Nuclear bodies is a collective term for a number of non-membrane bound nuclear sub-compartments. Common examples include Cajal bodies (CBs), Gemini of Cajal bodies (gems), promyelocytic leukemia (PML) bodies, histone locus bodies, Sam68 bodies and PcG bodies. Nuclear bodies consist of certain protein factors and often specific RNA molecules, concentrated together in defined regions. The assembly of nuclear bodies is generally driven by liquid phase separation and they display a constant dynamic exchange of factors with the surrounding nucleoplasm. Some nuclear bodies have a uniform inner structure, while others have a more intricate suborganization. The functions of nuclear bodies extend from RNA processing and RNP assembly, to DNA repair and stress responses, to subnuclear sequestration of various regulatory factors.
Nuclear bodies are visible as distinct membraneless spots in the nucleoplasm. They vary in shape, size and numbers depending on the type of nuclear bodies as well as cell type.
Read more about the proteome of nuclear bodies as a substructure of the nucleoplasm.