Translating Spermatogonial Stem Cell Transplantation to the Clinic - Male Germline Stem Cells Developmental and Regenerative Potential - page 237

Fig. 11.2 Busulfan conditioning to generate an infertile recipient model. ( a ) To assess the effects
of busulfan chemotherapy on spermatogenesis, sperm counts were measured weekly after treat-
ment at doses of 0-12 mg/kg. Mortality was observed with animals treated at the higher doses of
busulfan (8 and 12 mg/kg, yellow and blue arrowheads ). ( b ) Hematoxylin & eosin staining was
used to evaluate the effects of busulfan treatment on the extent of spermatogenesis in experimen-
tal animals before or after treatment. Scale bar = 50 mm. As noted ( black arrow below x-axis),
busulfan was administered at week 0. Note: samples for week 0 were collected prior to busulfan
administration. Modified from (Hermann et al. 2007 )
the resulting patches of spermatogonia are maintained long-term, and thus, may
constitute a bioassay for primate SSCs that is more experimentally tractable than
primate-to-primate transplantation. While normal adult rhesus testis cells produced
4.64 colonies/10 6 viable cells, testis cells isolated from males more than one year
following high-dose busulfan treatment failed to produce any colonies of
spermatogonia in the xenotransplantation assay (Hermann et al. 2007 ). The conclu-
sion from these data was that high-dose busulfan treatment depleted SSCs in rhesus
testes, resulting in a loss of endogenous spermatogenesis.