title: Gonadotropin-releasing hormone and adipokinetic hormone/corazonin-related peptide in the female prawn.
abstract: Crustacean neuropeptides (NPs) play important roles in the regulation of most physiological activities, including growth, molting and reproduction. In this study, we have performed an in silico analysis of female prawn (Macrobrachium rosenbergii) neural transcriptomes to identify NPs not previously identified. We predict that approximately 1309 proteins are destined for the secretory pathway, many of which are likely post-translationally processed to generate active peptides. Within this neural secretome, we identified a gene transcript that encoded a precursor protein with striking similarity to a gonadotropin-releasing hormone (GnRH). We additionally identified another GnRH NP superfamily member, the adipokinetic hormone/corazonin-related peptide (ACP). M. rosenbergii GnRH and ACP were widespread throughout the nervous tissues, implicating them as potential neuromodulators. Furthermore, GnRH was found in non-neural tissues, including the stomach, gut, heart, testis and ovary, in the latter most prominently within secondary oocytes. The GnRH/corazonin receptor-like gene is specific to the ovary, whereas the receptor-like gene expression is more widespread. Administration of GnRH had no effect on ovarian development and maturation, nor any effect on total hemolymph lipid levels, while ACP administration decreased oocyte proliferation (at high dose) and stimulated a significant increase in total hemolymph lipids. In conclusion, our targeted analysis of the M. rosenbergii neural secretome has revealed the decapod GnRH and ACP genes. We propose that ACP in crustaceans plays a role in the lipid metabolism and the inhibition of oocyte proliferation, while the role of the GnRH remains to be clearly defined, possibly through experiments involving gene silencing.
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia.
authors.forename: Saowaros
authors.initials: S
authors.lastname: Suwansa-Ard
authors.affiliation: Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia.
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; School of Medicine, Walailak University, Nakhon Si Thammarat 80161, Thailand.
authors.forename: Tipsuda
authors.initials: T
authors.lastname: Thongbuakaew
authors.affiliation: Department of Anatomy, Phramongkutklao College of Medicine, Bangkok 10400, Thailand.
authors.forename: Piyachat
authors.initials: P
authors.lastname: Chansela
authors.affiliation: Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia.
authors.forename: Tomer
authors.initials: T
authors.lastname: Ventura
authors.affiliation: Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia. Electronic address: scummins@usc.edu.au.
authors.forename: Scott F
authors.initials: SF
authors.lastname: Cummins
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Faculty of Allied Health Sciences, Burapha University, Chonburi 20131, Thailand. Electronic address: prasert.sob@mahidol.ac.th.
authors.forename: Prasert
authors.initials: P
authors.lastname: Sobhon
mesh_terms: D000818:Animals; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007301:Insect Hormones / Q000378:metabolism*; D009479:Neuropeptides; D009842:Oligopeptides / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism; D033541:Palaemonidae / Q000378:metabolism*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D007301:Insect Hormones; D009479:Neuropeptides; D009842:Oligopeptides; C044833:adipokinetic hormone; D007987:Gonadotropin-Releasing Hormone; D011761:Pyrrolidonecarboxylic Acid
keywords: Adipokinetic hormone/corazonin-related peptide; Crustaceans; Gonadotropin-releasing hormone; Macrobrachium rosenbergii; Neuropeptide