Identification and structural and functional characterization of neuropeptides in 4 coral species.

Hard corals, or Scleractinians, are key organisms in reef ecosystems, which serve as true reservoirs of marine biodiversity. Beyond their major ecological role, these animals are of considerable economic importance in tropical and subtropical zones, where they support fishing, tourism, and provide protection for coastal areas against erosion by acting as natural breakwaters.

However, these fragile ecosystems are experiencing accelerated global decline, due to the combined effects of coastal anthropization, climate warming, the spread of pathogens, and contamination by microplastics or certain chemical compounds found in sunscreens. Since 2009, approximately 14% of coral reefs have disappeared, highlighting the urgent need for their preservation.

Understanding coral physiology is an essential prerequisite for predicting environmental impacts, as well as for developing effective strategies for culture and reef restoration. However, current knowledge remains limited, particularly concerning the role of neuropeptides in regulating the physiological functions of these organisms.

Cnidarians, the group to which corals belong, do not possess a central nervous system, but a diffuse nerve net allowing them to perceive environmental stimuli, regulate their physiological functions, and fight against pathogens. In some cnidarians, such as hydras or jellyfish, neuropeptides, derived from precursors called preprohormones, act as modulators or hormones involved in various physiological functions, including polyp contraction, larval metamorphosis, colonization, gamete maturation, and immune response. More than fifty neuropeptides have been identified in cnidarians, but only two groups have been described and characterized in corals to date.

My research work is part of a Franco-Taiwanese ANR project (Coral Neuropeptide Project – CNP), aiming to identify and structurally and functionally characterize the neuropeptides present in 4 coral species: Fimbriaphyllia ancora, Stylophora pistillata, Acropora tenuis, and Galaxea sp. The methodological approach combines genomic analyses, based on the in silico annotation of genomes, transcriptomic studies to evaluate gene expression under different environmental conditions, and a peptidomic approach using mass spectrometry, intended to identify and quantify all the peptides and neuropeptides produced in these 4 species.