Fig. 6. The Ap-dLMO fusion protein dLAp is functional. (A) Domain organization of Apterous, dLMO and dLAp-flag. For the fusion protein dLAp-flag, the LIM-domains of Apterous were replaced by the LIM-domains of dLMO. In addition, dLAp contains a C-terminal flag-tag to make it distinguishable from the endogenous Ap and dLMO proteins. (B) Confocal image of a third instar wing imaginal disc of the genotype dpp^Gal4; uas-dLAp-flag stained with anti-Ap (red) and anti-Wg (green). Endogenous Ap protein barely detectable as faint red label in the dorsal compartment. The intense red stripe reflects overexpression of dLAp in the dpp^Gal4 domain. The Wg stripe follows the border between dLAp-expressing and non-expressing ventral cells. (C) Cuticle preparation of an ap^Gal4/ap^UGO35wing. The heteroallelic combination ap^Gal4/ap^UGO35 shows strongly reduced Ap activity but retains Gal4 expression in the Ap domain. (D) Cuticle preparation of an ap^Gal4/ap^UGO35; uas-dLAp-flag wing. Expression of the uas-dLAp-flag transgene in this domain is able to support wing development, indicating that it can provide Ap function. (E) Cuticle preparation of a dpp^Gal4; uas-dLAp-flag wing. Overexpression of dLAp along the AP boundary by dpp^Gal4 leads to the formation of ectopic wing margin in the ventral compartment (arrow).