Fig. 4

Effect of HIV-1 Rev protein production on fission yeast. a Expression of HIV-1 rev delays cellular growth of S. pombe. S. pombe cells containing pYZ1N-rev was grown under gene-repressing (+T) and gene-inducing (−T) conditions in liquid minimal selection EMM at 30°C. The cell density was measured over time and growth curves were plotted. S. pombe cell containing pYZ1N was used as a control. The experiment was repeated three times and the standard errors of each time point were calculated. b Rev delays colony formation in fission yeast cells. A semi-quantitative colony dot dilution assay was use to evaluate the ability of individual rev-expressing S. pombe cells to form colonies on agar plates. The pYZ1N-rev transformed S. pombe cells were grown in liquid EMM medium to log phase with thiamine. Thiamine was then removed from cells by washing and equal number of cells transferred to EMM supplemented plates with (gene-off, left plate) and without (gene-on, right plate) thiamine. The plates were incubated at 30°C for 5 days. Each colony on a plate from left to right (1–6) represents cells plated from approximately 1,000 to 3 cells following threefold dilutions. The pYZ1N plasmid was used as a control. c Rev does not affect cell cycle of fission yeast. Cell cycle profiles were measured in the pYZ1N-rev and pYZ1N control S. pombe cells by flow cytometric analysis. The data show analyses after 24 and 67 h of cell culture in EMM selective media with (gene-off) and without (gene-on) thiamine. The cell cycle stages were monitored after staining with propidium iodide. The up-right numbers are the percentage of cells in G1, S and G2 phases of the cell cycle.