9 thoughts on “P46 – Singh

  1. What are the relevant differences between myoviridae and siphoviridae when infection and life cycles are concerned?

    1. Hey Cullen! Unfortunately, I do not exactly know the differences between myoviridae and siphoviridae in specific regards to infection and life cycles. However, I do know the structural differences, in that myoviridae phages have shorter tails than siphoviridae, and siphoviridae can have longer, more elongated heads (kind of looking like a corndog). In regards to our phage, we actually adopted another lab group’s phage to experiment on, and their phage turned out to be a corndog phage!

    1. Hey Ty! We hypothesized about the potential repressor mutation because our phage that originally presented itself as temperate later on presented itself to be lytic! So, the repressor gene is expressed in temperate phages, as it blocks the translation of lytic genes in the lysogenic life cycle. So the first pictured result, representing plaques indicative of a temperate phage led us to believe that the phage had a repressor gene encoded for in its genome. But for figures 3A and 3B, then figure 4, the plaques forming were representative of a lytic phage, so we figured that the repressor gene must have mutated, so that the lytic genes were no longer being blocked from being transcribed. We figured that to be the most plausible explanation, as the genome for our phage was still the same genome, it’s not like it was entirely different!

  2. Hi Aarushi! Great job on both your poster and presentation. Can you explain a bit more what a titer assay spot test entails?

    1. Hey Aubrey! Thank you so much! So a titer spot test essentially gets us to look at all of the dilutions (10^-1 through 10^-8; the dilutions are so that we can make sure we are isolating and studying only one phage species) for our high titer lysate, which is a liquid with our specific phage that we are studying. From looking at all of the dilutions, we can determine which dilution has a countable number of plaques where we can try to calculate the titer for our high titer lysate. As for the calculated titer, that tells us how much concentration of phage we have!

  3. Can you elaborate on what you were hoping to find and what methods you used to obtain your data?

    1. Hey Angel! Yes, of course! We set out hoping to find a mycobacteriophage, first and foremost. We did not really have a specific goal as to what type of phage we wanted to find, be it lytic or temperate. But to try and isolate our phage, we started with collecting a soil sample and enriching it (essentially, we tried to isolate a phage from our soil sample). From there, if we saw signs of plaque formation on an agar plate with our bacteria (M. smeg) after the enrichment process, we continued on with serial dilutions for purification, wherein we essentially purified our collected phage sample in order to try and ensure that we were specifically looking at one species of phage. As I explained in my presentation, our isolated phage that initially presented itself as temperate turned out to be lytic! This was really cool to us, considering we learned that lytic phages are the ones used in phage therapy, which is an alternative to antibiotic treatment in the medicine world!

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