title: Simultaneous injection of round spermatid nuclei from mice and hamster oscillogen can initiate the normal development of mouse embryos.
abstract: OBJECTIVE
  In the mouse, mature oocytes that have been injected with spermatid nuclei failed to become activated. Additional stimulation is required to trigger activation of the oocytes that leads to embryo development. This study was performed to determine whether simultaneous injection of mouse round spermatids and hamster oscillogen can fertilize oocytes and contribute to normal embryo development.
  
  
  METHODS
  We simultaneously injected mouse oocytes with mouse round spermatid nuclei and a preparation of oocyte-activating protein (oscillogen) from hamster spermatozoa and compared the results with those of injection of testicular spermatozoa.
  
  
  RESULTS
  The incidence of normal fertilization and embryo development after simultaneous injection of round spermatid nuclei and hamster oscillogen was not significantly different from that after the injection of testicular spermatozoa. Moreover, the rate of development of two-cell embryos to term did not differ very much between the two groups of oocytes.
  
  
  CONCLUSIONS
  Simultaneous injection of round spermatid nuclei and oscillogen appears to be an ideal method for successful activation of oocytes by spermatid nuclei in vitro.
authors.affiliation: Department of Urology, Yamagata University School of Medicine, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Sasagawa
authors.forename: M
authors.initials: M
authors.lastname: Tomaru
authors.forename: Y
authors.initials: Y
authors.lastname: Adachi
authors.forename: Y
authors.initials: Y
authors.lastname: Kubota
authors.forename: T
authors.initials: T
authors.lastname: Nakada
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins; D002467:Cell Nucleus; D006224:Cricetinae; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D007267:Injections; D008297:Male; D051379:Mice; D009865:Oocytes; D011506:Proteins / Q000008:administration & dosage*; D013087:Spermatids / Q000648:ultrastructure*
chemical_list: D002135:Calcium-Binding Proteins; D011506:Proteins; C097705:oscillin