Figure 5.

Dominant-negative and dosage effects of SLC45A2(W74R) expression in melanocyte-specific transgenic zebrafish. (a) Schematic view of SLC45A2 or SLC45A2(W74R) expression vector under control of the melanocyte-specific ftyrp1 gene promoter. ZsGreen1 is used as a fluorescent reporter for the transgene-positive cells (arrowheads). (b, f) Rescue effects of human SLC45A2 in slc45a2 KO zebrafish at 48 hpf. ZsGreen1-positive melanocytes are detected in homozygous slc45a2 KO (KO homo, −/−, n = 6). (c, g) No rescue effect of SLC45A2(W74R) in ZsGreen1-positive cells in KO homo (n = 6). (d, h, d′, h′) No effect of SLC45A2(W74R) in wild-type zebrafish (WT, +/+). ZsGreen1 is expressed in normal melanocytes in WT (n = 4). (e, i, e′, i′) Dominant-negative effects of SLC45A2(W74R) in heterozygous slc45a2 KO (KO hetero, +/−). ZsGreen1-positive melanocytes are not detected in KO hetero (n = 6). (b–e, d′, e′) Fluorescent images. (f–i, h′, i′) Bright-field images. (d′, e′, h′, i′) Magnifications of arrow-marked cells in d, e, h, and i, respectively. Scale bar: 100 µm.