Interference between viruses and transposons in Drosophila.

Transposable elements (or transposons) are DNA sequences, which present themselves as parasites of the genomes. They are able to move and multiply along chromosomes. They are present in all organisms and make up half of the human genome. When they transpose, they cause mutations, which can be deleterious, but also a source of genetic innovation. The activity of transposable elements is not constant over time. And while it is known that certain factors such as stress can trigger transposition, the understanding of the dynamics of these sequences within genomes is still only partial.

The study developed by a research team within the Biometrics and Evolutionary Biology Laboratory and the Viral Infections and Comparative Pathology Laboratory, financially supported by the LabEx Ecofect within the framework of the ERMIT project, has shown that viral infections are a new factor at the origin of the modulation of the activity of transposable elements. Indeed, by using different lines of fruit flies infected by the Sindbis arbovirus, it appears that the quantity of transcripts of transposable elements, which are essential for transposition, varies upon viral infection. These modulations involve RNA interference pathways, which are involved in the antiviral response of drosophilia.

Considering that viral infections impact transposable element activity, these results suggest that they may play a role in modulating the speed of genome evolution.
 

Reference article 

Roy, M., Viginier, B., Saint-Michel, É., Arnaud, F., Ratinier, M., & Fablet, M. (2020). Viral infection impacts transposable element transcript amounts in Drosophila. Proceedings of the National Academy of Sciences, 117(22), 12249-12257.
doi : https://doi.org/10.1073/pnas.2006106117

* Biometrics and Evolutionary Biology Laboratory (LBBE - Unviersité Claude Bernard Lyon 1 / CNRS / VetAgro Sup)

* Viral Infections and Comparative Pathology Laboratory (IVPC - Université Claude Bernard Lyon 1 / EPHE / INRAE)

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