Solubility properties of the murine zona pellucida

Abstract

The solubility properties of the zona pellucida surrounding the intact unfertilized murine egg were investigated. The structural integrity of the zona was shown to be disrupted by several disulfide bond reducing agents. A correlation was established between the rate of zonae dissolution in mercaptoethanol and the concentration of the sulfhydryl anion. It was possible to conclude, therefore, that disulfide bonds play a role in maintaining the structural integrity of the murine zona pellucida. The effect of pH on zonae solubility was reinvestigated. Removal of cumulus cells with unbuffered solutions of hyaluronidase or exposure of ova to low pH led to dramatic alterations in the physicochemical properties of the resultant zonae. This study provides the basis for evaluating possible relationships between the occurrence of a zona reaction and changes in the physicochemical properties of the zona pellucida.