title: Derivation of developmentally competent oocytes by the culture of preantral follicles retrieved from adult ovaries: maturation, blastocyst formation, and embryonic stem cell transformation.
abstract: OBJECTIVE
  To determine whether the preantral follicles in adult ovaries can generate developmentally competent oocytes after in vitro culture.
  
  
  METHODS
  Prospective, animal-model study.
  
  
  METHODS
  Gamete and Stem Cell Biotechnology Laboratory, Seoul National University, Seoul, Korea.
  
  
  METHODS
  B6CBAF1 mice.
  
  
  METHODS
  Preantral follicles collected from 8-week-old mice were cultured in vitro.
  
  
  METHODS
  Follicle development, embryogenesis, and embryonic stem cell characterization.
  
  
  RESULTS
  A mean of 50.3 preantral follicles were retrieved from one adult animal, which is significantly less than the number (88.7 follicles) retrieved from a prepubertal female. Extension of the culture period greatly improved oocyte maturation; increased follicular growth to the pseudo-antral (89%-91% vs. 32%) or mature oocyte stage (65%-77% vs. 13%) was observed after 12 or 13 days of culture compared with 9 days of culture. Blastocyst formation after parthenogenesis was detected in only one case; in comparison, the use of IVF yielded a large number of embryos that developed into blastocysts. A mean of 14.7 intrafollicular oocytes per animal were produced after 13 days of culture, and 41% of those developed into blastocysts after IVF. Embryonic stem cell-like colonies were established by subculturing the inner cell mass cells from the blastocysts.
  
  
  CONCLUSIONS
  Developmentally competent oocytes can be generated by culturing adult preantral follicles. These results may help increase the feasibility of follicle culture systems.
authors.affiliation: Gamete and Stem Cell Biotechnology Laboratory, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea.
authors.forename: In Wook
authors.initials: IW
authors.lastname: Kim
authors.forename: Seung Pyo
authors.initials: SP
authors.lastname: Gong
authors.forename: Cho Rong
authors.initials: CR
authors.lastname: Yoo
authors.forename: Jun Hee
authors.initials: JH
authors.lastname: Choi
authors.forename: Dae Yong
authors.initials: DY
authors.lastname: Kim
authors.forename: Jeong Mook
authors.initials: JM
authors.lastname: Lim
mesh_terms: D000367:Age Factors; D000818:Animals; D001755:Blastocyst / Q000502:physiology; D018929:Cell Culture Techniques; D002461:Cell Line, Transformed; D002469:Cell Separation / Q000379:methods; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D002478:Cells, Cultured; D047108:Embryonic Development / Q000502:physiology*; D053595:Embryonic Stem Cells / Q000473:pathology* / Q000502:physiology; D005240:Feasibility Studies; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009865:Oocytes / Q000166:cytology* / Q000502:physiology; D006080:Ovarian Follicle / Q000166:cytology*; D010053:Ovary / Q000166:cytology; D010312:Parthenogenesis / Q000502:physiology*