Corona radiata

Definition

The corona radiata is a layer of cells that surround the egg (oocyte) in mammals, providing essential support and nutrients to the developing egg. This layer remains attached to the oocyte even after ovulation and must be penetrated by sperm for fertilization to occur.

Related terms

Zona pellucida: A thick, transparent coating surrounding the oocyte and corona radiata, acting as an additional barrier that sperm must penetrate to fertilize an egg.

Oocyte: An immature female reproductive cell or egg cell that develops into a mature ovum upon fertilization.

Fertilization:

The process by which a sperm cell successfully penetrates an oocyte's defenses (corona radiata and zona pellucida), allowing for the merging of male and female genetic material