Fig. 4. Single-minded is specifically expressed in lamina under the control of Hh signaling. (A,B) Single-minded (Sim) is expressed specifically in lamina neurons. Sim (white) and Dac (blue) protein are visualized by immunofluorescence microscopy. (C) A magnified image of the boxed area of B. Nuclei of the lamina neurons were visualized by NP6099-GAL4 UAS-nlsGFP in C'. Note that nuclear localization of Sim is obscure in the anterior (left side) and obvious in the posterior (right side) region. (D) A marginal level of Sim expression (white) is detected in the eye disc. Dac (blue) is expressed at the morphogenetic furrow. (E-G) Sim expression is cell-autonomously abolished in smo mutant clones. smo mutant clones (arrowheads) are visualized by the absence of GFP (green); Sim (magenta) and Dac (blue in E; cyan in G) were visualized by immunofluorescence microscopy.