Nucleolar Structure and Function in Trypanosomatid Protozoa.

摘要: The nucleolus is the conspicuous nuclear body where ribosomal RNA genes are transcribed by polymerase I, pre-ribosomal processed, and subunits assembled. Other important functions have been attributed to over years. Here we review current knowledge about structure function of in trypanosomatid parasites Trypanosoma brucei, cruzi Leishmania ssp., which represent one earliest branching lineages among eukaryotes. These protozoan present a single that preserved throughout closed division, seems lack fibrillar centers. Trypanosomatids possess relatively low number rRNA genes, encode molecules contain large expansion segments, including several trypanosomatid-specific. Notably, subunit (28S-type) fragmented into two four small species. Hence, compared other organisms, primary transcript requires additional processing steps trypanosomatids. Accordingly, this group contains highest ever reported snoRNAs participate processing. modified nucleotides trypanosomatids also higher than organisms. Regarding biogenesis ribosomes, recent cryo-electron microscopy analyses revealed trypanosomatid-specific features discussed here. Additional reviewed.