title: Optimal concentration of calcium and electric field levels improve tetraploid embryo production by electrofusion in mice.
abstract: Polyploid embryo production is an important technique in generating mice directly from embryonic stem (ES) cells. The present study was designed to assess the effect of different calcium concentrations and electric field intensities on the production of tetraploid embryos with higher developmental potential by electrofusion. Two-cell mouse embryos were electrofused in fusion solution containing different concentrations of calcium ion (0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2 and 1.4 mM). The rates of blastomere fusion, and subsequent cleavage and development of tetraploids to the blastocyst stage were highest when two-cell embryos were electrically stimulated in a fusion medium containing 1.0 mM calcium. Therefore, we tested electric field intensities (0.6, 0.8, 1.0, 1.2 and 1.4 kV/cm) for electrofusion of two-cell embryos and subsequent development to the blastocyst stage in 1.0 mM calcium. The highest rates of fusion and blastocyst formation were observed when the electric field strength was 0.8 kV/cm. The present results showed that mouse two-cell embryos stimulated with 0.8 kV/cm in a fusion medium containing 1.0 mM calcium had the highest rates of fusion and development to the blastocyst stage.
authors.affiliation: Laboratory of Animal Embryonic Biotechnology, College of Animal Science and Technology, China Agricultural University, Beijing, China.
authors.forename: Lun
authors.initials: L
authors.lastname: Suo
authors.forename: Fen
authors.initials: F
authors.lastname: Wang
authors.forename: Guang-Bin
authors.initials: GB
authors.lastname: Zhou
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Shi
authors.forename: Yong-Bin
authors.initials: YB
authors.lastname: Wang
authors.forename: Shen-Ming
authors.initials: SM
authors.lastname: Zeng
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Tian
authors.forename: Shi-En
authors.initials: SE
authors.lastname: Zhu
authors.forename: Guo-Shi
authors.initials: GS
authors.lastname: Liu
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002459:Cell Fusion; D002875:Chromosomes / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D004574:Electromagnetic Fields; D046149:Embryo Culture Techniques / Q000379:methods*; D053595:Embryonic Stem Cells / Q000166:cytology*; D005260:Female; D007477:Ions; D051379:Mice; D011123:Polyploidy
chemical_list: D007477:Ions; D002118:Calcium