The daughter cell-specific budding pattern phenotype of pmt4 mutants may be explained by reduced activity of Axl2/Bud10p in both mother and daughter cells. (A) WT cells. 1, Axl2/Bud10p (black crescent) is localized at the periphery of a WT bud. 2, Axl2/ Bud10p is reorganized to the bud side of the mother-bud neck. 3, New synthesis of Axl2/ Bud10p leads to its accumulation on the mother side of the mother-bud neck. 4, After cytokinesis, both mother and daughter cells inherit a patch of Axl2/Bud10p. The mother cell initiates bud formation adjacent to the residual patch of Axl2/ Bud10p. 5, The daughter cell initiates bud formation adjacent to the residual patch of Axl2/ Bud10p. The residual patches of Axl2/Bud10p disappear (hatched rectangles). (B) pmt4 cells: 1, Axl2/Bud10p (black crescent) is localized at the periphery of a pmt4 mutant bud. Axl2/Bud10p is also found in punctate intracellular patches (black circles). 2, Axl2/Bud10p is reorganized to the bud side of the mother-bud neck. The reduced accumulation of Axl2/Bud10p to the bud neck is represented by the small size of the black rectangle (compare to A 2). 3, New synthesis of Axl2/Bud10p leads to its accumulation on the mother side of the mother-bud neck. The unstable Axl2/Bud10p disappears from the bud side of the mother-bud neck. 4, After cytokinesis, only mother cells inherit a patch of Axl2/Bud10p. The mother cell initiates bud formation adjacent to the residual patch of Axl2/Bud10p. 5, The daughter cell initiates bud formation using bipolar information, since it lacks a residual patch of Axl2/Bud10p. The residual patch of Axl2/Bud10p disappears from the mother cell (hatched rectangles).