Fig. 6
From: Functional dissection of Drosophila melanogaster SUUR protein influence on H3K27me3 profile
Scheme explaining the effects of SUUR on H3K27me3 maintenance and under-replication in polytene chromosomes. a Possible mechanisms that were checked in this study that could affect H3K27me3 in SuUR mutants. b In wild type, SUUR contributes to chromatin maintenance in a way that replication forks are delayed to allow the H3K27me3-enriched chromatin context to be re-established. This would result in under-replication in the most extended SSRs and SNRs. PRCs also act in SNRs and produce H3K27 methylation. c In SuUR mutants, SUUR-dependent chromatin maintenance is inactivated, so the replication is more efficient while H3K27me3 is lost in SSRs. In SNRs, H3K27me3 level is reconstituted by the resident PRCs. Below the schematic pictures of polytene chromosomes are shown. Red dots—H3K27me3 histones