title: Clonal origin of germ cell colonies after spermatogonial transplantation in mice.
abstract: Spermatogenesis originates from a small number of spermatogonial stem cells that can reinitiate spermatogenesis and produce germ cell colonies following transplantation into infertile recipient testes. Although several previous studies have suggested a single-cell origin of germ cell colonies, only indirect evidence has been presented. In this investigation, we tested the clonal origin hypothesis using a retrovirus, which could specifically mark an individual spermatogonial stem cell. Spermatogonial stem cells were infected in vitro with an enhanced green fluorescence protein-expressing retrovirus and subsequently transplanted into infertile recipient mice. Live haploid germ cells were recovered from individual colonies and were microinjected into eggs to create offspring. In total, 45 offspring were produced from five colonies, and 23 (51%) of the offspring were transgenic. Southern blot analysis indicated that the transgenic offspring from the single colony carried a common integration site, and the integration site was different among the transgenic offspring from different colonies. These results provide evidence that germ cell colonies develop from single spermatogonial stem cells.
authors.affiliation: Horizontal Medical Research Organization, Department of Molecular Genetics, Kyoto University, Japan. mshinoha@virus.kyoto-u.ac.jp
authors.forename: Mito
authors.initials: M
authors.lastname: Kanatsu-Shinohara
authors.forename: Kimiko
authors.initials: K
authors.lastname: Inoue
authors.forename: Hiromi
authors.initials: H
authors.lastname: Miki
authors.forename: Narumi
authors.initials: N
authors.lastname: Ogonuki
authors.forename: Masanori
authors.initials: M
authors.lastname: Takehashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Morimoto
authors.forename: Atsuo
authors.initials: A
authors.lastname: Ogura
authors.forename: Takashi
authors.initials: T
authors.lastname: Shinohara
mesh_terms: D000818:Animals; D002999:Clone Cells / Q000166:cytology*; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics; D007314:Insemination; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D012190:Retroviridae / Q000235:genetics / Q000502:physiology; D013091:Spermatogenesis; D013093:Spermatogonia / Q000166:cytology*; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology*
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins