<HashMap><database>GEO</database><file_versions><headers><Content-Type>application/xml</Content-Type></headers><body><files><Other>ftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE295nnn/GSE295407/</Other></files><type>primary</type></body><statusCode>OK</statusCode><statusCodeValue>200</statusCodeValue></file_versions><scores/><additional><omics_type>Other</omics_type><species>Mus musculus</species><gds_type>Other</gds_type><full_dataset_link>https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE295407</full_dataset_link><repository>GEO</repository><entry_type>GSE</entry_type></additional><is_claimable>false</is_claimable><name>Polycomb Chromatin Topology Enables Long-Range Enhancer Recruitment during Craniofacial Development [Hi-C]</name><description>Little is known about how three-dimensional chromatin topology shapes mammalian craniofacial development. In mouse cranial neural crest cells, a Polycomb Repressive Complex 2 (PRC2)-dependent chromatin architecture is established before migration. This configuration maintains craniofacial gene promoters poised and connects them with distal Polycomb tethering elements, positioning promoters in spatial proximity to future long-range enhancers. Deletion of Ezh2 disrupts this early topology, causing inappropriate gene derepression in post-migratory craniofacial subpopulations where these genes are normally silenced, and failure of long-range enhancer recruitment where activation is required, thereby impairing proper gene expression. We further identify a distal Polycomb tethering element essential for Hoxa2 enhancer recruitment across topologically associating domains. Thus, Polycomb acts not only as a transcriptional repressor, but also as a chromatin-folding organizer that prepares developmental genes for later activation, by facilitating subsequent recruitment of distal active enhancers previously not in contact. Polycomb-mediated topology therefore orchestrates the transition from progenitor plasticity to precise spatiotemporal control of morphogenetic gene programs during neural crest development and face formation.</description><dates><publication>2026/04/08</publication></dates><accession>GSE295407</accession><cross_references><GSM>GSM8947482</GSM><GSM>GSM8947483</GSM><GSM>GSM8947484</GSM><GSM>GSM8947485</GSM><GSM>GSM8947486</GSM><GSM>GSM9561923</GSM><GSM>GSM8947487</GSM><GSM>GSM8947488</GSM><GPL>19057</GPL><GSE>295407</GSE><taxon>Mus musculus</taxon></cross_references></HashMap>