Fig. 1

Lineage-specific requirement for Aldh2 in melanocyte regeneration. (A) UMAP of scRNA-seq data derived from 24 hpf embryos (Brombin et al., 2022) with McSCs in red. Feature plots of these isolated McSCs showing log₂ expression of aldh2 paralogs with colour change from grey (negative) to purple. (B) Schematic of the melanocyte lineages in zebrafish development with confocal z-stacks depicting McSCs expressing mitfa:GFP located at the dorsal root ganglia (DRG) and melanoblasts (Mb) on the motor neurons. Neural tube and DRG are marked by nbt:dsRed expression. (C) Representative images of wild-type embryos treated with or without CVT-10216 during development (embryonic melanocytes) or in an McSC regeneration assay. Regenerated melanocytes were quantified within a consistent region delineated by the magenta dotted line on the non-regenerating control embryo (top). One data point plotted per embryo; boxes indicate median and quartiles; whiskers span minimum to maximum values. Scale bar: 500 µm. ****P<0.0001 (one-way ANOVA with Tukey's multiple comparisons test). Four experimental replicates. (D) Schematic of CRISPR-Cas9 strategy to target aldh2.1 and aldh2.2 with excision site between Cas9 cut sites (scissor symbols; see Fig. S1). Wild-type or aldh2^−/− embryos in normal development or a McSC regeneration assay is shown. ****P<0.0001. An unpaired two-tailed t-test was performed to calculate statistical significance. One data point is plotted per embryo; boxes indicate median and quartiles; whiskers span minimum to maximum values; three experimental replicates.