Changes in nuclear and polysomal polyadenylated RNA sequences during rat-liver regeneration

Nuclear and polysomal polyadenylated RNA popalations of normal and 16 hour regenerating rat liver have been compared by mRNA-cDNA hybridisations and by unique DNA saturation experiments. It was found that nuclear polyadenylated RNA hybridises to 6.8% of unique DNA in both normal and 16 hour regenerating rat liver. However, cross-hybridisation experiments using cDNA have shown that 10–15% by weight of nuclear polyadenylated RNA sequences are specific to 16 hour regenerating rat-liver. Since both unique DNA and cINA hybridisation have shown that normal and 16 hour regenerating rat-liver polysomal polyadenylated RNA populations are qualitatively very similar sequences specific to 16 hour regenerating rat-liver nuclear polyadenylated RNA are nucleus confined. Polysanal RNA sequences which were abundant in normal rat-liver have become less abundant in regenerating rat liver.