糖多孢菌属菌株的体内转座诱变系统
In vivo transposition mutagenesis system of Saccharopolyspora

为实现糖多孢菌的体内转座诱变，采用刺糖多孢菌的强启动子促进Tn5转座酶基因tnp(5)的表达，优化链霉菌高效转座质粒pHL734，构建了转座质粒pJTn1、pJTn2、pJTn3、pJTn4、pJTn5、pJTn6。结果显示：pJTn1~pJTn6系列转座质粒均可在红色糖多孢菌中高效转座；pJTn1和pJTn5可在刺糖多孢菌中进行转座，获得31个刺糖多孢菌转座突变株；其中30个菌株的基因组中检测到标准的Tn5转座，8个突变株的多杀菌素产量显著降低。表明pJTn系列转座质粒可作为糖多孢菌的体内转座诱变工具，为抗生素的产量调控研究和高产育种靶标基因筛选提供理论依据。
To establish an in vivo transposition mutagenesis system of Saccharopolyspora,the transposition plasmids pJTn1 pJTn6 were constructed by enhancing the expression of Tn5 transposase gene tnp (5) with strong promoters originated from Sa. spinosa and optimizing the Streptomyces Tn5 based transposition plasmid pHL734. The results showed that plasmids pJTn1-pJTn6 transposed efficiently in Sa. erythraea. Plasmid pJTn1 and pJTn5 worked well in Sa.spinosa. Canonical events of Tn5 transposition were detected on 30 genomes out of 31 Sa.spinosa transposition mutants. There was a significant decrease in the yield of spinosad in eight mutants. It demonstrated that the pJTn plasmids are valuable tools for the transposition mutagenesis in the genus of Saccharopolyspora,which will facilitate studying the regulation of spinosad production and screening target genes for the high yield breeding