The FRT cassette containing the E(spl)mδ-HLH gene has been excised from M{E(spl)-mδ(FRT)-mβ(FRT)-m3GFP}ZH-51D, resulting in a genomic fragment at the location of the M{3xP3-RFP.attP}ZH-51D docking site on the second chromosome that encompasses the entire E(spl)-complex but lacks both the E(spl)m3-HLH and E(spl)mδ-HLH open reading frames (the E(spl)m3-HLH open reading frame has been replaced by the sfGFP coding region).
Dp(3;2)E(spl)-m3null,mδnull/Df(3R)BSC751 mutant embryos display a significant increase in the number of EL neurons (but not Ap neurons), as compared with controls.