6 thoughts on “P19 – Tryon

    1. The most important thing we considered after confirming the presence of two different phage species was which plaque looked the most isolated from nearby plaques so that the likelihood of only one species being present within the plaque was highest. We also wanted a larger plaque, because a small plaque has a chance of actually being just an irregularity in the agar on the plate. The larger plaque we ended up choosing and performing further experiments with happened to be temperate. Thanks for the question.

  1. Hey, good job on the poster and research!

    What are the benefits and consequences of having a temperate phage?

    1. One main benefit of utilizing a temperate phage is due to the integration of the viral genome into the bacterial genome. Modifying the viral genome and then introducing the phage to bacterial hosts allows research into what specific sequences in the viral genome impact bacterial behaviors, such as the transcription of certain genes related to virulence. However, if you are specifically interested in utilizing the phage for phage therapy to combat antibiotic-resistant bacterial infections, a consequence of having a temperate phage is that when the viral genome integrates into the bacteria, that bacteria becomes immune to further infection and thus is not killed until conditions are unfavorable and the lytic cycle is induced through degredation of the repressor protein stopping lytic gene transcription. Thus, while a temperate phage is beneficial for further research of gene impacts upon bacteria, a drawback is the time, money, and effort required to modify the genome to always enter the lytic cycle if one is using the phage for phage therapy.

    1. Thanks for the question! Because a phage undergoing the lysogenic cycle has a repressor protein bound to the prophage (integrated genome) to stop the transcription of lytic genes, to induce the lytic cycle in vitro, this repressor protein must be degraded. This can be done by depriving lysogens of food/nutrients, or by exposing them to toxic chemicals that degrade DNA and the repressor protein. Alternatively, the viral genome can be modified before infection to remove the repressor gene entirely so lytic genes are always expressed.

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