UASp regulatory sequences drive expression of spg; the sequence is a genomic/cDNA hybrid and has been rendered resistant to RNAi by the P{TRiP.GL00316} line by synonymous mutations in the sequence targeted by the P{TRiP.GL00316} shRNA (CCCGAACTGATTATCAAGAAA mutated to CCAGAGCTAATCATTAAAAAG). The coding sequence is tagged at the N-terminal end with EGFP.