Our group focuses on the genetic origin of trait diversification. For many animal groups, closely related species are distinguished by subtle variations in their morphology or their behavior. Some sort of variation on a theme. The theme can be colors, simple forms, textures, fancy choreographies during courtship, or other stereotypic reproductive behaviors. These variations are shaped over evolutionary times through the interplay of two forces, arising genetic variation and natural selection. We concentrate on the genetic origin of this variation. We want to understand how changes in the DNA sequence translate at the levels of gene function, gene expression, biology of cells, and ultimately into a new phenotype.

We use fruit fly species (Drosophila ssp.) that differ in their morphologies and their behaviors in defined and heritable ways, and seek to unravel the genetic underpinnings of these differences. This currently results in two large projects in the lab.

One project analyzes color patterns on fly wings. The evolutionary gain of such wing paintings, as well as their subsequent diversification, result at large from changes in the transcription of genes controlling pigment formation. Therefore, a large part of our work focuses on the control of transcriptional regulation, rewiring of a gene regulatory network, and the qualitative and quantitative outputs produced by these changes.

The other project studies how an innate reproductive behavior has diversified among Drosophila species. While many Drosophila species associated to humans are laying their eggs in decaying fruits, one of them, Drosophila suzukii, has gained the ability to target earlier stages of fruit maturation. In less than a decade, Drosophila suzukii, has become an agricultural pest for the Western world, by the damages it causes to the cultures of our favorite fruits (strawberries, raspberries, grapes,…). To understand the evolution of this behavior, we are comparing the genetic and neuronal determinants of egg-laying behavior between D. suzukii and other species that target decaying fruit for egg-laying.

In general, our work combines genetics, genomics, and quantitative phenotype analysis, always in a comparative evolutionary framework. We select species representing an ancestral situation and compare them to species representing a derived situation.