A glycoprotein membrane surrounding the plasma membrane of an oocyte. It is a vital constitutive part of the latter, external but not extraneous to it. The zona pellucida first appears in multilaminar primary oocytes.

http://upload.wikimedia.org/wikipedia/commons/8/81/Gray3.png

zona pellucida - vitelline membrane

uberon

zona radiata, vitelline envelope, vitelline membrane, pellucid zone, zona striata, oolemma, striated membrane

Outside the plasma membrane, three envelopes surround the ovum. The first, the primary egg envelope, lies between the plasma membrane and the surrounding cells of the ovary. The most consistent component of this primary layer is the vitelline membrane, a transparent jacket of fibrous protein. In mammals, the homologous structure is called the zona pellucida.[well established][VHOG]

UBERON:0000086

http://purl.obolibrary.org/obo/uberon.owl, http://purl.obolibrary.org/obo/cl.owl

• morula