Fig. 6. Effects of mouse GV oocyte cytoplasmic lysates on somatic nuclei and cloned embryos. (A) Intensity of histone H3-K9 methylation in cumulus cell nuclei; Me-H3-K9 is shown in green and nuclear membranes are stained by lamin B in red. (b) Intact cumulus; (e) permeabilized cumulus without cytoplasmic lysates (control) and (h) permeabilized cumulus with cytoplasmic lysates. (B) Intact and cumulus cell nuclei treated with GV cytoplasmic lysates were transferred to enucleated MII oocytes, then the oocytes were activated and cultured to the blastocyst stage. ICSI-generated embryos were used as controls. The intensity of H3-K9 methylation of zygote and blastocyst stages is shown in fertilized embryos (b,h); in cloned embryos with intact cumulus cells (d,j); and in cloned embryos with cumulus cells treated with GV oocyte cytoplasmic lysate (f,l). Arrows indicate the nuclei at metaphase or anaphase/telophase stages with high levels of Me-H3-K9. Scale bars: 20 µm. (C) Quantification of methylated histone H3-K9 in pronuclear, two-cell and blastocyst stage embryos (ICM, inner cell mass; TE, trophectoderm). Each column represents the normalized mean value of these intensities per developmental stage, except for blastocysts, and distinguishes between ICM and TE. The data are presented as the mean±s.e.m.