Fig. 1. Overexpression of Arm alleles in embryos using the GAL4/UAS system. The two alleles, Arm and S10, both produce the same activated wg signaling phenotype in first instar larval cuticles, but Arm localizes to the membrane while S10 localizes to the nucleus. (A) Phase contrast images of cuticle preparations of ArmGAL4 crossed to either Arm, or S10. A wild-type cuticle is shown for comparison. The ventral side of all embryos is shown. (B) Confocal microscope images of embryos using the ArmGAL4 driver to drive expression Arm (-HA, red), S10 (-c-Myc, red), and UAS-full-length-Arm (rAb, green). (C) Using the maternal GAL4 driver, 67.15, expression of Arm (-HA, red), endogenous Arm protein (rAb, green), and nuclei (Hoechst, blue) is shown. Lower panel shows a close up of the same embryo. The amino-terminal deletions in S10 and Arm delete the epitope used to make the Arm antibody allowing staining of expressed protein and endogenous protein without cross-reactivity. Overexpressed full-length Arm shows both endogenous and expressed protein.