Evolution and development of morphology and behavior
Group leader : B. Prud’homme
Our group studies the genetic mechanisms that give rise to new characters and those that allow these characters to diversify between species.
The diversity of forms and behaviors that we witness in animals around us results from evolutionary changes. Evolution is a two-step process: First, the information contained in DNA sequences that determine animals’ traits, for instance their shapes and behaviors, changes over time by accumulating random mutations. These mutations may determine new traits or variations on existing traits. In a second step, these variations are sorted out by natural selection. The selective process will endow some individuals harboring a particular set of mutations with a higher chance of survival and a larger progeny, compared to others individuals equipped with different mutations, which will be progressively eliminated over time.
Our team is interested in the evolutionary process as a whole, with a strong emphasis on the first aspect, how novelty arises and diversifies. We are studying these questions in fruitfly species (Drosophila), along two main lines of research. Namely, we use pigmentation patterns on fly wings as a model system to study the evolution of morphology, and in parallel, we also study how different reproductive behaviors evolved in these flies. Beyond identifying how genes have changed to produce novel traits, our goal is to address how these two categories of traits –forms and behaviors– often evolve in concert.
We are interested in understanding the genetic and developmental bases of phenotypic novelty. We are addressing this question mostly by studying as a model system the evolution of a male specific wing pigmentation patterns present in some Drosophila species, in particular Drosophila biarmipes and its closely related species. The males of these species have also evolved along with wing pigment patterns a specific wing display courtship behavior. Our previous work has revealed that functional modifications of cis-regulatory sequences of pigmentation genes, mainly by co-option of existing regulatory information, played a major role in the diversification of pigmentation patterns. We are expanding this work along two lines of research:
1) we want to reconstruct the gene regulatory network involved in the formation and the evolution of wing pigment patterns and characterize the genetic modifications in this network underlying phenotypic variation within and between species. We rely on various approaches including genetics, comparative genomics, bioinformatics, biochemistry and in vivo transgenic functional assays to achieve this goal.
2) we are testing whether sexual selection is involved in the evolution of this wing pigment pattern and the associated courtship behavior . Also, we want to assess the role of extant natural variation as the raw material for these novelties. Large sampling of natural populations as well as female choice preference tests using wild caught or genetically modified flies will allow testing and evaluating the selective forces involved.
In addition, we are exploring the neuronal and genetic bases underlying the assembly and the evolution of a novel behavior. Specifically, we are studying how Drosophila suzukii, another wing spotted species, has changed its oviposition site preference from rotting fruits (common to most Drosophila species) to fresh, ripening fruits. This species, which is in the process of invading the world, represents a serious threat to fruits growers because of this behavioral shift. In order to better understand how this species has changed its ecological niche we are using an interspecies comparative approach to dissect the contribution of specific genes and neural circuits on the control of oviposition behavior.
March 8th, 2017
Evolution of Multiple Sensory Systems Drives Novel Egg-Laying Behavior in the Fruit Pest Drosophila suzukii
March 22nd, 2013
Emergence and diversification of fly pigmentation through evolution of a gene regulatory module.
January 1st, 2012
Evolution of multiple additive loci caused divergence between Drosophila yakuba and D. santomea in wing rowing during male courtship.
June 5th, 2011
Body plan innovation in treehoppers through the evolution of an extra wing-like appendage.
May 15th, 2007
Emerging principles of regulatory evolution.
July 1st, 2006
Monkey see, monkey do.
April 20th, 2006
Repeated morphological evolution through cis-regulatory changes in a pleiotropic gene.
February 3rd, 2005
Chance caught on the wing: cis-regulatory evolution and the origin of pigment patterns in Drosophila.
February 23rd, 2013
Smells like evolution: the role of chemoreceptor evolution in behavioral change.
March 6th, 2012
Evolution: return of the ant supersoldiers.
October 12th, 2011
Behavioural neuroscience: Fruity aphrodisiacs.
December 9th, 2010
Evolutionary biology: Genomic hourglass.
October 15th, 2009
Behavioural neurobiology: Chemical love.
August 1st, 2009
The causes of repeated genetic evolution.
May 1st, 2008