title: Proliferation of mouse spermatogonial stem cells in microdrop culture.
abstract: It is now possible to make mouse spermatogonial stem cells (SSCs) proliferate in vitro. However, these cultured cells, called germ-line stem (GS) cells, consist of not only SSCs but also a greater number of progenitor spermatogonia. Moreover, isolated GS cells barely proliferate. To elucidate the nature of SSCs and progenitor spermatogonia, we adapted a microdrop culture system to GS cells. Using a micromanipulator, individual microdrops were seeded with clusters or dissociated known numbers of GS cells. The number of surviving colonies was determined after 30 days. The proliferation rate of GS cells in microdrops increased as the number of GS cells seeded increased. It was observed that as few as three GS cells seeded in a microdrop can proliferate and expand the colony size. Those GS cells of expanded colonies were able to proliferate following subculture and underwent spermatogenesis in the host testis after transplantation into the seminiferous tubules of recipient mice. These data revealed that SSCs can multiply in a microdrop culture system. Microdrop culture offers a novel tool to elucidate the nature of SSCs in regard to their self-renewing capacity and can serve as a monitoring system of culture conditions for the self-renewal of SSCs.
authors: The Institute for Advanced Reproductive Medical Technology, Maebashi, Gunma, Japan. yaaraki@nifty.com
authors: Yasuyuki
authors: Y
authors: Araki
authors: Takuya
authors: T
authors: Sato
authors: Kumiko
authors: K
authors: Katagiri
authors: Yoshinobu
authors: Y
authors: Kubota
authors: Yasuhisa
authors: Y
authors: Araki
authors: Takehiko
authors: T
authors: Ogawa
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D002478:Cells, Cultured; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D012671:Seminiferous Tubules / Q000166:cytology; D013091:Spermatogenesis; D013093:Spermatogonia / Q000166:cytology* / Q000254:growth & development / Q000637:transplantation; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology*; D013997:Time Factors
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins