Fig. 18. SEM of the periphery of a stage 2, 5-cell embryo in vitro, (original magnification x1500). Abundant corona radiata cells (C) cover the zona pellucida (ZP). The cells have numerous small microplicae, folds and microvilli. The nucleus (arrow) of one of the blastomeres is shown.
(From: Makabe et al., 2001. Reproduced with permission of the Italian Journal of Anatomy and Embryology.)