Cnidarian-Dinoflagellate ‘Coup de Foudre’ : Deciphering the Mechanisms of Symbiosis Set-up – COUP-DE-FOUDRE

The cnidarian-dinoflagellate association represents one of the most important symbioses in the marine environment between a animal and a unicellular eukaryote (Symbiodiniaceae). This association is widespread in temperate and subtropical coastal ecosystems: it is the very foundation of the highly productive and diverse coral reef ecosystem.
This symbiosis is a mutualistic intracellular association, based on the photosynthetic activity of the endosymbiont. Inside the cytoplasm of some host gastrodermal cells, the endosymbiont triggers a complex communication with the host animal cells. Although this marine symbiosis has been investigated for several decades, the molecular signalling between the two partners and the symbiosis competency properties of the animal cell remain unresolved due to the absence of a model reliable for cellular and functional approaches.
Thus, the main objective of the ‘Coup de Foudre’ project is to decipher the specific molecular dialog underlying the symbiosis establishment and the possible influence of environmental changes by using in vitro cell cultures and pushing them to set-up in vitro co-culture system.
More precisely, we will address the following questions: i) Which host cells are symbiosis-competent? ii) is attractiveness shared by both partners of the symbiosis? iii) Which molecules and signalling pathways from animal host cells and/or symbiont cells are specifically involved? iv) Can environmental disturbances (linked to global change) alter the symbiosis establishment, by the impairment of molecular targets?
The proposed project takes advantage of the transdisciplinary expertise of the consortium on OMICs approaches and on recent advances on Cnidarian in vitro cell cultures.