Fig. 3. Cyclin E overexpression results in nuclear loss. RNAs encoding cyclin E1 alone (A) or cyclin E1 with cdk2 (D), cyclin A2 alone (B) or cyclin A2 with cdk2 (E), cdk2 alone (C) or ß-gal as a control (F) were injected into one cell of a 2-cell embryo and allowed to develop to stage 8.5. Embryos were fixed, depigmented and the DNA stained with Hoechst. Animal caps were dissected and viewed by fluorescence microscopy. White arrows indicate regions in which nuclei are absent.