Summary
ABSTRACT Heterochromatin, a gene-repressive nuclear ultrastructure, is required for the normal patterning of the genome into active and inactive regions, to preserve structural integrity and drive and maintain developmental fates. While heterochromatin assembly is locally nucleated by DNA-sequences, the majority of the patterning process requires it to spread along the chromatin template. A major form of heterochromatin involved in this patterning is signaled by methylation (me) at Lysine 9 (K9) of histone 3 (H3). Major questions have remained unanswered about heterochromatin spreading, which
