Evolution of decision-making neuronal circuits in the pest Drosophila suzukii

Description

A central question in neurobiology is to understand at the genetic, molecular and cellular levels how neuronal circuits generate behaviors. Higher brain functions such as multi-sensory integration and decision-making processes are particularly poorly understood. In addition, how these functions are modified during evolution to promote the appearance of novel behaviors remains largely unknown.
The PhD project will address these questions by investigating the neuronal mechanisms underlying the evolution of an innate behavior in Drosophila species.
More specifically, we study how fruit fly females decide where to lay their eggs. The pest species Drosophila suzukii has evolved a divergent preference for laying its eggs on ripe fruits compared to other species such as the model D. melanogaster which prefer laying on fermented/rotten fruits. D. suzukii is an invasive species spreading across the world and its novel egg-laying behavior causes substantial losses to the fruit industry.
Using a combination of behavioral assays and genetic tools, we have demonstrated that D. suzukii’s behavioral divergence is linked to differences in how it processes sensory information in its Central Nervous Systems (CNS) compared to D. melanogaster. In particular, D. suzukii appears to give more weight to information about the sugar content of egg-laying substrates.
The proposed project will compare the physiological properties and functional role of homologous neuronal circuits controlling egg-laying decisions in the two species in response to these sensory inputs. We aim to identify the neurons which function differently in the two species and cause the divergence of behavior. This will involve generating new transgenic lines, performing anatomical comparisons of neuronal circuits (microscopy), behavioral assays, and functional imaging studies (calcium imaging) to monitor and compare the activity of these circuits across species.

Nature de finanement

A*Midex ou Labex

Profil recherché

The candidate should be highly motivated and with a strong interest in fundamental research, more specifically in neurobiology, behavior, genetics and developmental biology. A solid background in neurobiology, microscopy and quantitative analyses is expected. Expertise in dissection, Drosophila genetics and behavioral studies will be an asset.

Employeur

The IBDM is an internationally-renowned research center affiliated with CNRS and Aix-Marseille University. The institute is composed of 21 research team exploring a diverse range of topics in cell/developmental biology and neuroscience. The institute is located on the Marseille Luminy Campus in the heart of the Calanques National Park.

The research team is led by Benjamin Prud’homme (DR1 CNRS) and is composed of researchers, engineers and students. The team uses multidisciplinary approaches to study evolution of behavior and gene regulation in Drosophila species. The evolution of behavior project is led by Matthieu Cavey (Associate professor), who has extensive experience in Drosophila neurobiology and behavior.