Fig. 6. Mosaic analysis of brk3. (A) DIC image illustrating sector boundaries of types A and B (see Fig. 4B). (B) Chlorophyll autofluorescence at same boundary shown in A. (A,B) A white plus sign indicates a wild-type guard-cell pair, which is flanked by a mutant subsidiary (black arrowhead in A); a black minus sign indicates a mutant guard-cell pair that is flanked by a wild-type subsidiary cell (white arrowhead in A). (C) DIC image of a glue impression showing junctions between brk3 and wild-type pavement cells; black arrows indicate areas where the lobes of wild-type cells appear to have grown over the tops of adjacent, unlobed mutant cells. Scale bars: A, 100 µm; C, 70 µm.