(C) Cells were grown to mid-log phase either in rich medium or starved for 8 hours. Zygotes and tetrads, which correspond to differentiated cells, were counted under a light microscope. Each value represents the mean percentage and SE of differentiating cells to the total number of cells, averaged from 4 independent experiments. At least 200 cells from the indicated genotypes were counted in each experiment. White arrowheads indicate zygotes. Scale bar, 10 μm. 