UAS regulatory sequences drive expression of 4 sgRNAs (ATTCGACAGCGTCCTGAATCCGG, GCTTGGCGTCACCCGGATTCAGG, CGCCGACTCCACCTACGACGCGG and CTGGGAGCCCGCGTCGTAGGTGG), each of which targets yki. The sgRNAs are expressed as a single polycistronic tRNA-gRNA cassette.