title: Morphofunctional changes of female germinal epithelium to support spermatozoa along the annual reproductive cycle in an inseminating catfish (Trachelyopterus galeatus, Auchenipteridae).
abstract: The reproductive system of some fish species presents elaborate mechanisms by which the females store spermatozoa inside their ovaries, keeping them viable for fertilization for an extended period of time. However, as intriguing as this sperm storage is, it is not yet understood how the sperm can remain viable in the ovary. Aiming to understand this phenomenon, the epithelium covering the ovarian lamellae, that is, the germinal epithelium, of the Cangati (Trachelyopterus galeatus), an inseminating catfish, was evaluated taking into account the different stages of the annual reproductive cycle. The germinal epithelium morphology changed during the annual reproductive cycle, presumably in preparation to receive the spermatozoa and keep them viable until fertilization. There was a progressive increase of the epithelium height. Also the number of intercellular junctions, desmosomes, and extended tight junctions, apparently increased forming chains that could be regarded as a barrier to isolate the sperm from the female immune system. Synthetic organelles were active releasing cytoplasmic granules and secretion in the epithelial enfolds in which the spermatozoa were deeply embedded. Concomitantly, oogonium nests were formed in the germinal epithelium during early folliculogenesis.
authors.affiliation: Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brasil.
authors.forename: Hélio
authors.initials: H
authors.lastname: Chiarini-Garcia
authors.forename: Francisco O
authors.initials: FO
authors.lastname: Vieira
authors.forename: Hugo P
authors.initials: HP
authors.lastname: Godinho
mesh_terms: D000818:Animals; D002397:Catfishes / Q000033:anatomy & histology / Q000502:physiology*; D002470:Cell Survival; D004848:Epithelium / Q000502:physiology; D005260:Female; D005306:Fertilization; D007314:Insemination; D008297:Male; D010053:Ovary / Q000033:anatomy & histology / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology* / Q000502:physiology
keywords: basement membrane; inseminating fish; oogonia; ovarian lamella; spermatozeugma