Possible Gene Transfer During Bacterial Predation by Bdellovibrio Bacteriovorus
Paula Elmi
Faculty Advisor: M. O. Martin

     The unique predatory lifestyle of Bdellovibrio bacteriovorus suggests the possibility of gene transfer during predation, as host DNA is internalized and assimilated during this process. Two methods are being used to investigate this phenomenon. A large cosmid clone containing Bdellovibrio chromosomal DNA and a selectable antibiotic resistance marker was introduced into E. coli host cells, and a predation culture with wild type Bdellovibrio was initiated. Addition of the antibiotic should permit only drug resistant Bdellovibrio (those having taken up DNA from the host cells) to multiply. A second approach uses a broad host range plasmid, pJK13, containing the sac B gene from Bacillus subtilis. Bdellovibrio cells harboring this plasmid are sensitive to sucrose; one class of sucrose resistant cells contain insertion sequences within the sac B gene, thereby inactivating it. We hope to identify and characterize insertion elements from Bdellovibrio using this procedure, and determine if they are similar to insertion elements found in E. coli suggesting gene transfer events over long periods of time.