[Isolation of Yersinia pestis plasmids with transposon markers]

Transposons Tn1, Tn7, Tn9, Tn10 have been inserted into each of three known plasmids in Yersinia pestis and have been shown to mutagenize the different plasmid genes. The marked plasmids are shown to be transduced by bacteriophage P1 cml clr 100 ts in intrageneric crosses. The genes of 61-65 Md plasmid were found to be impaired with high frequencies by Tn9 and Tn10 insertions blocking the synthesis of fraction I antigen. The genes are also impaired in course of transduction of transposon marked plasmids.