Properties of the Membranes of Rat and Rabbit Eggs

Abstract

The properties of the membranes of rat and rabbit eggs-the zona pellucida, cumulus oophorus, and in the rabbit, the so-called "albumen" layerhave been studied. By histochemical techniques, it has been shown that all the membranes contain a large proportion of polysaccharide. The zonas are shown to be neutral or weakly acidic mucoproteins, being less acidic than the matrix of the cumulus oophorus, which is composed of hyaluronic acid and protein. Protein is demonstrable histochemically only in the zonas, but ready dissolution of the "albumen" layer and the matrix of the cumulus by pure proteinases indicates that protein forms an integral part of the structure of these layers. The term "albumen" is inappropriate, as the layer so designated has the properties of a strongly acidic mucoprotein.