Fig. 6: CBP/P300 activity is exceptionally enhanced during ZGA.

A Developmental stages of medaka. B Representative Western blot of H3K27ac, H3K18ac, H3K9ac, and H4K16ac. Linearity was tested using titrated fibroblast samples. Same number of cells (1×) were loaded to lanes. C Quantification of (B). Each dot indicates the intensity of band. Two-sided unpaired Student’s t test. n = 4, 4, 4, and 5 biological replicates for H3K27ac, H3K18ac, H3K9ac and H4K16ac Western blot, respectively. Source data are provided as a Source Data file. D Schematics showing H3.3S31ph deposition and enhancement of CBP/P300 HAT activity. E Representative Western blot of H3.3S31ph. Linearity was tested using titrated late blastula samples. Same number of cells (1×) were loaded to lanes. F Quantification of (E). Each dot indicates the intensity of band. Two-sided Welch’s t test. n = 3 biological replicates. Source data are provided as a Source Data file. G Heatmap showing H3.3S31ph enrichment (ChIP-seq) around H3K27ac proximal peaks in normal medaka embryos. Average plot is shown in Supplementary Fig. 5N. H Schematic showing chek1 overexpression (top) and the results of Representative Western blot (bottom). I Quantification of (H). Each dot indicates the intensity of band. Two-sided unpaired Student’s t test and Two-sided Welch’s t test. n = 7 biological replicates. Source data are provided as a Source Data file. J Scatter plots indicate RNA-seq expression levels in no injection and Chk1-injected embryos. Red and blue dots indicate significantly upregulated and downregulated genes ( | log2 fold change | > 1, adjusted p value < 0.01, RPKM > 1.5) in Chk1-injected embryos, respectively. Pink, green, and light blue dots indicate Maternal, Maternal-ZGA, and Pure ZGA genes (see Supplementary Fig. 1F–H), respectively. n = 2 biological replicates. K Venn diagram indicates overlap of CBP/P300-dependent genes, CBP/P300-indepndent genes, and significantly upregulated genes in Chk1-injected embryos. L PCA analysis of RNA-seq data from normal development¹⁹, A485 treatment, and Chk1 injection. Each dot indicates one of the replicates. Dashed arrow indicates normal developmental process. No injection is located adjacent to pre-ZGA stage (late morula), while Chk1-injected is located closer to the post-ZGA stages (early blastula and late blastula). *: p < 0.05, **: p < 0.01, ***: p < 0.001, NS not significant. hpf hours post fertilization. Error bars indicate the mean ± s.d.