Fig. 4: H2AK119ub1 remodelling by egg factors is altered by sperm pre-treatment with a H2A deubiquitylase.

A Schematic representation of sperm treatment with oocyte extract containing USP21. B Left, Western blot of H2AK119ub1, H3K4me3, H3K9me3, H3K27me3 and histone H4 on untreated sperm, USP21 extract treated sperm and control extract treated sperm. Right, signal ratio of H2AK119ub1 to H4 in untreated sperm, USP21 treated sperm, or oocyte extract treated sperm. *** p < 0.005, **** p < 0.001, two-sided ratio paired t test (n = 6 independent experiments). Median is shown. (USP1 versus untreated, p-value = 0.0007; Control versus untreated, p-value = 0.1519; USP21 versus control p-value = 0.0001). C DNA fragments generated by MNase digestion of Xenopus laevis untreated sperm, control extract treated sperm, USP21 extract treated sperm, egg extract treated sperm and somatic cell. Data representative of two independent experiments. D Western blot analysis of H2AK119ub1 and histone H4 on sperm after treatment with control- or USP21- oocyte extract without (left) or with (right) subsequent replication in egg extract. Data representative of two independent experiments. E Heatmap of H2AK119ub1 and H3K4me3 signal (log(ChIP/Input)) in sperm after treatment with control- or USP21- oocyte extract without or with subsequent replication in egg extract. H2AK119ub1 signal is also shown in blastula stage embryo. All genomic locations enriched for H2AK119ub1 (peaks) in replicated samples are represented. F–I DNAme and H2AK119ub1 signal (log(ChIP/Input)) on Xenopus laevis genome CpG island (F) and repeat element (H). Z-score of H2AK119ub1 enrichment on CpG island (G) and repeat element (I) in sperm, replicated sperm and replicated USP21 sperm. H2AK119ub1 signal is also shown in blastula stage embryo. *** p = 0.0001, two-sided permutation test. Numbers of H2AK119ub1 peak overlapping the genomic feature are indicated for each cell type.