title: [Effects of different electrofusion parameters on activation and early development of mouse embryos reconstructed by cumulus cell nuclear transfer].
abstract: OBJECTIVE
  To study the effects of different parameters for electrofusion on the activation and early development of mouse embryos reconstructed by cumulus cell nuclear transfer, and explore optimal parameters for electrofusion.
  
  
  METHODS
  A C57BL/6j mouse cumulus cell nucleus 10-12 mm in diameter was inserted into the perivitelline space of an enucleated oocyte. The fusion of donor-recipient pairs was induced with different parameters for electrofusion (with variation in electric field intensity, pulse duration and pulse times). Successful formation of the reconstructed embryos from donor-recipient pairs and the reconstructed embryos developing into the early embryonic stages (2-cell, 4-8-cell and morula stages) were observed and counted.
  
  
  RESULTS
  The electric field intensity and pulse duration allowed variation during electrofusion within the range of 1 000-2 000 kV/cm and 40-160 ms, respectively. The donor-recipient pairs fused at very low rate when the parameters were below the allowed ranges, and disintegration or even death might occur when the parameters were above the ranges. Within these allowed ranges, variation of the electrofusion parameters did not produce significant impact on the ratio of the reconstructed embryos in 2-cell, 4-8-cell or morula stages (P<0.05). In addition, we suggested that pulse times be limited to 1-2.
  
  
  CONCLUSIONS
  Optimal parameters for electrofusion are crucial for the fusion of donor-recipient pairs and the activation of the reconstructed embryo.
authors.affiliation: Institute of Cancer Research, Southern Medical University, Guangzhou 510515, China. jpzgmdxx@fimmu.com
authors.forename: Pei-Zhou
authors.initials: PZ
authors.lastname: Jiang
authors.forename: Xin-Ming
authors.initials: XM
authors.lastname: Shen
authors.forename: Gui-Lin
authors.initials: GL
authors.lastname: Qiao
authors.forename: Hua
authors.initials: H
authors.lastname: Huang
authors.forename: Kai-Tai
authors.initials: KT
authors.lastname: Yao
mesh_terms: D000818:Animals; D002459:Cell Fusion / Q000379:methods; D004622:Embryo, Mammalian / Q000196:embryology*; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000166:cytology / Q000502:physiology*