Loss of dcst2 expression in male zebrafish is not associated with muscle hypertrophy

Recently, a large family of French-Canadians was found to possess above-average strength and muscle hypertrophy that segregated with a single variant in the gene encoding Dendritic Cell-specific Six Transmembrane domain containing protein 2 (DCST2). To investigate the potential role DCST2 has in muscle cell biology we used the CRISPR/Cas9 mutagenic system and generated a 2-nucleotide deletion in exon 3 of zebrafish dcst2 resulting in a frameshift mutation. Homozygous carriers of the mutation displayed reduced transcriptional expression of dcst2 suggesting that our mutation disrupted gene expression. Homozygous mutant dcst2 zebrafish developed normally to adulthood and displayed no differences in motor function using a free-swim and swim tunnel assays. Furthermore, histological examination of muscle cells revealed no differences in slow-twitch or fast-twitch muscle cell cross-sectional area in our mutants. We did observe that male dcst2^-/- zebrafish were infertile. The data collected here, suggest that dcst2 does not play a role in zebrafish muscle cell biology.