title: Cellular organisation of the mature testes and stages of spermiogenesis in Danio rerio (Cyprinidae; Teleostei)--structural and ultrastructural studies.
abstract: The male gonads of Danio rerio occupy a position typical of the Teleostei species. The structure of the testes corresponds to the anastomosing tubular type with unrestricted spermatogonia and represents a cystic type of spermatogenesis. The results of this study indicate that four distinct stages of cell differentiation can be identified during spermiogenesis. These stages are characterised by chromatin condensation, the development of flagellum, nuclear rotation, the formation of nuclear fossa and the elimination of excess cytoplasm. A round head and the absence of an acrosome characterise the differentiated sperm. The midpiece is short and large, and C-shaped mitochondria form a ring surrounding the initial region of the flagellum. The axoneme shows a 9+2 pattern. In the D. rerio spermatozoa the flagellar axis is at an angle of 110° to the nucleus diameter running through the centriole.
authors: Department of Animal Histology and Embryology, University of Silesia, Bankowa 9, 40-007 Katowice, Poland. weronika.rupik@us.edu.pl
authors: W
authors: W
authors: Rupik
authors: J
authors: J
authors: Huszno
authors: J
authors: J
authors: Klag
mesh_terms: D000818:Animals; D008297:Male; D008854:Microscopy, Electron; D013091:Spermatogenesis; D013737:Testis / Q000166:cytology* / Q000502:physiology*; D015027:Zebrafish / Q000033:anatomy & histology* / Q000502:physiology*