title: Apoptosis and proliferation in the testes of the brown hare (Lepus europaeus) under the influence of photoperiod.
abstract: Brown hare is a seasonal breeding mammal and under the influence of photoperiod the spermatogenesis ceases during autumn months - most markedly in September and October. Testis samples from 34 animals, sacrificed between July and December were fixed in Bouin solution, embedded in paraffin, subjected to immunohistochemistry and analysed by light microscopy. TUNEL (terminal deoxynucleotidyl transferase-mediated d'UTP nick end labeling) method was applied to detect apoptosis, anti PCNA (proliferating cell nucleolar antigen) antibodies were used to evaluate cell proliferation and antibodies against apolipoprotein D and 3beta-HSD (3beta-hidroxysteroid dehydrogenase) to evaluate the activity of the Leydig cells. Our results show that the apoptotic processes in seminiferous epithelium are obvious in August and reach peak in September, with cell death occurring during prophase of I meiotic division. In July, and from early November onwards only occasional TUNEL positive cells can be seen. The proliferation of the germ cells continues also during phase of regression (September, October and early November). Active testosterone producing Leydig cells appear to be absent in September, whereas their activity becomes obvious in the middle of November.
authors.affiliation: Institute for Anatomy, Histology and Embryology, Veterinary Faculty, University of Ljubljana, Slovenia.
authors.forename: M
authors.initials: M
authors.lastname: Strbenc
authors.forename: S V
authors.initials: SV
authors.lastname: Bavdek
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002455:Cell Division / Q000502:physiology; D020287:In Situ Nick-End Labeling; D007793:Lagomorpha; D007985:Leydig Cells / Q000737:chemistry / Q000502:physiology; D008297:Male; D017440:Photoperiod; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D012621:Seasons; D013090:Spermatocytes / Q000166:cytology; D013093:Spermatogonia / Q000166:cytology; D013737:Testis / Q000166:cytology* / Q000502:physiology*
chemical_list: D018809:Proliferating Cell Nuclear Antigen