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Figure 4
(A) Brightfield images of the melanocyte stripe before melanocyte ablation and after melanocyte regeneration in wild-type, kita(lf), and kitlga(lf) zebrafish strains. Scale bar = 200 µm. (B) Quantification of melanocyte regeneration in wild-type, kita(lf), and kitlga(lf) strains. Mean percentage ± standard error of the mean (SEM) is shown; WT n = 10, kita(lf) = 9, kitlga(lf) = 11 fish. p values calculated by one-way analysis of variance (ANOVA) with Dunnett’s multiple comparisons test, *p < 0.05, **p < 0.01. (C) Cellular trajectories, using Monocle3, of mitfa+aox5lo cells from wild-type zebrafish (left) and kita(lf) mutants (right). Solid lines represent trajectories, with an origin in the melanocyte progenitor-0 (MP-0) subpopulation and terminus in the melanocyte subpopulation. (D) Comparison of proportion of WT and kita(lf) cells per scRNAseq sample in the cycling differentiation and direct differentiation subpopulations during regeneration reveals fewer kita(lf) cells going through differentiation (WT Day 2 = 4510, WT Day 3 = 5224, WT Day 5 = 3483, kita(lf) Day 2 = 4233, kita(lf) Day 3 = 5261, kita(lf) Day 5 = 5411 total cells per sample). p values calculated using differential proportion analysis (Farbehi et al., 2019), ****p < 0.0001; ns, not significant. (E) Fates of progenitors following single-cell serial imaging of wild-type, kita(lf), and kitlga(lf) strains. Mean percentage of traced progenitors in a fate are shown; wild-type n = 4 animals (n = 49, 59, 53, 53 cells per animal), kita(lf) = 4 animals (n = 50, 50, 53, 28 cells per animal), kitlga(lf) = 4 animals (n = 52, 39, 53, 33 cells per animal). p values calculated by one-way ANOVA with Dunnett’s multiple comparisons test, ****p < 0.0001, *p < 0.05, ns, not significant.
kita receptor and kitlga ligand loss-of-function mutants have impaired melanocyte regeneration.