High rates of survival and fertilization of mouse and hamster oocytes after vitrification in dimethylsulphoxide.
A high proportion (> 70%) of mouse and hamster oocytes exposed for 3-5 min to 1.5 M dimethylsulfoxide (DMSO) and washed briefly in 3.9 M DMSO before vitrification in 6.0 M DMSO appeared morphologically normal on recovery. Significantly fewer (< 46%) mouse oocytes appeared normal when the time of exposure to 1.5 M DMSO was reduced to 1 min or less. The rate of fertilization in vitro of vitrified oocytes was reduced compared to the rate for untreated controls (mouse: 79% vs. 94%; hamster: 73% vs. 87%). After removal of the zona pellucida, fertilization was similar in vitrified and control hamster oocytes inseminated with hamster (> 90%) or human (21% vs. 23%) sperm. Sperm nuclear decondensation and pronuclear formation appeared to be delayed in the cytoplasm of vitrified hamster oocytes. Seventy-nine percent of 2-cell-stage mouse embryos derived from vitrified oocytes implanted after transfer to pseudopregnant recipients, but only 40% developed to normal fetuses compared to 61% of controls. The reason for this high rate of postimplantation loss is unknown.
MRC Experimental Embryology and Teratology Unit, St. George's Hospital Medical School, Tooting London, United Kingdom.
M J
MJ
Wood
C
C
Barros
C J
CJ
Candy
J
J
Carroll
J
J
Melendez
D G
DG
Whittingham
D000818:Animals; D001755:Blastocyst / Q000502:physiology; D002470:Cell Survival / Q000502:physiology*; D004121:Dimethyl Sulfoxide; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D014021:Tissue Preservation; D015044:Zona Pellucida / Q000502:physiology
D004121:Dimethyl Sulfoxide