Expression of Wg (A–D) and Gsbn (E–H) proteins in wild-type (A, E), homozygous Df(2R)IIX62 (B–D) or transheterozygous Df(2R)IIX62/gsb525 (F–H) gsb mutant embryos carrying no (B, F), one copy of the gsb-Prd (C, G) or gsb-Pax3 (D, H) transgene. Embryos at stage 13 (A–D) or stage 10 (E–H) are oriented with their anterior to the left and dorsal side up. Embryos were collected from crosses between Df(2R)IIX62/CyO, hb-LacZ; gsb-Prd/+ or Df(2R)IIX62/CyO, hb-LacZ; gsb-Pax3/+ males and Df(2R)IIX62/CyO, hb-LacZ (A–D) or gsb525/CyO, hb-LacZ females (E–H), and double stained for ß-galactosidase and or Gsbn protein with rabbit antiserum against ß-galactosidase and anti-Wg monoclonal antibodies or rabbit anti-Gsbn antiserum. Embryos stained with ß-galactosidase have at least one copy of wild-type gsb allele and were used as control (A, E). One quarter of the embryos did not stain for ß-galactosidase. Half of these embryos did not express Wg in the ventral epidermis and Gsbn in the CNS as expected for gsb mutants. The other half displayed rescued expression patterns, which suggested the presence of the transgenes. Scale bar: 100 um.