pellucid zone

biology

Also known as: zona pellucida

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July 1, 2026

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The "pellucid zone" is more accurately referred to as the zona pellucida. This is a transparent, noncellular outer layer of a mammalian ovum, composed of glycoproteins. It plays a crucial role in fertilization by binding with sperm of the appropriate species and preventing polyspermy (the entry of more than one sperm). The zona pellucida is a thick coat surrounding the egg, which sperm must penetrate to reach the ovum.12

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animal development
Preparatory events
…is surrounded by the so-called pellucid zone, which is equivalent to the vitelline membrane of other animals; follicle cells form an area called the corona radiata around this zone.
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…is surrounded by the so-called pellucid zone, which is equivalent to the vitelline membrane of other animals; follicle cells form an area called the corona radiata around this zone.
Read More