Showing papers on "Nucleolar chromatin published in 1973"
TL;DR: Using the toluidine blue-ammonium molybdate staining method, different types of RNPs were demonstrated in the hepatocytes of patients with kwashiorkor, andDCR-I and DCR-III were found to be reduced.
Abstract: Using the toluidine blue-ammonium molybdate staining method, different types of RNPs were demonstrated in the hepatocytes of patients with kwashiorkor. DCR-I and DCR-III were found to be reduced. Nucleolar chromatin and nucleolar parachromatin showed an apparent increase. Chromosomal, perichromosomal and nuclear parachromatin remained unaffected. Granular cytoplasmic RNP was nonreactive in all the cases.
01 Jan 1973
TL;DR: These observations suggest that the host E. coli RNA polymerase, the modified T4 polymerase and the new phage-specified polymerase recognize different nucleotide sequences and thus bind to and transcribe from different initial binding sites (promoter sites) on the phage DNA.
Abstract: Investigations of bacteriophage infection of Eschenichia coli have established a role for the DNA-dependent RNA polymerase in the regulation of gene expression. It is now generally accepted that host E. coli RNA polymerase transcribes at least a part of the phage genome (the ‘early’ regions) whereas a modified host RNA polymerase (in the case of T4) or even a new phage-specified polymerase (as in the case of T7) transcribes the ‘late’ regions (Travers, 1971; Bautz, 1972). These observations suggest that the host E. coli RNA polymerase, the modified T4 polymerase and the new phage-specified polymerase recognize different nucleotide sequences and thus bind to and transcribe from different initial binding sites (promoter sites) on the phage DNA. Thus at least one “positive” control mechanism resides in the ability of different polymerase species to recognize different promoter sites.
TL;DR: A group of prominent nucleoli, localized in a few sub-apical cells, was detected in young seedlings of rice shoot apex and the possible dependence of nucleolar orientation upon the nuclear rotation, as a consequence of deeply penetrating nucleolar chromatin, is admitted.
Abstract: SUMMARYAfter histological examination of young seedlings of rice shoot apex, a group of prominent nucleoli, localized in a few sub-apical cells, was detected. Three different staining techniques for cytochemical localization of nucleic acids, including enzymatic digestion, revealed a presence of small nucleolar bodies, which were pepsin resistant, and an amorphous susbstance, which was pepsin susceptible.The pair of nucleolar bodies adopted frequently either a parallel or perpendicular position with respect to the surface of shoot apex. The possible dependence of nucleolar orientation upon the nuclear rotation, as a consequence of deeply penetrating nucleolar chromatin, is admitted.The apparent resemblance with other examples of unusual nucleolar behaviour (in both plant and animal gametogenesis and in some cases of induced structural alterations) is discussed.