Fig. 5. Ectopic margin associated with a mutant sector. (A) The margin formed on the proximal side of the sector. (B) Fluorescence micrograph of the ectopic margin. The midrib is toward the right of the figure and the normal margin toward the left. (C,D), Scanning electron micrographs of the ectopic margin and the neighboring mutant cells. The boxed region in C is shown magnified in D. The arrow indicates epidermal cells with a mutant phenotype on the distal side of the ectopic margin. Scale bars 50 µm (B), 100 µm (C,D).