Fig. 3. Transient requirement on kit for differentiated melanocyte survival. kitj1e99 mutant regenerating fin photographed at stage 7 following regeneration at 25°C (A), and immediately shifted to 33°C and later photographed at stage 13 (B). Note most regeneration melanocytes are lost by stage 13, with persistent melanocytes (black arrows in (B) and (E)) located only in the most proximal region of the regenerate (indicated by green bars in A,B,D,E). (C) Longitudinal section of a stage 10 kitj1e99 regenerate shifted to 33°C at stage 7 shows punctate distal melanocytes in the epidermis (white arrowheads), and proximal dermal dendritic melanocytes (black arrows). Basement membrane is indicated by an asterisk. (D,E) kitj1e99 mutant regenerating fin photographed at stage 11 following regeneration at 25°C (D), immediately shifted to 33°C at stage 11 and later photographed at stage 17 (E). Note that region of persistent melanocytes (green bars) has expanded distally. Amputation planes are indicated by black arrowheads, with distal to the right of figures. Scale bars: 200 µm (A,B,D,E), 20 µm (C).