Cajal body

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Cajal bodies (CBs) are spherical sub-organelles found in the nucleus of proliferative cells like tumor cells, or metabolically active cells like neurons. 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] Electron microscopists gave them the name "coiled body" because of their shape in EM sections. More recently, in honor of Ramón, they were termed Cajal bodies (CBs).[1]

They are about 0.1 - 2.0 micrometres and are found one to five per nucleus; the number varies over the cell cycle and in different types of cells. Cajal bodies are possibly sites of assembly or modification of the transcription machinery of the nucleus.[2]

Cajal bodies are only found in nuclei of plant, yeast, and animal cells. The cells are usually demonstrating high levels of transcriptional activity, including cells that are rapidly dividing.[1]

CBs are bound to the nucleolus by coilin proteins.

[edit] References

  1. ^ a b c Ogg S, Lamond A (2002). "Cajal bodies and coilin--moving towards function". J Cell Biol 159 (1): 17-21. doi:10.1083/jcb.200206111. PMID 12379800. 
  2. ^ Cremer T, Cremer C (2001). "Chromosome territories, nuclear architecture and gene regulation in mammalian cells". Nat Rev Genet 2 (4): 292-301. doi:10.1038/35066075. PMID 11283701.