FIGURE 3.

Growth and G₁ arrest of wild-type and sit4Δ cells during nitrogen starvation or α-factor treatment. Wild-type (TB123) and sit4Δ (TB136–2a) were pregrown in either YNB-proline (A and B) or YNB-glutamine (C) medium. The cultures were then transferred to nitrogen-free medium (A and B) or treated with α-factor at a final concentration of 2 μgm/ml (C). Cell growth was determined by light scattering at A_{600 nm} (A). The number of budded and unbudded cells was determined by direct microscopic inspection of more than 200 cells/point (B and C). Values above the histograms are the percentages of unbudded cells for that point.