Figure 3.

msk null mutant cells in the developing eye imaginal disc did not have distinct nuclear staining of phospho-Mad. (A) Third instar eye imaginal discs (anterior to the left) were stained with PS1, which specifically recognizes phospho-Mad (Mad-P, red). The nuclei were marked with DAPI (blue). The boxed area was magnified and shown as the three panels on the right. Bars, 10 μm. (B) msk⁵ (null) or wild-type clones were generated using FLP recombinase driven by the eyeless promoter. The third instar eye imaginal discs were stained for phospho-Mad (red) and nuclei (blue). The clones were marked as negative for GFP signal (black) and are outlined. Bar, 10 μm. (C) msk⁵ or wild-type clonal cells falling within the posterior phospho-Mad–positive stripe (5–6 cells wide) were scored as having concentrated phospho-Mad staining in the nucleus or not. The numbers are obtained from more than eight discs in each case.