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Nucleolus fibrillar centerNucleolusNucleus


The nucleolus fibrillar center (FC) is a sub-compartment of most metazoan nucleoli. The transcription of ribosomal RNA (rRNA) genes generates 2 structures that are found in all nucleoli: the dense fibrillar component (DFC) and the granular component (GC). The DFC contains newly synthesized preribosomal RNA and a collection of proteins; the GC is made up of nearly completed preribosomal particles destined for the cytoplasm. In most metazoans, but generally not in lower eukaryotes, a third component, the FC, can be seen. The FC is surrounded by the DFC. The zone of transcription from multiple copy rRNA genes is in the border region between these 2 structures.


Nucleoli fibrillar center


› Cellular component


fibrillar center [ GO:0001650 ]
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