The nobel prize winner Barbara McClintock suggested twenty years ago that maize under certain stress conditions could “reshape” its genome due to the effect of certain mobile elements. These mobile elements , a.k.a transposons, would literally jump from its location and insert somewhere else within the genome, therefore dramatically altering the original structure.
What makes them really interesting to me is the fact that they are “orchestrated”. What do I mean with this? well, I previously thought that the presence/absence and transposition of these elements was fairly independent from the genome where they were “integrated”. I kind of saw them as foreign DNA which entered the genome and had an unknown function. Obviously, I was puzzled because I think that calling a certain region with unknown function “junk” DNA is sometimes a quick way to avoid dealing with our lack of knowledge ( for further disagreement see this post in evolgen). Then I read that under stress conditions we have this jumping machinery that can, when excising and inserting in different positions, originate mutations therefore generating some sort of variation.
Also transposons are found to be inactivated by methylation, so the genome controls their activity (excision). Only in part? I don’t know.
So does the “host” genome controls these genes? Do they “belong” to the genome and are some sort of mutation tool to use when things go really wrong like SOS repair system?
I would like to know more!!