Deletion that removes most of the ctg coding sequence. A sequence cassette encoding 1. the GAL4::VP16 coding sequence and 2. a loxP cassette containing a Disc\RFP3xP3.cUa marker has been inserted in place of the deleted sequence. The inserted sequence is flanked by a pair of inverted attP sites, and can thus act as a target for recombination-mediate cassette exchange (RMCE).