Chromosome Res. 2005;13(1):57-72 doi:10.1007/s10577-005-6845-6

Spada F, Vincent M, Thompson EM.

Plasticity of histone modifications across the invertebrate to vertebrate transition: histone H3 lysine 4 trimethylation in heterochromatin.

“Knobs” of heterochromatin, prominently visible in endocycling nuclei, are mildly enriched for H3K9me2 and H42K20me2 and 5mC, enriched for H3K4me4, highly enriched for H3K9me3 and depleted in H4K8Ac and H3K4me2 and elongating RNA Polymerase II. “Inhibition of polII transcription in NIH3T3 cells does not diminish global levels of H3 Me3K4 and results in increased H3 Me3K4 labelling in pericentromeric chromatin.”