Detection of Phage DNA in the Hosts Genome during Lysogeny

Mycobacteriophages (phage) are viruses that need a bacterial host cell to reproduce. They infect the cell with its genome to “hijack” the cellular machinery. It then uses the host’s machinery to carry out its life cycle. Some Phages can enter a stage of life where it begins to coexist with the host. This is called lysogeny. The phage Sedona was discovered in 2008 at Salish Kootenai College and has not been previously characterized. My research is focused on the genetic characteristics of the Sedona Lysogen. A growth curve shows that the Sedona Lysogen grows very rapidly after an initial delay, as compared to non-Lysogenic Mycobacterium smegmatis mc² 155 (M.s.). DNA was isolated from the lysogen and phage. Primers were designed around the phage attP integration site based on other phages. PCR was done on phage DNA with positive results; which means detection of the attP site in the Sedona phage genome is possible. Primers were also designed around the M.s. attB integration site and PCR will be done. If those results are positive, primers will be mixed to detect the integration site in the Lysogen genome. This site is created from half of the phage site and half of the bacterial site; it is recombined to integrate the phage. After verification of Sedona integration into the hosts genome, it will be subjected to different stressful conditions to find out what will make the virus return to the lytic life cycle.