Event Title

Regulation of Expression of the LIP1 Gene in the Bacterium Photorhabdus Temperata

Presenter Information

Bryan Reddick, Minnesota State University, Mankato

Location

CSU 203

Start Date

9-4-2012 1:00 PM

End Date

9-4-2012 2:00 PM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Christopher Conlin

Mentor's Department

Biological Sciences

Mentor's College

Science, Engineering and Technology

Description

The lip1 gene found in the bacterium Photorhabdus temperata, an insect pathogen, is a member of a family of closely related esterase’s found in many gram negative bacteria including apeE from Salmonella typhirmurium. Their function is largely unknown. However, we do know apeE is regulated by phosphate starvation. We have begun to study the regulation of gene expression in the lip1 gene. By inserting the lip1 gene into chromosomal DNA of Salmonella we were able to test its regulation. Results indicate that unlike apeE, lip1 is not regulated by limiting phosphate levels. Furthermore, during growth phase there was a thirty fold increase from exponential phase to stationary phase indicating the lip1 gene is expressed during stationary phase. The rpoS gene is an alternative sigma factor known to regulate a number of genes whose expression increases in stationary phase. The results from Salmonella with the rpoS mutation displayed a six fold reduction of expression when compared to the wild type in stationary phase indicating regulation by rpoS. To confirm these results in Photorhabdus temperata, we are moving the reporter system into the original host and assaying at different times during growth phase.