Different approaches to establish infertile rooster

- Radiation therapy and busulfan are appropriate for making an infertile recipient rooster for SSC transplantation studies.
- The 30 Gy (3 × 10 Gy) and 50 mg (30 + 20) are appropriate for suppression of endogenous spermatogenesis in mature roosters.
- There were no significant differences between gamma radiation and busulfan treatments in progressive, total motility of sperm reduction, diameter of seminiferous tubules and thickness of epithelium.

Several methods have been developed to suppress spermatogenesis in recipient males before spermatogonial stem cells (SSCs) transplantation. The aim of this study was to compare two different methods of depleting endogenous spermatogenesis in recipient ROSS 308 strain adult roosters. Gamma-radiation and alkylating agent busulfan were utilized to infertilize adult roosters (ROSS 308 strain). Two radiation therapy regimes (based on 60co isotope) were conducted locally to testes using 40 Gy (5 × 8 Gy with three-day intervals) and 30 Gy (3 × 10 Gy with three-day intervals). And two different levels of busulfan 60mg(40 + 20) and 50mg(30 + 20) with 10-day intervals were injected intraperitoneally. The results showed that both radiation therapy regimes and both busulfan levels reduced sperm motility and sperm concentration significantly compared with control group. Moreover, there were no significant differences between gamma radiation and busulfan treatments in progressive and total motility of sperm reduction. Sperm concentration reached to zero at the end of the 4th week of experiment in all treatment groups. Also histological examinations revealed that both treatments could significantly reduce the diameter of seminiferous tubules and thickness of epithelium. None of the treatments had significant effect on body weight in comparison with control group and the health status of experimental roosters remained good throughout the study. Given that, the risk probability of high doses of radiation exposure and busulfan, it can be concluded that the 30 Gy (3 × 10 Gy) and 50 mg (30 + 20) are appropriate for suppression of endogenous spermatogenesis in mature roosters.