title: Characterization of gonadotropic cells during continuous and seasonal spermatogenesis of two freshwater fish species: a histochemical and immunohistochemical study.
abstract: This work describes gonadotropic (GtH) cells and their morphological and immunohistochemical changes during the spermatogenic cycle of Serrasalmus maculatus (continuous spermatogenesis) and Pimelodus maculatus (seasonal spermatogenesis). GtH cells, widely distributed in the proximal pars distalis of the adenohypophysis, were characterized as round-shaped cells with eccentric nucleus, and cytoplasm with basophilic secretory granules and a variable number of vacuoles for both species. Immunohistochemistry against β-follicle-stimulating hormone (Fsh) and β-luteinizing hormone (Lh) in adjacent sections showed two separated GtH-producing cell populations, and a third population where both GtHs are expressed in the same cell for both species. In the seasonal spermatogenesis of P. maculatus, GtH cells seemed to be more abundant during developing and spawning capable phases. In contrast, no cyclic changes were detected in the continuous spermatogenesis of S. maculatus, except for the strong immunoreaction for Fsh and Lh in males with intense spermiogenesis. We conclude that changes reported here might reflect the type of spermatogenic cycle (seasonal or continuous) which are under different regulatory mechanisms (environmental and internal cues) controlling the reproduction in these species.
authors: Department of Morphology, Institute of Biosciences, São Paulo State University, UNESP, Botucatu, Brazil.
authors: Rafael Henrique
authors: RH
authors: Nóbrega
authors: Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, USP, São Paulo, Brazil.
authors: Lázaro Wender Oliveira
authors: LW
authors: de Jesus
authors: Department of Physiology, Institute of Biosciences, University of São Paulo, USP, São Paulo, Brazil.
authors: Renato Massaaki
authors: RM
authors: Honji
authors: Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, USP, São Paulo, Brazil. miborell@usp.br.|Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Professor Lineu Prestes 1524, São Paulo, SP, 05508-000, Brazil. miborell@usp.br.
authors: Maria Inês
authors: MI
authors: Borella
mesh_terms: D000818:Animals; D002397:Catfishes / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology; D060125:Characiformes / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology; D037201:Follicle Stimulating Hormone, beta Subunit / Q000378:metabolism; D037101:Luteinizing Hormone, beta Subunit / Q000378:metabolism; D008297:Male; D010903:Pituitary Gland, Anterior / Q000033:anatomy & histology / Q000166:cytology* / Q000378:metabolism; D012621:Seasons; D013091:Spermatogenesis; D013737:Testis / Q000166:cytology
chemical_list: D037201:Follicle Stimulating Hormone, beta Subunit; D037101:Luteinizing Hormone, beta Subunit
keywords: Adenohypophysis; Gonadotropin; Pituitary gland; Reproduction; Spermatogenesis; Teleostei