Fig. 1. DMKP3 is an ERK phosphatase. Eye sections (left), wings (middle) and cuticle preparations (right) of strains overexpressing the indicated phosphatases by sev-GAL4, en-GAL4 and 69B, respectively. Wild-type controls are shown in A-C. Eyes and wings are not affected by overexpression of mammalian M3/6 and Drosophila puckered (D,E,G,H), but by MKP-3 and Dmkp3 (J,K,P,Q). The latter two do not impair embryogenesis (L,R), but the JNK phosphatases cause a dorsal closure defect (F,I). CL100 interferes with all processes (M-O) and even leads to wing duplications (N, lower). Driver lines were sev-GAL4^K25 (D,G,J), sev-GAL4^KK12/3 (M,P), en-GAL4³³ (K,N — upper wing) and en-GAL4⁵⁴ (E,H,Q,N — lower wings). en-GAL4 is expressed in the posterior wing region. The wing shown in K harbors two copies of the MKP-3 transgene and the wing in Q is derived from a male.