Figure 12.

Comparison of nuclear phenotypes from bovine fetal fibroblasts and cloned preimplantation embryos studied with 3D structured illumination microscopy. Panels A1–A8. Midplane SIM x/y-sections (left) and y/z-sections (right) from DAPI-stained fetal fibroblast nuclei indicate their common flat-ellipsoidal shape. DAPI-stained sections are shown together with immunostaining of nucleophosmin B23 (red) and of H3K4me3 (green) in A1, A3, A5 and A7. Corresponding sections with DAPI staining alone are presented in A2, A4, A6 and A8. Panels B1–B8. Midplane SIM x/y-sections (left) and y/z-sections (right) from DAPI-stained nuclei in a cloned 8-cell embryo demonstrate the transformation of the flat-ellipsoidal shape of fibroblast nuclei into a roundish shape with a more pronounced clustering of chromatin and the formation of a major lacuna, marked by asterisks (compare Figure 7, Panels J-Q). Panels C1–C4 and D1–D4. Four nuclei recorded by 3D-SIM from a cloned, non-hatched blastocyst (C1–C4) and 4 nuclei from a cloned, hatched blastocyst (D1–D4). These nuclei were present in cells, which maintained their connection during microdissection of the embryos for 3D-SIM (see Results and Extended Experimental Procedures) and likely represent trophectoderm nuclei. Bar: 4 μm in A1 representative for all Panels.