TE-dynamics in population divergence

​​Population divergence involves the accumulation of genetic differences across the genome. Such divergence is often driven by ecological adaptation. However, endogenous genetic barriers as a result of intrinsic genetic incompatibilities can also impede neutral gene flow and thus substantially contribute to population differentiation. As transposable elements (TEs) evolve rapidly, transpose throughout the genome and may lead to chromosomal rearrangements by ectopic recombination, it is reasonable to consider them as a common driver of genomic diversification among conspecific populations, eventually leading to speciation.

• We investigated differential TE abundance among conspecific populations of the nonbiting midge Chironomus riparius and evaluated their potential role in causing endogenous genetic incompatibilities between these populations. We focussed on a Chironomus-specific TE, the minisatellite-like Cla-element, whose activity is associated with speciation in the genus. This first part of our TE-research is published in Oppold et al. 2017, Molecular Ecology.
• The idea that TEs can cause reproductive isolation (RI) and are thus involved in the formation of species has attracted attention of speciation geneticists ever since TEs have been discovered by Barbara McClintock in 1950. Yet, we do not understand if TEs actually initiate the process of speciation; how they build barriers of RI and by which molecular mechanisms such barriers can be maintained. To answer these questions, we will soon start off a new and exciting long-term evolution experiments with Chironomus riparius.