The influence of the cell cycle on structure and number of nucleoli in cultured human lymphocytes.
The nucleoli of lymphocytes undergo a typical sequence of structural changes after stimulation by phytohaemagglutinin. These changes are independent of the cell cycle. Neither the inhibition of DNA-synthesis (by adenosine and methotrexate), nor the elimination of postmitotic interphase nuclei (by a colchicine block of mitoses), nor the release from such blocks has a noticeable effect on nucleolar structure or on the sequence of nucleolar changes. The number of nucleoli per cell is clearly influenced by the cell cycle. Mitosis leads to a marked increase in the number of nucleoli, whereas in all stages of interphase a decrease occurs.
D002466:Cell Nucleolus / Q000648:ultrastructure*; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D006801:Humans; D007399:Interphase; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000166:cytology* / Q000648:ultrastructure; D008938:Mitosis; D010835:Phytohemagglutinins / Q000494:pharmacology; D011132:Polyribosomes / Q000648:ultrastructure
D010835:Phytohemagglutinins; D004247:DNA