This week a paper published in current biology describes how developing embryos of Drosophyla keep their transposons shut by using “rasiRNA” pathways. Mutations of these genes lead to an increase in transposition of mobile elements with the consequent havoc it produces in the stability of the chromosomes.

Interestingly once the transposons started jumping a protein called Chk2 kicked in preventing cell division.
So you don’t have to worry your transposons are under control. This paradoxical entities novelty-makers-genomic-wreckers.