# Supplemental Data for Ali et al., 2021

**Figure
S1. Met inhibition alters the distance that dorsal OPCs migrate. **(A-F)
Quantifications taken from time-lapse movies of DMSO (n = 7) and MK2461-treated
(n = 7) larvae in (Figure 1C). Statistical test: Student’s t-test.

**Figure
S2.** ** met mutants exhibit a 16 bp insertion and
reduced dorsal OLCs. **(A) Bright-field images

*of met*

^{+/+}, met^{+/uva38}^{,}and

*met*

^{uva38/uva38}^{ }siblings at 3 dpf reveal no developmental delay in

*met*

^{uva38/uva38}^{ }larvae. (B) RT-PCR of mRNA transcripts extracted from 48 hpf

*met*

^{+/+},*met*, and

^{+/uva38}

^{metuva38/uva38}^{ }embryos demonstrating 16 bp insertion in

*met*and

^{+/uva38}*met*RNA transcripts. (C) Images of 72 hpf

^{uva38/uva38 }*olig2:egfp met*and

^{+/+}*met*larvae spinal cords. Yellow open arrowheads denote dorsal OLCs. Dashed yellow line denotes ventral edge of the spinal cord. (D) Quantifications taken from spinal cord images of

^{uva38/uva38 }*met*(n = 3),

^{+/+}*met*(n = 6),

^{+/uva38}*met*(n= 7), and

^{+/fh534}*met*(n = 6) larvae. Mean with SEM. Statistical test: 1-way ANOVA with Tukey’s Multiple Comparison Test. Scale bars, 0.5 mm (A), 20 μm (C).

^{uva38/fh534}

**Figure
S3.** ** met mutants do not exhibit defects in OPC
distance traveled or velocity. **(A-G) Quantifications taken from 18 hour
time-lapse movies of 55 hpf

*olig2:egfp met*(n = 8),

^{+/+}*met*

^{+/uva38}^{ }(n = 8), and

*met*

^{uva38/uva38}^{ }(n = 6) larvae in (4C). Statistical test: 1-way ANOVA with Tukey’s Multiple Comparison Test.

**Figure S4. hgfa mutants exhibit
reduced OPC numbers.** (A) Lateral (upper) and optical section
(lower) views of Sox10 antibody labeled 72 hpf wildtype,

*hgfa*and

^{+/+},*hgfa*

^{fh528/fh528}^{ }larvae. Horizontal yellow line denotes location of orthogonal view. Yellow dashed line denotes ventral edge of the spinal cord. Yellow open arrowheads denote sox10

^{+ }OLCs. Dashed yellow circle denotes boundary of spinal cord. (B-E) Quantifications taken from images of 72 hpf Sox10 antibody labeled

*hgfa*(n = 14),

^{+/+}*hgfa*

^{+/fh528}^{ }(n = 11), and

*hgfa*

^{fh528/fh528}^{ }(n = 14) larval spinal cords. Mean with SEM. Statistical test: 1-way ANOVA with Tukey’s Multiple Comparison Test. Scale bar, 10 μm.

**Figure
S5. met mutants exhibit wildtype OPC specification. **(A) Transverse
sections of 48 hpf

*olig2:egfp;sox10:mrfp; met*and

^{+/+}*met*

^{uva38/uva38}^{ }embryos. Open yellow arrowheads denote

*sox10*OPCs. Dashed yellow circle denotes boundary of spinal cord. (B-E) Quantifications of

^{+}/olig2^{+}*olig2*OPCs from serial sections of 48 hpf

^{+}/sox10^{+}*olig2:egfp;sox10:mrfp met*(n = 6) and

^{+/+}*met*(n = 4), and

^{+/uva38}*met*(n = 4) embryos. Mean with SEM. Statistical test: 1-way ANOVA with Tukey’s Multiple Comparison Test. Scale bar, 10 μm.

^{uva38/uva38 }

**Movie 1. New cell tracking software labels
migratory olig2^{+} cells in olig2:egfp larvae from 55 to
76 hpf.** Images were taken every 10 minutes and the movie runs at
10 frames per second (fps).

**Movie 2. DMSO-treated olig2:egfp larvae
exhibit wildtype OPC migration from 55 hpf to 76 hpf. **Images
were taken every 10 minutes and the movie runs at 10 fps.

**Movie 3. MK2461-treated olig2:egfp larvae
exhibit reduced dorsal OPC migration from 55 to 76 hpf. **Images
were taken every 10 minutes and the movie runs at 10 fps.

**Movie 4. olig2:egfp;met^{+/+}
larvae exhibit wildtype OPC migration from 55 to 76 hpf. **Images
were taken every 10 minutes and the movies runs at 10 fps.

**Movie 5. olig2:egfp;met^{uva38/uva38 }larvae
exhibit reduced dorsal OPC migration from 55 to 76 hpf. **Images
were taken every 10 minutes and the movie runs at 10 fps.