DETECTION OF RIBOSOMAL-RNA DURING THE CELL-CYCLE IN EHRLICH TUMOR-CELLS BY ELECTRON-MICROSCOPE IN-SITU HYBRIDIZATION

The fine spatial distribution of rRNA within Ehrlich tumour cells has been investigated during the cell cycle by in situ hybridization with a biotinylated probe. In interphase cells, rRNA was essentially detect ed in the ribosome-rich cytoplasmic regions and in the three main nucl eolar components. In mitotic cells, besides the presence, as expected, of rRNA in the ribosome-rich spaces, evident label was observed over material situated around and between the chromosomes during anaphase a nd telophase as well as over the reforming nucleoli during telophase.