Are there any mutagens that can undo the mutations they cause?

Question

I was reading a section from my textbook about tautomeric shifts, and it seems to suggest that there are some mutagens that can be directly responsible for the phenomenon. The section is mainly describing spontaneous mutations as opposed to induced mutations, and examples of mutagens are mentioned. However, the author explicitly states that the sort of changes made to DNA due to spontaneous mutations also occur at a higher rate during induced mutagenesis.If a tautomeric shift can occur due to mutagenic activity, is it possible for the mutagen to undo and "correct" the mutation by reversing the shift? If so, what kind of chemicals or physical mutagens (e.g. radiation) would be involved?

Answer 1

It is possible for a mutation to mutate back to its original DNA sequence, during cell division. Research is needed as to how often this happens in real life. Mutation hotspots are locations within a gene where mutations tend to be found more often. It seems reasonable to take a guess that a back-mutation is more likely to happen at a mutation hotspot. Again, research is needed.