COMPARISON OF NUCLEAR RNAs FROM RAT LIVER AND RAT HEPATOMA CELLS BY DNA-RNA HYBRIDIZATION IN VAST DNA EXCESS
SUN JIN AND ZHANG YU-YAN (Shanghei Institute of Cell Biology,Academia Sinica)
The nuclear RNAs including thetotal nuclear RNA,nuclear poly (A)~+RNA and nuclear poly (A)~- RNAfrom rat liver and rat hepatoma cellswere compared by RNA-DNA hy-bridization in vast excess of DNAof rat liver.The results shown in theTable indicated that,in comparisonwith those of normal liver cells,RNApopulation 1 from total nuclear RNAwas decreased by 21% in repetitivefrequency (F) and increased by 95%in complexity respectively in hepa-toma cells;the frequency and complexity of RNA population 2 of totalnuclear RNA were both decreased by29% and 14% respectively in hepatoma cells;and the frequency and com-plexity of RNA population 3 of totalnuclear RNA were both increased by29% and 16% respectively in hepatoma cells. The frequency of poly (A)~- nRNAof rat hepatoma cells was increasedby 10% and 80% in RNA population1 and 3 respectively,and decreased by64% in population 2,as comparedwith those of rat liver cells.The com-plexity of poly (A)~- nRNA from rathepatoma cells was increased by 60 % ??in RNA population 1 and 2 respecti-vely,than those in rat liver cells.Si-milarly,the population 2 of poly (A)~+nRNA was decreased by 50% in frequency and increased by 60% in complexity in hepatoma cells than thosein rat liver cells.However,no significant difference was found between thefrequency and complexity of popula-tion 3 of poly (A)~+ nRNA from normal liver and hepatoma cells.