Single nucleotide deletion at +926bp relative to the nau transcription start site. This causes a frame shift at amino acid 177, within helix 1 of the bHLH domain.
Deletion of the G base in codon V177 causing a frameshift after amino acid 177.
Homozygous embryos have a somatic muscle phenotype, in which only a small subset of somatic muscles is affected, including muscles DO4 and DA3.