Transposable elements and adaptive evolution in Drosophila

Josefa Gonzalez de l'Institut de Biologie Évolutive de Barcelone, invitée de l’équipe "Évolution, Vecteurs, Adaptation et Symbiose"

Transposable elements are likely to play a role in adaptive evolution because they are powerful mutagens that create a great variety of mutations. However, the role of transposable elements in adaptation has been understudied due to methodological limitations. Next-generation sequencing technologies allow us to study transposable-element-induced adaptations to an unprecedented scale.
We have performed a genome-wide screening looking for transposable element-induced adaptations in the model species Drosophila melanogaster. We have identified 41 insertions likely to play a role in adaptation to the out-of-Africa environments. 25 of these 41 putatively adaptive transposable elements show signatures of selection at the DNA level. Furthermore, we have been able to map four of these transposable element insertions to their ecologically relevant phenotypic effect and to unravel the molecular mechanism behind them. Our results suggest that transposable elements play an important role in stress-response pathways. Our results also showed the variety of molecular mechanisms by which transposable element affect gene regulation: from adding transcription factor binding sites to changing the 3’UTR lenght.

Josefa lab website: www.biologiaevolutiva.org/gonzalez_lab