Dynamic patterns of H4K20me2/3 during IVF and SCNT cleavage-stages embryo development.

<p><b>(A)</b> Representative images of porcine IVF and SCNT embryos at different developmental stages immunostained with an anti-H4K20me2 antibody. Antibody was localized with an Alexa Flour 488-conjugated secondary antibody (green). DNA was stained with propidium iodide (red). Middle panels showed the merged images (yellow) between H4K20me2 signal (green) and DNA staining (red). Red dash line marks the developmental stages with different H4K20me2 signal intensity between IVF and SCNT embryos. Arrow denotes H4K20me2 signal intensity was abnormally lower in SCNT embryos than that in IVF counterparts. <b>(B)</b> Representative images of porcine IVF and SCNT embryos at different developmental stages immunostained with an anti-H4K20me3 antibody. Arrow denotes H4K20me3 signal intensity was abnormally higher in SCNT embryos than that in IVF counterparts. White dash circle denotes ICM. Scale bar = 50 μm. <b>(C)</b> Quantification of H4K20me2 intensity between IVF and SCNT early embryos. (D) Quantification of H4K20me3 intensity between IVF and SCNT early embryos. Blue bars denote IVF group, red bars represent SCNT group. Values are mean ± S.E.M. Different letters (a-b) on the bars indicate a statistically significant difference between IVF and SCNT groups (<i>p</i> < 0.05).