Corona radiata (embryology)


 * For the structure in neuroanatomy, see Corona radiata.

The corona radiata surround an ovum or unfertilized egg cell, and consist of two or three strata (layers) of follicular cells. They are attached to the outer protective layer of the ovum, the zona pellucida, and their main purpose in many animals is to supply vital proteins to the cell. They appear at ovulation, but may disappear eventually after fertilization.