DIMETHYLSULFOXIDE AFFECTS THE ORGANIZATION OF MICROFILAMENTS IN THE MOUSE OOCYTE

The effect of dimethylsulphoxide (DMSO) on microfilament organisation has been studied in the mouse oocyte after staining with (NBD)‐phallacidin. The cortical actin meshwork was disrupted by exposure of oocytes to 1.5 M DMSO at 37°C, and this disruption was associated with changes in the cell surface, especially microvilli length and distribution, as observed by scanning electron microscopy. The irregular distribution of actin filaments observed also appears to lead to an irregular expansion of the cell after DMSO removal. However, when exposure to DMSO was combined with cooling, the effects on the microfilament system were much reduced. The reversibility of DMSO action is considered and the potential implications of microfilament disruption on the viability and functions of the oocyte discussed. Copyright © 1990 Wiley‐Liss, Inc.