Maintenance of the meiotic spindle during vitrification in human and mouse oocytes

Abstract

Vitrification appears to be a viable method for the cryopreservation of human metaphase II (MII) oocytes, but concerns regarding the concentration of cryoprotectants used during vitrification have been raised. In an attempt to circumvent this potential problem, the majority of protocols are carried out at room temperature. Exposing oocytes to temperatures below 37 degrees C, however, leads to rapid microtubule depolymerization. Polarized light microscopy was used to measure meiotic spindle retardance following exposure to cryoprotectants and vitrification in human and mouse oocytes. To quantify the extent of depolymerization, spindle retardance was determined before and after each treatment...