Loss of HP1 causes depletion of H3K27me3 from facultative heterochromatin and gain of H3K27me2 at constitutive heterochromatin

Phenotypic consequences of redistribution of H3K27me2/3 to constitutive heterochromatin. (A) The linear rate of growth was measured for sibling sets of wild-type, dim-5, set-7, and set-7; dim-5 strains. dim-5 strains (squares) show slow growth relative to wild-type (circles) and set-7 (triangles) strains, whereas strains defective in both set-7 and dim-5 (diamonds) show an intermediate rate of growth, suggesting that ectopic H3K27me2/3 is partly responsible for the poor growth of dim-5 strains. (B) Comparison of growth rates for wild-type, set-7, hpo, and set-7; hpo double-mutant strains. The slow growth phenotype of the hpo strain is partially relieved in the set-7; hpo double-mutant strain.