title: Presence of gonadotropin-releasing hormone-like peptide in the central nervous system and reproductive organs of the male blue swimming crab, Portunus pelagicus, and its effect on spermatogenesis.
abstract: Our previous studies have demonstrated that lamprey gonadotropin-releasing hormone-III (lGnRH-III)-like peptide occurs in the central nervous system (CNS) of decapod crustaceans (Macrobrachium rosenbergii, Penaeus monodon, Portunus pelagicus), and that lGnRH-III is the most potent in stimulating ovarian maturation compared with other GnRH isoforms. In this study, we examined the localization of lGnRH-III-like peptide in the CNS and male reproductive organs of the blue swimming crab by using anti-lGnRH-III as a probe. In the brain, lGnRH-III immunoreactivity (-ir) was detected in neurons of clusters 6, 10, 11, 14/15, 16, and 17 and in many neuropils. In the subesophageal ganglion, lGnRH-III-ir was present in neurons of the dorso-lateral and ventro-medial clusters. In the thoracic ganglia, lGnRH-III-ir was observed in the large-sized neurons between the thoracic neuropils and in the ventromedial cluster of the abdominal ganglia. In the testis, lGnRH-III-ir was detected in nurse cells, hemocytes, spermatids 2, and the outer and inner zones of the acrosomes of spermatozoa. Bioassay showed that lGnRH-III significantly increased the testis-somatic index, the percentage of late stages of seminiferous tubules (stages VII-IX), the diameter of the seminiferous tubules, and the number of BrdU-labeled early germ cells compared with the control groups. Thus, lGnRH-III-like peptide exists in the male crab and possibly enhances germ cell proliferation and maturation in the testes, leading to increased sperm production.
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok, 10400, Thailand.
authors.forename: Thanyaporn
authors.initials: T
authors.lastname: Senarai
authors.affiliation: Department of Anatomy, Faculty of Science, Prince of Songkla University, Songkhla, 90110, Thailand.
authors.forename: Jirawat
authors.initials: J
authors.lastname: Saetan
authors.affiliation: Coastal Aquatic Feed Research Institute, Coastal Fisheries Research and Development Bureau, Department of Fisheries, Petchaburi, 76130, Thailand.
authors.forename: Montakan
authors.initials: M
authors.lastname: Tamtin
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok, 10400, Thailand.
authors.forename: Wattana
authors.initials: W
authors.lastname: Weerachatyanukul
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok, 10400, Thailand.|Faculty of Allied Health Sciences, Burapha University, Chonburi, 20131, Thailand.
authors.forename: Prasert
authors.initials: P
authors.lastname: Sobhon
authors.affiliation: Department of Anatomy, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok, 10400, Thailand. prapee.sre@mahidol.ac.th.
authors.forename: Prepee
authors.initials: P
authors.lastname: Sretarugsa
mesh_terms: D000818:Animals; D003386:Brachyura / Q000378:metabolism*; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002490:Central Nervous System / Q000166:cytology / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D008297:Male; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D012098:Reproduction; D012671:Seminiferous Tubules / Q000166:cytology / Q000378:metabolism; D013091:Spermatogenesis; D013550:Swimming; D013737:Testis / Q000166:cytology / Q000378:metabolism*
chemical_list: C448022:gonadotropin-releasing hormone-III; D007987:Gonadotropin-Releasing Hormone; D011761:Pyrrolidonecarboxylic Acid
keywords: Central nervous system; Gonadotropin-releasing hormone; Immunofluorescence; Portunus pelagicus; Spermatogenesis