title: [Application of chemical activation to in vitro fertilization by round spermatid injection in mice].
abstract: OBJECTIVE
  To search for an optimal activation protocol by comparing the chemical activation effects of single-activator and combined activation protocols on mouse oocytes following injection of round spermatids (ROSI) from spermatogenic cells cultured in vitro.
  
  
  METHODS
  Using different concentrations of ethanol, ionomycin (Ion), calcium ionophore A23187 (CIA), strontium chloride (SrCl2), cycloheximide (CHX), and 6-dimethylaminopurine (6-DMAP) , we activated post-ROSI oocytes for different times, and activated them by combined protocols at optimal concentrations and action times according to different activation channels. We compared the activation effects of single-activator and combined activation protocols by comparing the rates of fertilization, cleavages, and morulas and blastocysts.
  
  
  RESULTS
  With a single activator, the optimal protocols of different activators were as follows: 7% ethanol for 6 min, 5 micromol/L CIA for 5 min, 5 micromol/L Ion for 5 min, 2 mmol/L 6-DMAP for 2 h, 10 mmol/L SrCl2 for 1.5 h, and 10 microg/ml CHX for 1.5 h, among which 10 mmol/L SrCl2 for 1.5 h achieved the highest rate of morulas and blastocysts, significantly better than CHX (P < 0.05) but with no remarkable difference from other activators. The ethanol + 6-DMAP group showed a significantly higher rate of morulas and blastocysts (29.63%) than all other combined activation groups and single-activator groups except SrCl2 (P < 0.05), and it also exhibited higher rates of normal fertilization, cleavages and morula than the SrCl2 group, but with no significant difference.
  
  
  CONCLUSIONS
  The single-activator 10 mmol/L SrCl2 for 1.5 h and the combined activation of 7% ethanol for 6 min + 2 mmol/L 6-DMAP for 2 h are the optimal protocols for chemical activation of mouse oocytes following ROSI, and the combined activation of ethanol + 6-DMAP is even superior to the single-activator protocol.
authors: Center of Reproductive Medicine, The 105th Hospital of PLA, Hefei, Anhui 230031, China. huangj105@163.com
authors: Jing
authors: J
authors: Huang
authors: Center of Reproductive Medicine, The 105th Hospital of PLA, Hefei, Anhui 230031, China.
authors: Hong
authors: H
authors: Jiang
authors: Center of Reproductive Medicine, The 105th Hospital of PLA, Hefei, Anhui 230031, China.
authors: Cun-Li
authors: CL
authors: Wang
authors: Center of Reproductive Medicine, The 105th Hospital of PLA, Hefei, Anhui 230031, China.
authors: Xiao-Min
authors: XM
authors: Song
mesh_terms: D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D005260:Female; D005307:Fertilization in Vitro; D015759:Ionomycin / Q000494:pharmacology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009865:Oocytes / Q000166:cytology / Q000187:drug effects; D013087:Spermatids / Q000166:cytology* / Q000187:drug effects*
chemical_list: D015759:Ionomycin; D003513:Cycloheximide