Glutamic acid codon 80 (GAG) in exon 3 was changed to alanine (GCG) (p.E80A) using an sgRNA and an ssODN template with CRISPR/Cas9 technology. The mutation, in the homeodomain (HD) of the encoded peptide, is the equivalent of the same human mutation associated with dominant cone-rod dystrophy 2 (CRD2). (J:343281)