[Comparative study of nuclear RNA of the liver and experimental hepatoma by the method of DNA-RNA molecular hybridization].

DNA

RNA molecular hybridization of rat liver and hepatoma nyclear RNAs was carried out under controlled conditions as to nucleotide composition and quantitative ratios of competing RNAs and the time of labelling. These factors are shown to influence the results of competition hybridization experiments. For instance a lower competitive ability of rat liver nuclear RNA as compared to that of hepatoma nuclear RNA stems to certain from a relatively higher GC-content of the former. However differences in the competitive efficiency of nuclear RNAs studied could be revealed even with preparations of equal nucleotide composition, these differences being but of quantitative character. The results of the experiments suggest that hepatoma nuclear RNAs are relatively rich in the fast-hybridizable fraction which does not differ qualitatively from the corresponding fraction is characterized by a high metabolic activity and certain tissue specifity.