Julie Reveillaud

(Meta)genomic and transcriptomic analyses of the hydrothermal shrimp Rimicaris exoxulata symbionts

PostDoctoral Fellow:Dr Julie Reveillaud
Scientific Sponsors and Co-worker:

Dr Marie-Anne Cambon-Bonavita and Valérie Cueff-Gauchard,
Laboratory of Microbiology of Extreme Environments,
LM2E, UMR 6197,
Département Ressources physiques et écosystèmes de fond de mer,
Unité Etudes des Ecosystèmes Profonds,
Ifremer Brest BP 70 29280 Plouzané, France

LabexMER Research Axis 3: Geobiological interactions in extreme environments.

Life within deep hydrothermal vents is based on chemosynthetic primary production and animal-microbe associations are widespread. The charismatic shrimp Rimicaris exoculata dominates the fauna of hydrothermal sites along the Mid Atlantic ridge. The species harbors a complex bacterial community including Epsilon-, Gamma- and some recently discovered Zetaproteobacteria within its gill chamber as well as long microbial filaments within the digestive tract. In vivo experiments provide evidence of direct nutritional transfers from bacteria to the host across the gill chamber -therefore a true mutualistic association - and in silico analyses suggest three metabolic types (iron, sulfide and methane oxidation) may co-occur within this community.

Our current research project build on these previous studies and aims at using state-of-the-art metagenomic and metatranscriptomic methods to reconstruct genomes of the different symbiotic lineages, unravel their metabolic potential as well as their expression in varying –high-pressure- experimental conditions. We expect the study of ecologically vital, energy-harvesting microbes will provide new and important insights into the fundamental ecological and evolutionary mechanisms underlying intimate host-microbes associations.

Figure 1 : Rimicaris exoculata individuals covering active chimneys in the Mid-Atlantic Rainbow Ridge.

Figure 2 : FISH (Fluorescence in Situ Hybridization) images of gill chambers from different shrimp individuals with epibionts. Gammaproteobacteria (red), Epsilonproteobacteria (green) (a) and methanotrophic Gamma symbionts (orange) (c).