title: The seminiferous epithelium cycle and daily spermatic production in the adult maned wolf (Chrysocyon brachyurus, Illiger, 1811).
abstract: The duration of the seminiferous epithelium cycle was estimated in adult maned wolves (Chrysocyon brachyurus, Illiger, 1811), by applying intratesticular injections with tritiated thymidine. The total duration of the seminiferous epithelium cycle in this species was calculated in 8.99 days. So, taking into account that approximately 4.5 cycles of the seminiferous epithelium are necessary for the whole spermatogenesis process to complete, the production of spermatozoa from one spermatogonia will take about 40.45 days. The duration of the spermiogenesis was calculated to be 12.3 days. The eight stages of the seminiferous epithelium cycle were described by the tubular morphology method, which is based either on the form and position of the spermatid nuclei and the occurrence of meiotic divisions. The values of the relative frequency for the pre-meiotic, meiotic and post-meiotic phases in this species were 3.5, 0.78 and 4.8 days, respectively. The maned wolf produces about 29 million spermatozoa a day for each testis gram, therefore being classified among the species provided with a high spermatogenetic efficiency.
authors.affiliation: Veterinary Department, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors.forename: Viviane Lewicki
authors.initials: VL
authors.lastname: Bitencourt
authors.forename: Tarcízio Antônio Rego
authors.initials: TA
authors.lastname: de Paula
authors.forename: Sérgio Luis Pinto
authors.initials: SL
authors.lastname: da Matta
authors.forename: Cláudio César
authors.initials: CC
authors.lastname: Fonseca
authors.forename: Laércio
authors.initials: L
authors.lastname: dos Anjos Benjamin
authors.forename: Deiler Sampaio
authors.initials: DS
authors.lastname: Costa
mesh_terms: D000818:Animals; D046028:Canidae / Q000502:physiology*; D008297:Male; D008853:Microscopy / Q000379:methods; D012670:Seminiferous Epithelium / Q000502:physiology* / Q000648:ultrastructure; D012708:Sertoli Cells / Q000502:physiology / Q000648:ultrastructure; D013087:Spermatids / Q000502:physiology / Q000648:ultrastructure; D013090:Spermatocytes / Q000502:physiology / Q000648:ultrastructure; D013091:Spermatogenesis / Q000502:physiology*; D013093:Spermatogonia / Q000502:physiology / Q000648:ultrastructure; D013094:Spermatozoa / Q000502:physiology / Q000648:ultrastructure; D013737:Testis / Q000502:physiology