UAS regulatory sequences drive expression of four sgRNAs; two target fz2 (sgRNA sequences ATACCAATGTGTCGGGGCATTGG and GGATCCCAATCTGCGATGCGAGG) and two target fz4 (sgRNA sequences TCCATGCCATCGGTCCGTGCCGG and CTGCAGTCGTATTCGATCAGTGG). The sgRNAs are expressed as a single polycistronic tRNA-gRNA cassette.