Cajal body

Cajal bodies (CBs), also coiled bodies, are spherical nuclear bodies of 0.3–1.0 μm in diameter found in the nucleus of proliferative cells like embryonic cells and tumor cells, or metabolically active cells like neurons. CBs are membrane-less organelles and largely consist of proteins and RNA. They were first reported by Santiago Ramón y Cajal in 1903, who called them nucleolar accessory bodies due to their association with the nucleoli in neuronal cells.^[1] They were rediscovered with the use of the electron microscope (EM) and named coiled bodies, according to their appearance as coiled threads on EM images, and later renamed after their discoverer.^[2] Research on CBs was accelerated after discovery and cloning of the marker protein p80/Coilin.^[3] CBs have been implicated in RNA-related metabolic processes such as the biogenesis, maturation and recycling of snRNPs, histone mRNA processing and telomere maintenance. CBs assemble RNA which is used by telomerase to add nucleotides to the ends of telomeres.^[4]