Causality in transcription and genome folding: Insights from X inactivation

• Published in: BioEssays Vol. 44; no. 10; pp. e2200105 - n/a
• Main Authors: Bauer, Moritz, Payer, Bernhard, Filion, Guillaume J.
• Format: Journal Article
• Language: English
• Published: Cambridge Wiley Subscription Services, Inc 01.10.2022
• Subjects: chromatin; Chromosomes; Conformation; Deactivation; Folding; genome organization; Genomes; Inactivation; Transcription; X chromosomes; X‐inactivation; X‐reactivation
• ISSN: 0265-9247; 1521-1878
• DOI: 10.1002/bies.202200105

The spatial organization of genomes is becoming increasingly understood. In mammals, where it is most investigated, this organization ties in with transcription, so an important research objective is to understand whether gene activity is a cause or a consequence of genome folding in space. In this regard, the phenomena of X‐chromosome inactivation and reactivation open a unique window of investigation because of the singularities of the inactive X chromosome. Here we focus on the cause–consequence nexus between genome conformation and transcription and explain how recent results about the structural changes associated with inactivation and reactivation of the X chromosome shed light on this problem. The cause–consequence nexus between genome conformation and transcription is essential for our understanding of gene regulation. Uniquely addressed by the phenomena of X inactivation and reactivation in female mammals, where transcription and 3D structure change chromosome‐wide, we highlight how recent insights can help us understand gene regulation in 3D.