1. Characterization of the gonadotropin-releasing hormone system in the Neotropical teleost, Steindachneridion parahybae during the annual reproductive cycle in captivity
- Author
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Renata Guimarães Moreira, Renato Massaaki Honji, Danilo Caneppele, Fabiana Laura Lo Nostro, Matías Pandolfi, Universidade de São Paulo (USP), Universidade Estadual Paulista (Unesp), Rodovia dos Tamoios, and Ciudad Universitaria (C1428EHA)
- Subjects
medicine.medical_specialty ,Pituitary gland ,Hypothalamus ,Captivity ,030209 endocrinology & metabolism ,Gonadotropin-releasing hormone ,Biology ,Gonadotropin-Releasing Hormone ,03 medical and health sciences ,Diencephalon ,0302 clinical medicine ,Endocrinology ,Internal medicine ,medicine ,Animals ,Protein Precursors ,Seasonal reproduction ,Catfishes ,030304 developmental biology ,Cell Nucleus ,Neurons ,0303 health sciences ,Reproduction dysfunction ,Cerebrum ,Reproduction ,HIPOTÁLAMO ,Brain ,Olfactory bulb ,medicine.anatomical_structure ,GnRH ,Pituitary Gland ,Animal Science and Zoology ,Female ,Vitellogenesis - Abstract
Made available in DSpace on 2018-12-11T17:20:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) This study evaluated by immunohistochemical and Western blot methods, the distribution of two distinct gonadotropin-releasing hormones (GnRHs), corresponding to catfish GnRH (cfGnRH or GnRH1) and chicken-II GnRH (cGnRH-II or GnRH2), in Steindachneridion parahybae females in captivity, focusing these analyses on the reproductive cycle by semi-quantification of optical density (OD). Further, we found that the GnRH neuronal systems co-localized with their respective GnRH-associated peptides (GAPs). A group of neurons immunoreactive (ir) to GnRH1 were identified along the ventral region of the olfactory bulb (vOB) in the telencephalon (vTel) and in the main areas of the diencephalon (especially the medial basal hypothalamus, HBM), including fibers extending into the pituitary gland. In contrast, GnRH2 neurons were confined to the midbrain tegmentum, close to the ventricular surface, without projections to the pituitary gland. Moreover, a cfGAP (GnRH1)-specific band (9 kDa) was identified in the brain and pituitary gland, while a cGAP-II (GnRH2)-specific band (26 kDa) was observed only in the brain extract. During the reproductive cycle, GnRH1-ir presented greater OD values at the vitellogenic and regression stages than at the previtellogenic stage and after artificially induced to spawn. Larger GnRH2-ir neurons were observed during the reproductive cycle, but a higher OD was identified only in the regression stage compared with the other maturation stages. Finally, GnRH1 axons were found to be directed towards the pituitary, and this GnRH type, which is probably the hypophysiotropic form, can contribute to the reproductive dysfunction that occurs in S. parahybae females in captivity, whereas GnRH2 may act as a neuromodulator and/or neurotransmitter. Departamento de Fisiologia Instituto de Biociências Universidade de São Paulo, Rua do Matão, Travessa 14, 321 Centro de Aquicultura Universidade Estadual Paulista (UNESP), Campus de Jaboticabal, Via de Acesso Prof. Paulo Donato Castellane, S/N, 14884-900, Jaboticabal Companhia Energética de São Paulo (CESP) Unidade de Hidrobiologia e Aquicultura Rodovia dos Tamoios, km 38. 12260-000 Departamento de Biodiversidad y Biología Experimental Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires & IBBEA CONICET-UBA Ciudad Universitaria (C1428EHA) Centro de Aquicultura Universidade Estadual Paulista (UNESP), Campus de Jaboticabal, Via de Acesso Prof. Paulo Donato Castellane, S/N, 14884-900, Jaboticabal FAPESP: 2008/57687-0
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- 2018