CRISPR/Cas9 technology using gRNA 5-CACCACAAACACCGATGACTTGG-3 targeting exon 3 (the first coding exon) of both Myh1 and Myh4 genes generated a G to C point mutation and a single nucleotide deletion (T) in Myh1. This targeting event also generated a single nucleotide insertion in Myh4 (Myh4em1Ktsu) in this line. (J:335578)