Structural and functional characterization of an egg-laying hormone signaling system in a lophotrochozoan – The pacific oyster (Crassostrea gigas)

• Published in: General and Comparative Endocrinology
• Main Authors: Favrel, Pascal, Dubos, M.P., Bernay, B., Pasquier, J., Schwartz, J., Lefranc, B., Mouret, L., Rivière, G., Leprince, J., Bondon, A.
• Other Authors: Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Interactions Cellules Organismes Environnement (ICORE), Normandie Université (NU)-Normandie Université (NU)-CHU Caen, Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN)-Tumorothèque de Caen Basse-Normandie (TCBN), Neuroendocrine, Endocrine and Germinal Differentiation Communication (NorDic), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS), Plate-Forme de Recherche en Imagerie Cellulaire de Haute-Normandie (PRIMACEN), Normandie Université (NU)-Normandie Université (NU)-Institute for Research and Innovation in Biomedicine (IRIB), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-High-tech Research Infrastructures for Life Sciences (HeRacLeS), Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS), Council of the Normandy Region (RIN ECUME: 18E01643-18P02383
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: Oyster; GPCR; Egg-laying hormone; Reproduction; Stress; [SDV]Life Sciences [q-bio]; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://hal.science/hal-04317342; https://hal.science/hal-04317342/document; https://hal.science/hal-04317342/file/GCE-D-23-00260_R1-UM.pdf; https://doi.org/10.1016/j.ygcen.2023.114417

International audience The egg-laying hormones (ELHs) of gastropod mollusks were characterized more than forty years ago. Yet, theyhave remained little explored in other mollusks. To gain insights into the functionality of the ELH signalingsystem in a bivalve mollusk – the oyster Crassostrea gigas, this study investigates the processing of its ELH pre-cursor (Cragi-ELH) by mass spectrometry. Some of the ELH mature peptides identified in this study were sub-sequently investigated by nuclear magnetic resonance and shown to adopt an extended alpha-helix structure in amicellar medium mimicking the plasma membrane. To further characterize the ELH signaling system in C. gigas,a G protein-coupled receptor phylogenetically related to ecdysozoan diuretic hormone DH44 and corticotropin-releasing hormone (CRH) receptors named Cragi-ELHR was also characterized functionally and shown to bespecifically activated by the two predicted mature ELH peptides and their N-terminal fragments. Both Cragi-ELHand Cragi-ELHR encoding genes were mostly expressed in the visceral ganglia (VG). Cragi-ELH expression wassignificantly increased in the VG of both fully mature male and female oysters at the spawning stage. When theoysters were submitted to a nutritional or hyposaline stress, no change in the expression of the ligand or receptorgenes was recorded, except for Cragi-ELHR only during a mild acclimation episode to brackish water. Theseresults suggest a role of Cragi-ELH signaling in the regulation of reproduction but not in mediating the stressresponse in our experimental conditions.