Getting the genome in shape: the formation of loops, domains and compartments

Britta AM Bouwman, Wouter de Laat

The three-dimensional folding of the genome has emerged as an important regulatory layer of transcription and is regarded as being pivotal for the establishment and faithful maintenance of cellular identity. The hierarchical levels of genome compaction and folding exert transcriptional control by tuning the accessibility and proximity of genes and cognate regulatory elements. Despite the identification of many factors involved in genome topology, the mechanisms that underlie the establishment of three-dimensional genome architecture and its inheritance through successive cell divisions have remained largely unknown. Here, we review current insights into the chromatin components and associated trans-acting factors that enable the genome to flexibly adopt different functionally relevant conformations.