title: Depletion of testis cell populations in pre-pubertal Bos indicus cattle by irradiation.
abstract: Recovery of spermatogenesis following a single dose of irradiation was evaluated in pre-pubertal Brahman bulls, after receiving a single dose of 3, 6, 9 or 12Gray (Gy) irradiation. Biopsy samples of testis tissue were collected and processed for immunohistology at various times following irradiation. Spermatogenic recovery was defined by the changes in tubule diameter, and absolute numbers of undifferentiated spermatogonia (PLZF positive cells) and Sertoli cells (GATA-4 positive cells) per tubule cross section. The effect of irradiation on the depletion of testicular cells was dose-dependent. Immunohistological results from both the 9 and 12Gy group showed degeneration of seminiferous tubules, compared with other doses and controls. From 2 weeks after the treatment, irradiation resulted in a significant and dramatic reduction in tubule diameter (up to 40%), number of undifferentiated spermatogonia (up to 90%) and Sertoli cells (up to 70%), which was sustained for up to 16 weeks post-irradiation in 9 and 12Gy groups (P<0.0001). However, a moderate depletion effect was observed in the 6Gy treatment groups, compared with 9 and 12Gy doses. The 6Gy treatment had significant effects on spermatogonia (up to 79% reduction) and Sertoli cell (30% reduction) numbers following irradiation (P<0.0001). In contrast, the 3Gy dose had no significant effect at either 3 or 5 weeks post-irradiation on tubule diameter, spermatogonia or Sertoli cells. In conclusion, the results from the current study suggest that treatment of recipient testes with a single dose of 6Gy irradiation can temporarily deplete spermatogonial cells in pre-pubertal Brahman bulls, whilst minimising the impact on Sertoli cells and tubule morphology.
authors.affiliation: CSIRO Food Futures National Research Flagship, Sydney, NSW 2113, Australia; CSIRO Animal, Food and Health Sciences, FD McMaster Laboratory, Armidale, NSW 2350, Australia.
authors.forename: Muren
authors.initials: M
authors.lastname: Herrid
authors.forename: Rhonda
authors.initials: R
authors.lastname: Davey
authors.forename: Sally
authors.initials: S
authors.lastname: Stockwell
authors.forename: Sabine
authors.initials: S
authors.lastname: Schmoelzl
authors.forename: Grant
authors.initials: G
authors.lastname: Uphill
authors.forename: Valerie
authors.initials: V
authors.lastname: Poirier
authors.forename: Michelle
authors.initials: M
authors.lastname: Hope
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Hill
authors.forename: Michael K
authors.initials: MK
authors.lastname: Holland
authors.forename: Sigrid A
authors.initials: SA
authors.lastname: Lehnert
mesh_terms: D000818:Animals; D002417:Cattle; D004307:Dose-Response Relationship, Radiation; D008297:Male; D012611:Scrotum / Q000528:radiation effects; D012741:Sexual Maturation / Q000528:radiation effects*; D013091:Spermatogenesis / Q000528:radiation effects; D013737:Testis / Q000166:cytology* / Q000528:radiation effects*
keywords: Bos indicus; Depletion; Irradiation; Sertoli cells; Undifferentiated spermatogonia