title: Functional assessment of self-renewal activity of male germline stem cells following cytotoxic damage and serial transplantation.
abstract: 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.
authors.affiliation: Department of Medical Chemistry, Graduate School of Medicine, Kyoto University, Japan.
authors.forename: Mito
authors.initials: M
authors.lastname: Kanatsu-Shinohara
authors.forename: Shinya
authors.initials: S
authors.lastname: Toyokuni
authors.forename: Takeshi
authors.initials: T
authors.lastname: Morimoto
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Matsui
authors.forename: Tasuku
authors.initials: T
authors.lastname: Honjo
authors.forename: Takashi
authors.initials: T
authors.lastname: Shinohara
mesh_terms: 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
chemical_list: D000477:Alkylating Agents; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D002066:Busulfan