Question

In an experiment you make two setups, in 1st you knock down the DAM and in 2nd you over express DAM. What will be the observation for both the setups?

(a) In 1st case BER is compromised and in 2nd MMR is compromised

(b) In 1st case MMR is compromised, while in 2nd MMR is more accurate

(c) In both cases MMR is compromised

(d) In both cased BER is compromised

I have been asked this question in unit test.

This interesting question is from Repair of DNA Damage: MMR, BER in section DNA Mutation, DNA Repair, Transposable Elements of Cytogenetics

Answer 1

Right choice is (c) In both cases MMR is compromised

The best explanation: DAM knockdown leads to no methylation, and then both strands are indistinguishable as both are not methylated. While in DAM over expression both are methylated at a shorter window giving lesser time for MMR to work. Thus, the MMR in either case is compromised.