Fig. 8. Arabidopsis Polycomb-group protein complexes. The core components of the Drosophila PRC2 complex are shown at top. In Arabidopsis, an equivalent ancestral complex is proposed to have diversified into three similar complexes with at least partially discrete functions. The colours indicate homology; so for example, E(z) homologues are coloured red. The contacts indicate interactions; for example, FIE can interact with MEA and MSI1 but not FIS2, whereas FIS2 can interact with MEA but not with other FIS proteins. The target genes shown are not comprehensive; it is likely that all three complexes have many more targets than those shown.