Four single guide RNAs and SpCas9 targeting sequences CTTCATTGTATGAGCAGCCG, TTTGAAAGAGACAGCTGCCT, ACGCACGTCGGACAGTTCCA, and GGCTTATTGCGCACGCACGT flanking a chromosome 1 region were targeted in SS/JrHsdMcwi embryos. An 82-bp deletion in chromosome 1 (rn7: chr1:255,749,164-255,749,245) resulted.