Term Name:	vitelline membrane
Synonyms:	m. vitellina, yolk sac membrane, zona pellucida, zona pellucida - vitelline membrane
Definition:	A structure directly adjacent to the outer surface of the plasma membrane of an ovum. It is composed mostly of protein fibers, with protein receptors needed for sperm binding, binding to sperm plasma membrane receptors. The species-specificity between these receptors contributes to prevention of breeding between different species [Wikipedia]. A protective layer around the egg[FBbt].
Ontology:	Uberon Ontology [UBERON:0003125]