Anchorage-independent growth of mouse male germline stem cells in vitro.
Spermatogenesis originates from a small number of spermatogonial stem cells that reside on the basement membrane and undergo self-renewal division to support spermatogenesis throughout the life of adult animals. Although the recent development of a technique to culture spermatogonial stem cells allowed reproduction of self-renewal division in vitro, much remains unknown about how spermatogonial stem cells are regulated. In this study, we found that spermatogonial stem cells could be cultured in an anchorage-independent manner, which is characteristic of stem cells from other types of self-renewing tissues. Although the cultured cells grew slowly (doubling time, approximately 4.7 days), they expressed markers of spermatogonia, and grew exponentially for at least 5 months to achieve 1.5 x 10(10) -fold expansion. The cultured cells underwent spermatogenesis following transplantation into the seminiferous tubules of infertile animals and fertile offspring were obtained by microinsemination of germ cells that had developed within the testes of recipients of the cultured cells. These results indicate that spermatogonial stem cells can undergo anchorage-independent, self-renewal division, and suggest that stem cells have the common property to survive and proliferate in the absence of exogenous substrata.
Kanatsu-Shinohara
Mito
M
Horizontal Medical Research Organization, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan. mshinoha@virus.kyoto-u.ac.jp
Inoue
Kimiko
K
Lee
Jiyoung
J
Miki
Hiromi
H
Ogonuki
Narumi
N
Toyokuni
Shinya
S
Ogura
Atsuo
A
Shinohara
Takashi
T
D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation; D002478:Cells, Cultured; D005260:Female; D006085:Graft Survival / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011247:Pregnancy; D012671:Seminiferous Tubules / Q000166:cytology; D012708:Sertoli Cells / Q000166:cytology; D013090:Spermatocytes / Q000166:cytology*; D013091:Spermatogenesis / Q000502:physiology*; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology*
D049452:Green Fluorescent Proteins