Why do protein coding genes have a forward mutation at least an order of magnitude greater than the reverse?
Most protein coding genes have a forward mutation rate (normal to mutant) that is at least an order of magnitude greater than the reverse mutation rate (Mutant back to normal). Why should this be the case?
- Anonymous8 years agoFavorite Answer
Quite simply, any change to the normal gene causes a mutant.
But to go from mutant back to normal, it takes a very specific reverse mutation.
Take, for instance, the following DNA sequence: AAAA
Any of the following "forward mutations" gives rise to a mutant: AATA, AACA, AAAG, GAAA, ATAA, etc...
But to go from one specific mutant (e.g. AATA) back to AAAA, the T MUST revert back to a A.