931564.fig.002a
(a)
931564.fig.002b
(b)
Figure 2: Ultrastructure of mouse embryo nuclei in early 1-cell embryo (a) and in late 2-cell embryo (b). At the ultrastructural level, typical IGCs (arrows) are clearly revealed in transcriptional active 2-cell embryos (b) but not in 1-cell embryos (a). Nucleolar precursor body (NPB). Bar is 0.5 μm.