Epigenetic effects of transposable elements along linear chromosomes
Organisms have evolved ways to “mark” TE sequences with repressive epigenetic marks, which reduce the ability of TEs to move and to multiply. However, these repressive epigenetic marks at TEs inadvertently “spread” to neighboring genes along the linear chromosome. We found that this phenomenon (“epigenetic effects of TEs”) is prevalent across Drosophila genomes (as well as in other animal and plant species!), interferes with gene function, and impairs hosts’ fitness. In other words, TEs are deleterious because of host silencing mechanisms evolved to reduce TEs’ harmful effects. We are investigating why organisms failed to curb these harmful side effects and studying the associated functional consequences on the evolution of both host genomes and TEs.