Fig. 7.

H4K20me3 enrichment is detected in pericentric heterochromatin of developing germ cells in spread preparations. a Nuclear spread preparations from E10.5 to E11.5 embryos and from E13.5 male and female gonads were stained for H4K20me3 (green). This modification is enriched at pericentric heterochromatin in PGCs throughout germ cell development when analysed. E10.5 and E11.5 germ cells were identified by OCT4 (red), and E13.5 germ cells with TRA98 (red). Three or more embryo trunks or gonads were pooled for the nuclear spread preparations and 20–30 PGC, and somatic nuclei were recorded. Representative germ cells are marked with yellow dashed circles. Scale bars represent 10 μm. b Quantification analysis of H4K20me3 levels in the whole nuclear area (N.A.) and pericentric heterochromatin regions (PHC) in the different embryonic stages examined. Overall, the levels of H4K20me3 are significantly reduced in PGC pericentric heterochromatin areas compared to those of the surrounding somatic cells. Asterisks (* or **) indicate significant differences