Fig. 1. Adult mbt eye phenotype. Tangential sections through wild-type (A) and mbt^P1 (B) eyes. In the wild type, each ommatidium contains eight photoreceptor cells. R1-R6 have large rhabdomeres, the central R7 and R8 (not seen in apical sections) rhabdomeres are small. Longitudinal sections through wild-type (C) and mbt^P1 (D) eyes show the defects in proximodistal rhabdomere extension in the mutant. Scale bar: 10 µm.