title: Mouse oocytes injected with cryopreserved round spermatids can develop into normal offspring.
abstract: OBJECTIVE
  This study was performed to determine whether frozen-thawed mouse round spermatids can fertilize oocytes and contribute to normal embryo development.
  
  
  METHODS
  Freshly collected mouse testicular cells were frozen in PBS containing 7.5% glycerol and 7.5% fetal bovine serum. After thawing and removal of the cryoprotectants, round spermatids were selected and injected individually into mature oocytes which had been previously activated with Sr(2+)-containing Ca(2+)-free medium.
  
  
  RESULTS
  After thawing, 75-85% of testicular cells were alive. About 90% of the oocytes were fertilized by intracytoplasmic injection of frozen-thawed round spermatids; 11% (17/150) of embryos transferred to foster mothers developed into normal offspring.
  
  
  CONCLUSIONS
  Mouse round spermatids can be cryopreserved for production of normal offspring.
authors: Department of Veterinary Science, National Institute of Health, Tokyo, Japan.
authors: A
authors: A
authors: Ogura
authors: J
authors: J
authors: Matsuda
authors: T
authors: T
authors: Asano
authors: O
authors: O
authors: Suzuki
authors: R
authors: R
authors: Yanagimachi
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D004624:Embryo Transfer; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009865:Oocytes / Q000502:physiology*; D013084:Sperm-Ovum Interactions; D013087:Spermatids / Q000502:physiology*