Genes in &quot;open,&quot; but not in &quot;closed&quot; higher-order chromatin compartments have access to transcription and splicing complexes located in the ICD compartment. Chromatin domains that build the &quot;open&quot; chromatin compartment are organized in a way that allows the direct contact of genes and nascent RNA to transcription and splicing complexes, respectively, preformed in the ICD compartment.