title: The effects of serotonin, dopamine, gonadotropin-releasing hormones, and corazonin, on the androgenic gland of the giant freshwater prawn, Macrobrachium rosenbergii.
abstract: Neurotransmitters and neurohormones are agents that control gonad maturation in decapod crustaceans. Of these, serotonin (5-HT) and dopamine (DA) are neurotransmitters with known antagonist roles in female reproduction, whilst gonadotropin-releasing hormones (GnRHs) and corazonin (Crz) are neurohormones that exercise both positive and negative controls in some invertebrates. However, the effects of these agents on the androgenic gland (AG), which controls testicular maturation and male sex development in decapods, via insulin-like androgenic gland hormone (IAG), are unknown. Therefore, we set out to assay the effects of 5-HT, DA, l-GnRH-III, oct-GnRH and Crz, on the AG of small male Macrobrachium rosenbergii (Mr), using histological studies, a BrdU proliferative cell assay, immunofluorescence of Mr-IAG, and ELISA of Mr-IAG. The results showed stimulatory effects by 5-HT and l-GnRH-III through significant increases in AG size, proliferation of AG cells, and Mr-IAG production (P<0.05). In contrast, DA and Crz caused inhibitory effects on the AG through significant decreases in AG size, proliferation of AG cells, and Mr-IAG production (P<0.05). Moreover, the prawns treated with Crz died before day 16 of the experimental period. We propose that 5-HT and certain GnRHs can be now used to stimulate reproduction in male M. rosenbergii, as they induce increases in AG and testicular size, IAG production, and spermatogenesis. The mechanisms by which these occur are part of our on-going research.
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Tanapan
authors.initials: T
authors.lastname: Siangcham
authors.forename: Yotsawan
authors.initials: Y
authors.lastname: Tinikul
authors.forename: Jaruwan
authors.initials: J
authors.lastname: Poljaroen
authors.forename: Morakot
authors.initials: M
authors.lastname: Sroyraya
authors.forename: Narin
authors.initials: N
authors.lastname: Changklungmoa
authors.forename: Ittipon
authors.initials: I
authors.lastname: Phoungpetchara
authors.forename: Wilairat
authors.initials: W
authors.lastname: Kankuan
authors.forename: Chanudporn
authors.initials: C
authors.lastname: Sumpownon
authors.forename: Chaitip
authors.initials: C
authors.lastname: Wanichanon
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hanna
authors.forename: Prasert
authors.initials: P
authors.lastname: Sobhon
mesh_terms: D000728:Androgens / Q000378:metabolism; D000818:Animals; D004298:Dopamine / Q000494:pharmacology*; D004702:Endocrine Glands / Q000187:drug effects* / Q000378:metabolism*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D019476:Insect Proteins / Q000494:pharmacology*; D008297:Male; D009479:Neuropeptides / Q000494:pharmacology*; D033541:Palaemonidae / Q000187:drug effects* / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology*
chemical_list: D000728:Androgens; D019476:Insect Proteins; D009479:Neuropeptides; C060602:corazonin protein, insect; D012701:Serotonin; D007987:Gonadotropin-Releasing Hormone; D004298:Dopamine
keywords: Androgenic gland; Dopamine; Gonadotropin-releasing hormone; Insulin-like androgenic gland hormone; Macrobrachium rosenbergii; Serotonin