Open AccessTranscription Fidelity and Structural Integrity of Isolated Nucleoli
Author(s) -
BEEBEE Trevor J. C.,
BUTTERWORTH Peter H. W.
Publication year - 1977
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1977.tb11673.x
Subject(s) - nucleolus , transcription (linguistics) , rna , rna polymerase i , ribosomal rna , biology , dna , microbiology and biotechnology , rna polymerase , rna polymerase ii , polymerase , biochemistry , gene expression , gene , promoter , nucleus , linguistics , philosophy
1. RNA was transcribed in vitro using isolated nucleoli, the endogenous form A RNA polymerase and mercurated UTP as one of the nucleoside triphosphate substrates. The products were isolated from endogenous nucleolar RNA sequences by chromatography on sulphydryl‐Sepharose and analysed by hybridisation in vast DNA excess. The results of competition‐hybridisation experiments suggested that a large proportion of the transcript was ribosomal RNA although some sequences had been transcribed from DNA of lower reiteration frequency. 2. Analyses of the constituents of nucleoli following isolation by the sonication procedure suggested that the nucleolar DNA, particularly the ribosomal cistrons, are severely degraded. Furthermore, indications were obtained that the transcription complexes were damaged and many of the nascent RNA chains appeared to have been sheared from near the growing points.