摘要
将斜卧青霉JUA - 10染色体DNA的BamHI或PstI片段连接到大肠杆菌的启动子探针型载体pSUPV4上 ,克隆了 7个不同大小的具有启动子功能的DNA片段。卡那霉素抗性试验表明 ,含重组质粒的大肠杆菌均能耐受 10 0 μg/ml以上的卡那霉素 ,最高可达 110 0 μg/ml。说明斜卧青霉的某些DNA片段能在大肠杆菌中有效地启动基因表达。取抗性水平最高的 pPdsuI进一步进行限制酶谱分析 ,表明插入片段的分子量为 2 .4Kb。
Seven promoter-functional DNA fragments of different sizes have been cloned from Penicillium decumbens JUA-10 by using promoter-detecting plasmid pSUPV4 as vector and E.coli JM109 as host strain.The result of the experiment on kanamysin resistance indicaties that all of the seven E.coli Kan.transformants are able to grow in the medium containing kanamysin of 100 μg/ml～1100μg/ml,which demonstrates that some promoter-functional DNA fragments from Penicillium decumbens are active in E.coli .A further Restriction enzyme analysis of plasmid pPdsu1 with the highest level of resistance to kanamysin is conducted and the result indicated that the length of the fragment inserted into pPdsu1 is of 2.4kb.Result of Southem hybridization analysis indicates that this DNA fragment originally comes from Penicillium decumbens chromosomal DNA.
