Notably, by depleting H3K4 methylation specifically in the transcriptionally silent window before ZGA, we show that maintenance of H3K4 methylation patterning in pre-ZGA embryos is crucial for proper ZGA and expression of pluripotency factors.

Also, we found that H3K4me3 is mostly maintained from gametes to embryos, separated by a transcriptionally silent phase. Surprisingly, this maintenance was at promoters of genes that were transcribed in the gametes and are activated again during ZGA in the embryo.