Fig. 5. cmn is required in the posterior compartment. (A,A') A wing disc carrying a large clone of cmn mutant cells was stained to show the expression of ptc-lacZ (red) and a GFP marker gene (green). cmn mutant cells are identifiable by the lack of green staining. Anterior compartment cells near the AP compartment boundary express ptc-lacZ (arrowhead) at wild-type levels even though they are mutant for cmn. (B,B') A wing disc carrying a large clone of cmn mutant cells (marked by the lack of green staining) in the posterior compartment has lost ptc-lacZ expression in adjacent anterior compartment cells (arrowhead).