Comparison of the number of ectopic bristles (macrochaetes) displayed by transgenic flies after ectopic expression. UAS constructs containing D. melanogaster ase, T. castenum ase and C. salei CsASH2 (ORF alone or the entire transcribed region (ORF+SOPE) of ase or CsASH2) were each crossed to four different Gal4 drivers allowing expression in different parts of the thorax (see Materials and methods). (A) The number of ectopic bristles was counted in the respective Gal4 expression domains of each of the driver lines. Columns give the number of ectopic bristles and data from all four crosses have been pooled for each UAS construct (UAS-ORF+SOPE or UAS-ORF). The number of ectopic bristles is significantly reduced in flies carrying the UAS-ORF+SOPE constructs (see Additional file 4 for details). The error bars give the standard error of the mean. (B-G) Thoraces illustrating the phenotypes obtained: (B, C) ptc-Gal4 > UAS Dm-ase; (D, E) sca-Gal4 > UAS Tc-ase; (F, G) MD806-Gal4 > UAS CsASH2.