Open AccessNew data concerning the functional organization of the mammalian cell nucleolus: detection of RNA and rRNA byin situmolecular immunocytochemistry
Author(s) -
Marc Thiry
Publication year - 1992
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/20.23.6195
Subject(s) - nucleolus , biology , rna , ribosomal rna , immunogold labelling , in situ hybridization , microbiology and biotechnology , immunocytochemistry , in situ , messenger rna , biochemistry , gene , genetics , cytoplasm , antibody , chemistry , endocrinology , organic chemistry
We have investigated the fine spatial distribution of RNA and rRNA within the Ehrlich tumor cell nucleolus by in situ hybridization with a biotin-labeled probe and by two new strategies, the polyadenylate nucleotidyl transferase-immunogold technique and immuno-labeling with anti-RNA antibodies. Besides the presence, as expected, of RNA and rRNA in the granular component and the dense fibrillar component, we show, for the first time, significant label over all the fibrillar centers of the nucleoli. When RNA and DNA were detected simultaneously on the same sections, only the fibrillar centers were positive for both. These results throw light on the controversial subject of the precise location of transcribing rRNA genes within the nucleolus. The fibrillar centers, and not the dense fibrillar component, should thus be the site of rRNA synthesis.