Systematic Analysis of Gene Toxicity in Mycobacteriophage Bromden

Abstract

With an estimated population of 10 31 individuals, Bacteriophages are the most abundant form of life present on this planet. This abundance can be observed in the diversity of their genome: over 70% of genes present in newly sequenced bacteriophages remain without an unknown function. To reduce this gap in knowledge, I screened each gene in the phage Bromden genome for cytotoxicity when expressed individually in its host, Mycobacterium smegmatis. To perform this screen, I created a plasmid library that allows the inducible expression of each Bromden gene. I found 42 genes affecting the growth of the host bacteria which will be pursued in the laboratory to understand the underlying mechanism behind the toxic phenotype. Two genes were found to be extremely toxic, and I describe additional experiments I am pursuing to study them. In addition, I screened the uOttawa Mycobacteriophage library for host range capabilities onto Mycobacterium tuberculosis.