Characterizing Heme-Induced Genes of Sodalis glossinidius

Over time, bacteria have evolved to live in nearly every environment that exists on this planet, including in symbiotic relationships with other species. One such relationship of interest is between the tsetse fly and its endosymbiont Sodalis glossinidius (Sodalis), which lives in the gut of the fly. Living in the gut of the fly is an extreme environment because the tsetse fly survives on blood meals, so when the fly consumes a blood meal its gut is flooded with toxic levels of heme, a component of blood. However, Sodalis is able to survive these toxic levels of heme through gene regulation and production of certain proteins that help it survive. This work has been done to determine which genes allow Sodalis to survive in a high-heme environment and to further characterize their role in heme survival. One Sodalis gene, SGP2_0013, was tested by creating a Sodalis knockout strain (URSOD30), which was studied using heme growth and survival assays as well as with genome sequencing. Another Sodalis mutant strain (URSOD25), lacking a functional uspA gene, had been made previously and was tested in a heme growth assay to determine the gene’s role in heme resistance. And to further characterize the Sodalis uspA gene, a ΔuspA E. coli mutant with a plasmid carrying the Sodalis uspA gene (JW34621/pKEW2) underwent a variety of oxidative stress tests