A sequence cassette containing 1. a snRNA:U6:96Aa promoter driving expression of a gRNA that targets w, 2. a snRNA:U6:96Ac promoter driving expression of a gRNA that targets y, and 3. a Disc\RFPDsRed.3xP3.cUa marker, has been inserted into the endogenous y locus. Used as part of a split gene-drive system.