Intermediate
Technical
In the Industry Vocabulary Test
zona pellucida
Pronunciation: ZOH-nah peh-LOO-si-dah
The glycoprotein shell surrounding mammalian oocytes and early embryos.
Full Definition
The zona pellucida is a thick, transparent membrane composed of glycoproteins that surrounds the oocyte and early embryo until the blastocyst stage. In reproductive genetics, it serves as the target for assisted hatching procedures and must be carefully managed during embryo biopsy procedures. The zona pellucida plays crucial roles in fertilization, preventing polyspermy, and protecting the developing embryo during early cleavage divisions.
Usage
Usage note: Always italicized in scientific writing when referring to the specific structure.
In Context
- "The embryologist noted that the zona pellucida appeared unusually thick, requiring assisted hatching before transfer." — IVF laboratory report
- "Zona pellucida hardening post-fertilization prevents additional sperm penetration." — Reproductive biology textbook
Also known as
ZP
Don't confuse with
zona radiata
corona radiata