Nuclear bodies: new insights into assembly/dynamics and disease relevance.

Eukaryotic cells enclose their genome within a dedicated organelle, the nucleus, which is the site of major cellular events such as messenger RNA synthesis and processing, ribosome subunit biogenesis and DNA replication. Like the cytoplasm, the nucleus is compartmentalized to facilitate efficient coordination of these pathways, although subnuclear compartments form without the use of membranes. Numerous disease states have been linked to dysfunction of these compartments or 'nuclear bodies'. Recent advances have shed light on the formation and maintenance of key structures, including nucleoli, splicing speckles, paraspeckles, Cajal bodies, histone locus bodies and promyelocytic leukemia bodies. Here, we review the impact of these findings, which provide major insights into dynamic processes that affect both structure and function within the nucleus.