Cover photograph (Copyright © 2000, American Society for Microbiology. All rights reserved.): p21-activated kinase homolog Ste20p is important for bipolar bud site selection in yeast. Cells were stained with a fluorescent dye, Calcofluor, to reveal all the division sites (bud scars) on the mother cells. Cells in the upper half of this figure show the proximal budding pattern of ste20/ste20 cells. In this mutant, bud scars are clustered next to the birth site for cells that have undergone several rounds of budding. Cells in the bottom half of this figure are wild type. These cells display a bipolar budding pattern with bud scars at both proximal and distal poles. (See related article in the second July issue.)