Transduction and transplantation of spermatogonia into the testis of ram lambs through the extra-testicular rete.
Spermatogonial transplantation will provide a new way to study spermatogenesis in domestic animals, disseminate male genetics and produce transgenic animals, if efficiency can be improved. We evaluated a 'surgical' method for transplanting donor cells into testes of ram lambs, where the head of the epididymis is reflected, and a catheter introduced into the extra-testicular rete testis. We also tested transduction of ram spermatogonia with a lentiviral (LV) vector as a means to identify permanent colonization, and introduce genes into donor cells. Eight ram lambs, 11- to 13-week olds, were the recipients: in five, spermatogonia were injected into one testis, and the contralateral testis was an un-manipulated control: in two, spermatogonia were injected into one testis and the contralateral was sham-injected: in one, both testes were injected. Six lambs received spermatogonia labelled with a cell-tracking dye and these were collected 1 or 2 weeks after transplantation; three lambs received spermatogonia transduced with a LV vector driving the expression of enhanced Green Fluorescence Protein and these were collected after 2 months. Donor cells were detected by immunohistochemistry in tubules of seven of nine recipient testes. Approximately 22% of tubule cross-sections contained donor cells immediately after transplantation, and 0.2% contained virally transduced cells 2 months after transplantation. The onset of spermatogenesis was delayed, and there were lesions in both injected and sham-injected testes. Despite the effects of the surgery, elongated spermatids were present in one recipient testis 2 months after surgery. The results suggest that, after modifying the surgical and transduction techniques, this approach will be a means to produce good colonization by donor spermatogonia in sheep testes.
Rodriguez-Sosa
J R
JR
Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Canada.
Silvertown
J D
JD
Foster
R A
RA
Medin
J A
JA
Hahnel
A
A
D000818:Animals; D002470:Cell Survival; D015870:Gene Expression; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000235:genetics; D007150:Immunohistochemistry / Q000662:veterinary; D016086:Lentivirus / Q000235:genetics / Q000254:growth & development; D008297:Male; D012152:Rete Testis; D012671:Seminiferous Tubules / Q000166:cytology; D012756:Sheep; D013091:Spermatogenesis; D013093:Spermatogonia / Q000378:metabolism* / Q000637:transplantation*; D014161:Transduction, Genetic / Q000662:veterinary*
C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins