MURINE OOCYTE CYTOSKELETAL CHANGES, FERTILIZATION AND EMBRYONIC-DEVELOPMENT FOLLOWING EXPOSURE TO A VITRIFICATION SOLUTION

Oocytes were exposed sequentially to a 6M dimethylsulphoxide solution (VSD) at either room temperature or on ice. Viability was assessed by in vitro fertilisation or fluorescent staining of the spindle and chro mosomes. Oocytes exposed to VSD were either fixed immediately or follo wing a 5 hour incubation at 37 degrees C. Rates of normality were sign ificantly improved following exposure to VSD on ice (100% compared wit h 92% at room temperature). Fertilisation was 76% following VSD exposu re at room temperature, and was 95% following VSD exposure on ice. In all groups, normality of the cytoskeleton was lower than fertilisation rates from the same cohort of oocytes. However, cytoskeletal normalit y improved following the 5 hour incubation period (untreated control 4 3% and 79%, VSD at room temperature 31% and 36%, and VSD on ice 34% an d 50% without and with incubation respectively). Cytoskeletal normalit y was found to be more indicative of fertilisation and development to blastocyst following a period of incubation.