Accepted_test

Keratin type II gene locus is a multigenic locus containing 26 genes and demonstrating strictly defined pattern of switching gene expression during epidermal differentiation. A complex chromatin locus requires a regulatory system, which we assume can be performed by locus control regions (LCRs) – superenhancers controlling gene expression of cell identity genes. We performed a comprehensive analysis using C-TALE, FISH in combination with confocal microscopy and ChIP-seq to reveal the structure of the keratin gene locus. We found a sequencial formation of contacts in the locus during epidermal differentiation, accompanied by its compaction. The cell treatment with various inhibitors of transcription and the formation of phase condensates revealed the presence of various mechanisms organizing the locus in mature keratinocytes.