a, z-projection of 1 representative 100–250-cell embryo of 10, bearing gwIs4 in wild type, mrg-1, cec-4 and mrg-1; cec-4 mutants. Strains used: GW1047, GW1048, GW1039 and GW1038. b, Single focal planes of representative 100–250-cell embryos bearing gwIs4 and EMR-1–mCherry in wild type, mrg-1, cec-4 and mrg-1; cec-4 mutants. Insets show enlarged single nucleus. Strains as in a. c, Quantification of gwIs4 reporter distribution in zone 1, as described in Fig. 1b, in 100–250-cell embryos of the indicated genotype. Strains as in a. Each sample was compared pairwise to wild type or cec-4 by χ2 test. **P < 0.01 and ***P < 0.001. P and n (number of foci scored) values are shown in Supplementary Table 1. d, Box plots comparing, the indicated genotypes and the circularity of the GFP-tagged gwIs4 reporter The median is shown as a thick line and box limits are 25th and 75th percentiles Strains as in a. Probability values from two-sided Wilcoxon rank-sum tests are indicated: *P < 0.05 and **P < 0.001. n (foci analysed) = 91 (WT), 92 (cec-4), 91 (mrg-1) and 97 (mrg-1; cec-4) from left to right of the indicated genotype. Exact P values are listed in Supplementary Table 2. e, Box plots and n as in d, but comparing the aspect ratio of the GFP-tagged gwIs4 reporter. f, Box plot as in d, comparing, in intestine or hypoderm of L1 of the indicated genotype, GFP–Laci fluorescence intensity deriving from the gwIs4 reporter. Strains used: GW1047, GW1038 and GW1090. Left, n (nuclei analysed) = 86, 94, 42 and 58 (from left to right of the indicated genotype and tissue). Right, n (nuclei analysed) = 99, 99, 53 and 58 (from left to right of the indicated genotype and tissue). Whole-intestine values were pooled in proportion to their relative abundance in the tissue. Two-sided Wilcoxon rank-sum tests; ***P < 0.001. Exact P values are listed in Supplementary Table 2. g, Scatter plot comparing, gene expression in wild-type (N2) L1 larvae (x axis) to enrichment for H3K4me3 and H3K27ac in wild type (y axis) in the three different classes of upregulated genes as identified and colour-coded in Fig. 3c. h, ChIP analysis in cec-4 L1 larvae either under mrg-1 or control RNAi for the enrichment of H3K27me3 over total H3 in the indicated regions. Two-tailed Student’s t-tests; ns, not significant. P values are listed in Supplementary Table 2. Dots represent three biological replicates. Source data