SEM of a stage 2, 3-cell embryo in vitro, (original magnification x1200). The outer surface of the zona pellucida (ZP) is textured and has numerous sperm and a few corona radiata cells (C) attached.
From: Makabe et al., 2001. Reproduced with permission of the Italian Journal of Anatomy and Embryology.
Keywords: corona radiata cell(s), zona pellucida
Source: The Virtual Human Embryo.