The Obp50a-Obp50b-Obp50c-Obp50d cluster has been replaced with a attP-loxP-DsRed-loxP cassette. A single nucleotide substitution in each protospacer adjacent motif (PAM) was necessary to prevent Cas9 from cleaving the template, which resulted in CG34444 G233A and CG34185 G113A substitutions.