Fig. 8. Mosaic analysis of brk1. (A) DIC image of an epidermal peel illustrating a type D lateral sector boundary (Fig. 4B), which overlies brk1 mesophyll. Scale bar: 110 µm. (B) Chlorophyll autofluorescence in same field of view shown in A. (A,B) A white plus sign indicates a wild-type stoma; black minus signs indicate brk1 mutant stomata in files with lobed pavement cells. Arrows (A) indicate mutant pavement cells with weak marginal lobes that are separated from wild-type cells by one file of mutant cells. (C) DIC image of an epidermal peel illustrating a type B transverse sector boundary (see Fig. 4B). (D) Chlorophyll autofluorescence in same field as shown in C. Epidermal cells with a brk1 mutation appear mutant where they overlie brk1 mesophyll (left of black arrowhead) but wild type where they directly overlie wild-type mesophyll (right of white arrowhead).