Lymphocyte cell-cycle analysis by flow cytometry. Evidence for a specific postmitotic phase before return to G0.
We studied the cell cycle of lectin-stimulated human lymphocytes, making use of a flow cytometer. The RNA and DNA content of large numbers of individual cells was determined by supravital staining with acridine orange. The present study confirmed previous observations by others of a progression from G0 through G1 and S phase to G2/mitosis during the first 3 d in culture. It was also found that on subsequent days stimulated cells, before their return to G0, remained stationary in a state in which they contained the G0 complement of DNA and approximately twice the G0 complement of RNA. Cell-cycle manipulation with vinblastine and 5-bromo-2-deoxyuridine (BUdR) revealed that previous passage through both S phase and mitosis was required for entry into this newly observed late phase. In addition, there was high correlation (r = 0.973, P less than 0.001) between the number of cells in the late phase and measured [3H]thymidine uptake. It therefore appears that, in this system, stimulated cells remain in a distinct cell-cycle phase for a number of hours before their return to the resting state.
D001973:Bromodeoxyuridine / Q000494:pharmacology; D002453:Cell Cycle; D003208:Concanavalin A / Q000494:pharmacology; D003584:Cytological Techniques; D004247:DNA / Q000378:metabolism; D006801:Humans; D007399:Interphase; D008214:Lymphocytes / Q000166:cytology* / Q000378:metabolism; D008938:Mitosis; D012313:RNA / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism; D014747:Vinblastine / Q000494:pharmacology
D003208:Concanavalin A; D014747:Vinblastine; D012313:RNA; D004247:DNA; D001973:Bromodeoxyuridine; D013936:Thymidine