沙门氏菌中dnd基因簇的缺失与异源表达

Deletion of dnd Gene Cluster in Salmonella enterica and Heterogenous Expression

沙门氏菌Salmonella enterica serovar Cerro87是一株从鸡场分离到的菌株,其DNA骨架上的磷硫酰化导致了在高压脉冲电泳过程中DNA降解(DNA degradation,Dnd表型)。本研究采用SacB所介导的负筛选系统,在该菌株中成功缺失了dnd基因簇,构建了突变株XTG103,该突变株不再具有Dnd表型。通过异丙基-β-D硫代半乳糖苷(IPTG)诱导启动子PlacZ的转录可以调控DNA磷硫酰化修饰的dnd基因簇的异源表达。

Salmonella enterica serovar Cerro 87, which was isolated from a commercial egg-producing farm, has a phosphorothioated DNA backbone resulting DNA degradation（Dnd） during the pulsed field gel electrophoresis （PFGE） process. In this research, a gene deletion mutant XTG103 was engineered with the entire dnd gene cluster knocked out by double crossover using vector pKOV-kan, and lost Dnd phenotype correspondingly. We regulated the DNA phosphorothioation by heterogenous expression of dnd gene cluster with an isopropylβ-D-1-thiogalactopyranoside （IgrG） inducible promoter Placz.