Fig. 4

Examples of conservation and dynamics of the two histone modification markers, H3K4me3 and H3K27me3, exemplified by integrative genomics viewer (IGV) snapshots. a Groups I–IV histone modification patterns of H3K27me3 in the WTW → DTW → ETW process. For Group I (conserved), the three possible relationships, namely, A = B, A < B and A > B, in each of the WTW → DTW → ETW steps are presented; Group II shows changes that occurred in DTW and maintained in ETW; Group III shows changes that occurred in DTW and changed further in ETW; Group IV shows changes that only occurred in ETW. b Groups I–IV histone modification patterns of H3K4me3 in the TAA10 → ETW → XX329 ploidy transition process. For Pattern I (conserved), all three changing patterns, namely, A = B, A < B and A > B, in each of the TAA10 → ETW → XX329 steps are presented; Pattern II indicates reversible changes that are exclusively dependent on the presence of DD subgenome; Pattern III indicates changes that only occurred in XX329, reflecting prompt trans-subgenome regulation mediated by the presence of a novel DD genome (newly introduced from Aegilops tauchii); Pattern IV indicates changes that occurred in ETW and XX329, suggesting possible distinct functions of the AABB subgenome mediated by co-existence with the DD genome