Fig. 7

a Changes in p300 recruitment in LETS hybrids. In the X. tropicalis genome there are new hybridization-induced peaks as well as peaks that disappeared after hybridization. In the X. laevis genome there are no changes. b Newly introduced peaks appear to be repressed by H3K9me3 in X. tropicalis embryos. c Bottom: a significant number of hybrid-specific peaks are associated with DNA transposon repeats (threshold p ≤ 10e-6, > 20 times fold enrichment compared to all X. tropicalis peaks and present at least in 10% of the peaks). Top: the bar plots show the frequency of occurrence of Motif:lcl|rnd-1_family-451_DNA, Motif:rnd-1_family-203 and Motif:lcl|rnd-1_family-189_DNA_PiggyBac repeats per megabase in the three (sub)genomes. Those repeats are X. tropicalis-specific, as they occur more often compared to X. laevis genomes. d Profiles of X. tropicalis embryos p300 and LETS hybrid p300 in X. tropicalis hybridization-induced peaks loci. New peaks overlap with DNA transposon repeats. e Newly introduced peaks found to be enriched in TF DNA binding sites (threshold p ≤ 10e-6, fivefold enrichment compared to all X. tropicalis peaks and present at least in 10% of the peaks). The TFs that can bind these motifs include Homeobox factors, C2H2 Zinc finger proteins (CTCF, ZNF232), PAX4, TERF, and T-box factors. The AATC motif, marked by an asterisk, is annotated in TRANSFAC as a GATA1 motif, but closely resembles a Paired Homeobox consensus motif. f DMRs in hybrid embryos. g DNA methylation profiles showing the DNA methylation instability in LETS hybrids