Figure 4.

Effects of guanylic nucleotide starvation using mutants of the purine nucleotide biosynthesis pathway. A. Growth of an ade8Δ gua1Δ double mutant and an isogenic ade8Δ single mutant on SD medium containing the indicated purines. The SD + ADE + GUA medium contains 25% Adenine / 75% Guanine ratio (total purine concentration of 0.3 mM). B. The ade8Δ gua1Δ strains was grown in SD medium containing 25% Adenine / 75% Guanine ratio to OD_{600 nm} = 0.2; then shifted into the indicated medium. After 4 hours of incubation at 30°C, the percentage of cells with two daughters among budding cells was counted. More than 200 cells were counted for each condition. C. Growth of the WT strain, isogenic single amd1Δ or aah1Δ mutant strains and amd1Δ aah1Δ double mutant strain on SD medium, SD medium supplemented with adenine or SD medium supplemented with hypoxanthine. D. WT strain (left) and amd1Δ aah1Δ double mutant strain (right) were grown in SD medium to OD_{600 nm} = 0.2 and then shifted into the indicated medium. After 4 hours of incubation at 30°C, the percentage of cells with two daughters among budding cells was counted. More than 200 cells were counted for each condition.