Promoter marking by modified histones before ZGA onset is associated with enhanced gene expression potential after ZGA. Graph shows the percentage of expressed genes (≥5 RNA-seq reads) at or after the MBT (post-ZGA) as a function of promoter DNA methylation state and marking by H3K4me3, H4K9me3 or H3K27me3 at the pre-MBT or MBT stages. **P < 10-5; *P < 0.001; -P = 0.058 (Chi-square test with Yate's correction).
Andersen et al. Genome Biology 2012 13:R65 doi:10.1186/gb-2012-13-7-r65