The snRNA:U6:96Ac promoter drives expression of four sgRNAs. Three of them (AAGTATAGAGGTCGCTGCCC, ATAGTTTGGGATCCTTGGAC and CATAACATTGTGGTAACAGG) target exon 2 of WDY, and the other (GCCACAATTGTCGATCGTCA) targets e (a visible Co-CRISPR marker).