化导入宿主菌JM109.挑取克隆,提取质粒用PCR鉴定,阳性克隆再进行测序.结果表明,uvrA、alkA基因PCR扩增出的片段为237 bp3、26 bp,测序结果与GenBank中uvrA、alkA序列进行BLAST比对,同源性均为99%,表明扩增序列正确.与PUCD615载体连接后的测序结果表明,uvrA、alkA基因已正确地插入到PUCD615的多克隆位点,方向和读码框正确,2种载体构建成功.通过优化连接及转化条件,可将大片段的PUCD615载体与短片段的插入序列连接成功,构成重组载体.

Recombinate luminescence bacteria have the important role in evaluating water toxicity. Two recombinate luminescence bacteria vectors PUCD-uvrA and PUCD-alkA were constructed to investigate the impaired mechanism of pollutant genetic toxicity. The genes of uvrA and alkA were amplified by PCR from E. coli W3110, sequenced after ligated with pGEM-T easy vector. The PCR products and PUCD615 vector were all digested with BamH Ⅰ , EcoRⅠ , then be linked and imported into JM109 with electrotransformation. Several clones were selected and identificated by PCR and sequencing. The results reviewed that the length of the uvrA and the alkA fragments were 237 bp, 326 bp. When they were sequenced and blasted in GenBank, the homology of sequences reached 99 % indicated the amplified results correct. The results of sequencing ligated with PUCD615 reviewed that the fragments of uvrA and alkA had been inserted into the multiple clone site correctly, the insert direction and reading frame were also exactly. Optimizing the condition of ligation and transformation, the large fragment of PUCD615 and the short inserted sequences can been ligated successfully.