Isabelle DOMART-COULON

Invited Professor of EPFL ENAC (switzerland) since 2013

Research Activities : Interactions between microorganisms and their host

1) Coral microbiology : taxonomic and functional diversity of scleractinian coral algal symbionts during host life cycle (from planula larva to adult colony polyp)  2 types of microalgal partners are studied, ie., Symbiodiniaceae (photosynthetic dinoflagellates) endosymbionts of coral tissue, and Ostreobiaceae (carbonate microboring Bryopsidale algae) ectosymbionts of coral skeletons.

 Biogeochemistry of trophic exchanges between microalgae and coral host are investigated via stable isotope tracer’s incorporation into photosynthetic and N-cycle metabolites. Pulse-chase labeling experiments with 13C-bicarbonate, 15N-nitrate are followed by EA-IRMS or NanoSIMS quantification of tissue isotopic enrichment – respectively in bulk (at biomass level) or spatially resolved (at subcellular compartment level). Studies are performed either in vitro, using laboratory-isolated and propagated model strains of Ostreobiaceae and aquarium-emitted and laboratory-reared Pocillopora acuta coral larvae, or in hospite in adult coral colony fragments colonized with natural microalgal (Symbiodiniaceae, Ostreobiaceae) assemblages. (Kopp et al 2016, Massé 2018 PhD)

Developmental biology of coral-algal symbiosis : host colonization dynamics by Symbiodiniaceae or Ostreobiaceae are investigated in coral early life stages (planula larva metamorphosis into polyp), and in adult colony (polyp clonal budding). Combined use of molecular (taxonomic marker sequencing/barcoding) and microscopy (fluorescence / electron microscopy imaging) methods. (Lecointe et al 2016, Massé et al 2018)

Characterization of the microbiota of Ostreobiaceae algae : taxonomic composition and FISH visualization of their associated bacterial communities and sensitivity to abiotic, salinity stress (Massé et al, 2023 in revision)

 Ecophysiology of coral–isolated Ostreobiaceae strains : differential carbon and nitrogen assimilation patterns and pigment and lipid variation across habitats (free-living vs bioeroding growth forms) (Massé et al. 2020); fatty acids and photobiological response to salinity stress (MS in prep).

2) Molecular signaling of cnidarian larval settlement, induced by biofilms or neurotransmitters

Characterization of biomolecules (metabolites and peptides) that regulate coral early life stage transitions, with a focus on larval metamorphosis into polyp (ANR project ‘MOPSEA’ 2022-2026 & Sorbonne-Université EMERGENCE ‘CLASSE’ 2021-2023)  (Nicault et al, in prep)

3) Systematic reviews and meta-analyses  of cellular models for marine invertebrate  microbiology and biology studies, and of chemical pollution impacts on reef corals

Meta-analysis of marine invertebrate cell culture methods (WP1 of european COST1603 Maristem) (Domart-Coulon & Blanchoud 2022 MDPI book chapter https://doi.org/10.3390/books978-3-0365-1635-6-1 and curated database of bibliography references)

Contribution to a systematic review and the establishment of knowledge map of the evidence on the impacts of chemicals arising from human activity on tropical reef-building corals (Ouédraogo et al. 2021 https://doi.org/10.1186/s13750-021-00237-9). Contribution to  systematic review on the  the toxicity thresholds of chemicals for tropical reef-building corals (Ouédraogo et al. 2023 https://doi.org/10.1186/s13750-023-00298-y)

Science Outreach

2 art & sciences projects : (2018-2019) "Corail Artefact" with artist Jeremy Gobé ; (2020-2022) "Corallum Fabrica" with designer Elise Rigot (PhD)