Transcriptome Profiling of the Pacific Oyster Crassostrea gigas Visceral Ganglia over a Reproduction Cycle Identifies Novel Regulatory Peptides

• Published in: Marine Drugs
• Main Authors: Emilie Réalis-Doyelle, Julie Schwartz, Cédric Cabau, Lorane Le Franc, Benoit Bernay, Guillaume Rivière, Christophe Klopp, Pascal Favrel
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2021
• Subjects: nervous system; transcriptome; neuropeptides; reproduction; Biology (General); QH301-705.5; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://doi.org/10.3390/md19080452; https://doaj.org/article/a541bd386a744488bf7b49532911d21b

The neuropeptides involved in the regulation of reproduction in the Pacific oyster ( Crassostrea gigas ) are quite diverse. To investigate this diversity, a transcriptomic survey of the visceral ganglia (VG) was carried out over an annual reproductive cycle. RNA-seq data from 26 samples corresponding to VG at different stages of reproduction were de novo assembled to generate a specific reference transcriptome of the oyster nervous system and used to identify differentially expressed transcripts. Transcriptome mining led to the identification of novel neuropeptide precursors (NPPs) related to the bilaterian Eclosion Hormone (EH), crustacean female sex hormone/Interleukin 17, Nesfatin, neuroparsin/IGFBP, prokineticins, and urotensin I; to the protostome GNQQN, pleurin, prohormones 3 and 4, prothoracotropic hormones (PTTH), and QSamide/PXXXamide; to the lophotrochozoan CCWamide, CLCCY, HFAamide, and LXRX; and to the mollusk-specific NPPs CCCGS, clionin, FYFY, GNamide, GRWRN, GSWN, GWE, IWMPxxGYxx, LXRYamide, RTLFamide, SLRFamide, and WGAGamide. Among the complete repertoire of NPPs, no sex-biased expression was observed. However, 25 NPPs displayed reproduction stage-specific expression, supporting their involvement in the control of gametogenesis or associated metabolisms.