Fig. 5. The dimA^– mutant exhibits pstO patterning defects. (A-D) Expression pattern of the prestalk specific ecmAO/lacZ reporter at the late finger stage of development. Mutant slugs show a greatly reduced zone of expression. (A,B) Several representative samples are shown. (C,D) Higher magnification highlights the shortening of the prestalk zone in the mutant (brackets). (E-H) Expression pattern of the prespore specific pspA/lacZ reporter at the late finger stage of development. (E,F) Representative samples show that the marker is expressed throughout the prespore zone of wild-type and mutant slugs. (G,H) Higher magnification highlights the small size of the unstained prestalk zone in mutant structures (brackets).