Fig. 2.
sanpodo misexpression inhibits Notch signaling during lateral inhibition and wing development in a numb-dependent manner. (A) Four scutellar bristles arise in wild type. (B) Removing one copy of Notch has little effect on bristle number. (C-E) Expression of spdo by patched-GAL4 (o/e spdo) in the scutellar region promotes ectopic bristle formation (C), a phenotype enhanced by reducing Notch function 50% (D), and suppressed by co-expression of a numb-RNAi transgene (E) (Tang et al., 2005). (F) In wild type two sensory organ precursors, as labeled by anti-senseless (Nolo et al., 2000), develop in the scutellar region (arrows, brackets) of the late third instar wing imaginal disc. (G) spdo overexpression in this region promotes the formation of ectopic sensory organ precursors (arrow). (H) Average number of scutellar bristles per indicated genotype. Error bars indicate s.d. **P<10−4; ***P<10−10. (I) nubbin-GAL4-mediated expression of spdo in the wing (o/e spdo) leads to wing notching, vein thickening and reduced wing size. (J) Reduction of Notch function by 50% (N+/−; o/e spdo), using the Notch81k1 allele, enhanced these phenotypes. (K,L) Simultaneously reducing numb function by 50% (N+/−; numb+/−; o/e spdo, L) suppressed the phenotypes observed in N+/−; o/e spdo flies (K). Images in I-K are shown at identical magnification.