Abstract
Neuropeptides play essential roles in regulation of reproduction and growth in marine molluscs. But their function in marine bivalves – a group of animals of commercial importance – is largely unexplored due to the lack of systematic identification of these molecules. In this study, we sequenced and analyzed the transcriptome of nerve ganglia of Yesso scallop Patinopecten yessoensis, from which 63 neuropeptide genes were identified based on BLAST and de novo prediction approaches, and 31 were confirmed by proteomic analysis using the liquid chromatography-tandem mass spectrometry (LC-MS/MS). Fifty genes encode known neuropeptide precursors, of which 20 commonly exist in bilaterians and 30 are protostome specific. Three neuropeptides that have not yet been reported in bivalves were identified, including calcitonin/DH31, lymnokinin and pleurin. Characterization of glycoprotein hormones, insulin-like peptides, allatostatins, RFamides, and some reproduction, cardioactivity or feeding related neuropeptides reveals scallop neuropeptides have conserved molluscan neuropeptide domains, but some (e.g., GPB5, APGWamide and ELH) are characterized with bivalve-specific features. Thirteen potentially novel neuropeptides were identified, including 10 that may also exist in other protostomes, and 3 (GNamide, LRYamide, and Vamide) that may be scallop specific. In addition, we found neuropeptides potentially related to scallop shell growth and eye functioning. This study represents the first comprehensive identification of neuropeptides in scallop, and would contribute to a complete understanding on the roles of various neuropeptides in endocrine regulation in bivalve molluscs.
Highlights
Neuropeptides are intercellular signaling molecules secreted by neurons, acting as hormones, neurotransmitters, and modulators
The scallop ganglia transcriptome was assembled into 155,937 transcripts of 124,501 trinity “gene,” with an average length of 735 bp and N50 of 1,782 bp
The nerve ganglia transcriptome assembly serves as a reference database for the LC-MS/MS analysis and provides valuable resources for predicting neuropeptide genes using NpSearch
Summary
Neuropeptides are intercellular signaling molecules secreted by neurons, acting as hormones, neurotransmitters, and modulators. As modulators of neuronal activity, neuropeptides contribute to the generation of different outputs from the same neuronal circuit in a context dependent manner (Jékely, 2013), or organizing complex motor functions (Kim et al, 2006). They play key Neuropeptidome of Scallop Patinopecten yessoensis roles in regulating various physiological processes, including growth, metabolism, reproduction, etc. Insulin-like peptides can promote the growth of Drosophila (Slaidina et al, 2009), and regulate metabolism in Aplysia (Floyd et al, 1999). Feeding circuit-activating peptide is involved in the induction and maintenance of food-induced arousal (Sweedler et al, 2002). GnRH and kisspeptin participate in reproduction regulation in many vertebrates (Ottinger et al, 2002; Tsutsui et al, 2010; Gopurappilly et al, 2013)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
