Functional assessment of self-renewal activity of male germline stem cells following cytotoxic damage and serial transplantation.
Spermatogenesis is dependent on a small population of stem cells. Although stem cells are believed to expand infinitely, there is little functional evidence regarding whether spermatogonial stem cells can increase in their number. Using the spermatogonial transplantation technique, we evaluated the proliferative potential of spermatogonial stem cells in two models of regeneration. After busulfan injection to deplete stem cells, the surviving stem cells were able to expand by at least 15.8-fold within 2 mo. On the other hand, a serial transplantation study indicated that one transplanted stem cell was able to expand by 3.8- and 12-fold within 2 and 4 mo, respectively. These results provide direct functional evidence for the expansion of stem cells and establish the basis for further characterization of the stem cell self-renewal process.
Kanatsu-Shinohara
Mito
M
Department of Medical Chemistry, Graduate School of Medicine, Kyoto University, Japan.
Toyokuni
Shinya
S
Morimoto
Takeshi
T
Matsui
Shigeyuki
S
Honjo
Tasuku
T
Shinohara
Takashi
T
D000477:Alkylating Agents / Q000633:toxicity*; D000818:Animals; D002066:Busulfan / Q000633:toxicity*; D005854:Germ Cells / Q000187:drug effects / Q000502:physiology*; D049452:Green Fluorescent Proteins; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D007700:Kinetics; D008164:Luminescent Proteins; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012038:Regeneration / Q000187:drug effects / Q000502:physiology*; D013091:Spermatogenesis / Q000502:physiology; D013093:Spermatogonia / Q000187:drug effects / Q000502:physiology; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology*; D013737:Testis / Q000166:cytology / Q000502:physiology
D000477:Alkylating Agents; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D002066:Busulfan