In this experiment, we used RNAi targeting both copies of the gene polyhomeotic (ph-p and ph-d) to knockdown expression of this factor in Drosophila Kc167 cells. We observed substantial changes to the structure of genomic loci bound by Polycomb-group proteins as assayed by single-molecule based super-resolution imaging with STORM. We also observed a substantial de-repression of many genes which reside in Polycomb-bound domains, as assayed with RNA-seq. mRNA profiles from Drosophila Kc167 cells with and without knockdown the genes ph-p and ph-d were examined in duplicate.