Coloration patterns are among the most conspicuous traits that distinguish closely related species or individuals of opposite sexes in a species. These morphological patterns are also excellent read-outs of gene expression patterns and their variation. Studying the evolution of coloration patterns among closely related Drosophila species or natural color morphs of the ladybird Harmonia axyridis, therefore, lead us to study the evolution of transcriptional regulation.
Males and females from the same species share almost the same genome, yet they can be phenotypically quite distinct.
We study the mechanisms underlying the sex-biased expression of the Drosophila X-linked gene yellow, which we have recently shown, is controlled by an interallelic interaction. This interaction can only occur in XX females, but not in XY males.
D. suzukii, an invasive species that invaded Europe and North America about a decade ago, is an agricultural pest species that lay eggs in ripe fruit, including many red berries and soft-skinned fruits. This egg-laying behavior contrasts with most other Drosophila species, in particular D. melanogaster, that target overripe or fermenting fruit. We are studying how D. suzukii find and choose their preferred egg-laying substrates, and which genetic and neural changes accompanied the behavioral evolution of this species.
In addition to its novel egg-laying behavior, D. suzukii has evolved an elongated egg-laying organ, or ovipositor. This, presumably, helps to pierce the skin of ripe fruit. We are studying the morphogenesis of the ovipositor in Drosophila and its evolution in D. suzukii, at the cellular and tissue levels.