Microbes, hosts, environment

I dedicate much of my research to the study of symbiosis in animals and the link with environmental conditions they experience, especially when they are toxic, extreme, and variable.

I try to understand how interactions and symbioses between microorganisms and their hosts contribute to the adaptation of organisms to life in extreme or stressful environments.

Indeed, microbiota is most often located at the interface between host and environment. It reacts to and interacts with stress and contaminants, and affects hosts.

My research sits at the interface between microbial ecology (identification of microbial partners, their capabilities and fuctioning...), animal biology (tissue alterations, transmission modes, life cycles, nutrition...), and ecotoxicology (impact of toxic compounds).

This way of accounting for the microbiome in ecotoxicology studies is nicknamed "Microbiome-aware ecotoxicology"

Microbiome-aware ecotoxicology applied to fish

I recently started a line of research that aims at undertsading how fish-associated microbiota react to environmental stressors including exposure to the cyanobacterial blooms that occur with increasing frequency and intensity in freshwater lentic ecosystems worldwide.

For this, we conduct field work to address microbiome composition in wild fish,and we conduct experimental work in microcosms on the medaka fish (Oryzias latipes), a common and convenient model for ecotoxicology studies. This small fish resists many types of stress and is easy to rear in the laboratory. We can expose fish to various controlled conditions in microcosms setups (for example, to toxins or simulated blooms), and then study how their microbiota composition and functions change. With this, we can test how environmental stressors affect fish physiology and associated microbiota.

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Marine chemosynthetic symbioses and deep-sea biology

Among the most original symbiotic association that help hosts thrive in extreme and toxic environments are those involving marine invertebrates and bacteria which perform primary production in the absence of light by oxidizing reduced chemical compounds (chemoautotrophy). These symbioses are responsible for the high biomasses observed around extreme environments such as deep-sea hydrothermal vents and cold seeps. These symbioses, their functioning, evolution and significance for biogeochemical cycles remain barely understood.

One of my research topics aims at discovering, describing and understanding the role of chemosynthetic symbioses in various mostly invertebrate groups including bivalves (mytilids, lucinids, thyasirids, vesicomyids...), gastropods, annelid tubeworms (vestimentiferans). I also participate to the characterization of novel types of associations in groups that are not yet studied, including xylophagous bivalves, mangrove crabs, and deep-sea corals.