Lamprey neural crest migration is Snail-dependent and does not involve modulation of cadherin expression: Supplementary Data

Joshua R. York, Tian Yuan, Kevin Zehnder and David W. McCauley

Supplementary Figure S1. cDNA sequences of lamprey cadherins (CadIA, CadIIA) and NCAM used to generate RNA probes.

Supplementary Figure S2. Sequences from individual lamprey embryos showing mutations at the Snail locus after phenotypic analysis by in situ hybridization (ISH) and immunohistochemistry (IHC). Six or seven putative Snail CRISPR mutants from each gene expression analysis category in Fig. 5 (CadIIA, T22; SoxE2, T22; CadIIA, T26; Hu, T26; SoxE1, T26; Caspase3, T22) were randomly sampled after ISH or IHC for isolation and sequencing of genomic DNA to estimate efficiency of CRISPR-induced mutagenesis (see “Materials and Methods”). Note that every individual embryo sampled contains a mutation within the CRISPR target site (blue = gRNA sequence; red = PAM site). Numbers to the right of each sequence

indicate the number of base pairs deleted. Embryos that are represented with images in Fig. 5 are indicated to the left with their corresponding panel IDs.

Supplementary Figure S3. Effects of CRISPR-induced Snail mutations on Snail mRNA production. In wildtype embryos, Snail is expressed early in premigratory neural crest (A, black arrowhead), and somatic mesoderm (asterisks). During later stages, Snail mRNA is enriched in the pharyngeal arches (red arrowhead). In Snail CRISPR mutants, Snail expression is similar compared to wildtype embryos at both early (C, E) and late (D, F) stages of embryogenesis. Isolation and sequencing of these embryos revealed that they are true mutants (G).