Fig. 5. Temporal requirement for kit in regeneration melanocyte development. Requirement for kit in development of melanocytes that develop first at stage 4 in regenerating wild-type fins. Melanocytes stem cells (MSC) are presumably established during embryonic development and persist through adult stages. After fin amputation (amp.), melanocyte stem cells are recruited to form melanoblasts (MB) by regeneration stage 2. Melanoblasts differentiate into melanocytes (MC) by stage 4, as evidenced by their expression of melanin (indicated by shaded area). Minimal stages of kit requirement are spanned by a black bar, with maximal possible stages of kit requirement spanned by error bars. Requirement for kit in the regeneration melanocyte lineage begins between regeneration stages 2 and 3 and extends beyond the onset of melanin synthesis at stage 4. kit is required for survival of stage 4 regeneration melanocytes until they acquire kit-independence between stages 7 and 11. Regeneration melanocytes which pigment later than stage 4 require kit for a similar duration of time before and after their differentiation (not shown). Note that kit is not required during embryonic or adult stages to promote the establishment or maintenance of melanocyte stem cells.
