Zona pellucida

(Latin, zona pellucida = transparent zone) A specialized extracellular matrix surrounds the developing ][O.htm#oocyte|oocyte]] (egg, ovum) within the ovary and follwing [O.htm#ovulation ovulation]. It consists of three types of glycoproteins [#ZP1 ZP1], [#ZP2 ZP2] and [#ZP3 ZP3] which have different roles in fertilization. Following fertilization, the zona pellucida also surrounds the blastocyst during the first week of development, from which it "hatches". The zona pellucida has a role in [F.htm#fertilization fertilization], sperm binding, preventing [P.htm#polyspermy polyspermy], [B.htm#blastocyst blastocyst] development and preventing premature implantation (ectopic pregnancy).

'UNSW Embryology Links: Week 1 - Fertilization | Week 1 - Oogenesis | [#zona_pellucida_binding_protein_1 zona pellucida binding protein]