Fig. 3. Sxl shows graded nuclear entry along the AP axis of wild-type wing discs. (A-C) Wing pouch of disc stained for Sxl (A) and with propidium iodide (B). (C) Merged image of A and B. Sxl is mostly cytoplasmic and the nuclear stain is primarily unaltered in C in most of the cells. Insets are enlargements of region from the top right of image. Scale bar: 20 µm. (D-F) Disc treated with 100 ng/ml LMB for 3 hours stained for Sxl (D) and full-length Ci (E). (F) Merged image of D and E. Arrowheads show that besides the posterior compartment, there is more nuclear Sxl (brighter signal) at the AP boundary where the signals for Sxl and Ci overlap. Inset in D is of a region at the AP boundary. There are no distinct nuclei visible as the protein is not entirely nuclear but punctate regions of more intense staining. Scale bar: 40 µm. (G-I) Disc treated with high levels of LMB (250 ng/ml for 3 hours) stained for Sxl (G) and with propidium iodide (H). (I) Merged image of G and H. Insets are enlargements of the region in the middle of the disc at the AP boundary. Although there is more Sxl in the nuclei (note the overlap in the two signals and change in color, in contrast to C), there still is some protein in the cytoplasm; green signal around orange nuclei and inset. Bar is 20 µm. All are confocal images; anterior is to the left, ventral at the top.