Spermatogonial stem cells derived from infertile Wv/Wv mice self-renew in vitro and generate progeny following transplantation.
Loss-of-function mutation of the Kit gene causes a severe defect in spermatogenesis that results in infertility due to the inability of its cognate ligand, KIT ligand (KITL), to stimulate spermatogonial proliferation and differentiation. Although self-renewal of mouse spermatogonial stem cells (SSCs) depends on glial cell line-derived neurotrophic factor (GDNF), there is no unequivocal evidence that SSCs with a KIT deficiency can self-renew in vivo or in vitro. In the testis of W(v)/W(v) mice, in which the KIT tyrosine kinase activity is impaired, spermatogonia with SSC phenotype were identified. When W(v)/W(v) spermatogonia were cultured in an SSC culture system supplemented with GDNF in a 10% O(2) atmosphere, they formed clumps and proliferated continuously. An atmosphere of 10% O(2) was better than 21% O(2) to support SSC self-renewal. When W(v)/W(v) clump-forming germ cells were transplanted into testes of infertile wild-type busulfan-treated mice, they colonized the seminiferous tubules but did not differentiate. However, when transplanted into the testes of infertile W/W(v) pups, they restored spermatogenesis and produced spermatozoa, and progeny were generated using microinsemination. These results clearly show that SSCs exist in W(v)/W(v) testes and that they proliferate in vitro similar to wild-type SSCs, indicating that a functional KIT protein is not required for SSC self-renewal. Furthermore, the results indicate that a defect of KIT/KITL signaling of W(v)/W(v) SSCs does not prevent spermatogonial differentiation and spermatogenesis in some recipient strains.
Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Hiroshi
H
Kubota
Mary R
MR
Avarbock
Jonathan A
JA
Schmidt
Ralph L
RL
Brinster
D000704:Analysis of Variance; D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D053222:Fas Ligand Protein / Q000172:deficiency; D005260:Female; D005434:Flow Cytometry; D007246:Infertility / Q000235:genetics / Q000503:physiopathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D010100:Oxygen; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000502:physiology*; D012671:Seminiferous Tubules / Q000166:cytology; D013091:Spermatogenesis / Q000235:genetics; D013093:Spermatogonia / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D013737:Testis / Q000166:cytology; D001616:beta-Galactosidase / Q000235:genetics
D053222:Fas Ligand Protein; D019009:Proto-Oncogene Proteins c-kit; D001616:beta-Galactosidase; D010100:Oxygen