13 thoughts on “C28 – Sanders

  1. My understanding is that the DNA damage is a natural process. However, I am curious as to what exactly is occurring when a double stranded breaks is present? Is it a spontaneous process or is it caused by a specific problem in the DNA?

    1. Hello, great question! DNA DSBs can occur in all organisms because of a variety of mostly environmental issues, including radiation, chemical agents, and replication stalling and are not caused by the DNA itself. When a DSB occurs, both DNA strands of a chromosome are cleaved in two, allowing them to physically move away from each other and preventing most methods of DNA repair.

  2. Is it known how tetrahymena is able to quickly break apart and re-splice together its genome?

    1. Hello! The exact process and reasoning behind the DSB creation and repair processes in T. therm are still unknown. According to this data, however, ubiquitin conjugating enzyme E2 (UbiconE2 protein) is likely involved in this process.

  3. How did you create double stranded breaks in the DNA? Would there be a difference in the expression of the primers in the PCR if there was only a double stranded break or is all DNA damage responded to the same?

    1. Hello! Hydroxyurea was used to create the DSBs by stalling the replication forks in the DNA. If single stranded breaks were introduced, gene expression would likely look the same as it does normally, as cells are able to repair single stranded breaks with minimal involvement using ligases. DSB repair is a comparatively very intense and risky process, and it is still not fully understood in all contexts.

  4. Really great and interesting presentation! Is it known what causes these double stranded breaks in the DNA in the first place?

    1. Hello! Many environmental factors, such as radiation and chemical agents, can initiate DSBs. The exact pathway that T. Therm uses is still unknown, however, in this experiment, hydroxyurea was used to stall the replication fork in T. therm and induce breakage in both strands of DNA.

  5. If there is an increase in expressivity of the DSB repairs, how are normally functioning cells impacted?

    1. Hello! As the DSB repair process is not yet fully understood in T. therm, it would be very difficult to say how excess DSB repair factors would affect an otherwise healthy cell. This would make for a very interesting experiment, however, which could lead to some really useful data!

  6. If there is an increase in expressivity of the DSB repairs, how are normally functioning cells impacted?

  7. Since DSB repairs have a important function for the ability of a cell to survive, do you think cancer cells be killed or prevented through the inhibition of DSB repairs?

    1. Very interesting comment! I feel that this could be a useful treatment, however, a lot of testing and dosage control would have to be done to ensure that healthy cells are able to repair their DNA. Some cancers can be caused by the misrepair of a DSB, so I think that using breakage to treat cancer cells (instead of trying to prevent the breakage in the first place) is a cool idea!

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