Fig. 6. Some Notch functions are unaffected by spl. (A) Clone of spl mutant cells revealed by absence of ß-galactosidase (magenta; left and right). Atonal expression (green; left and middle) initiates similarly in spl mutant and wild-type territories. Maintenance of Atonal in R8 cells is defective in spl mutant territories (arrow). (B) Clone of spl mutant cells revealed by absence of ß-galactosidase (magenta; left and right). Senseless expression (green; left and right) initiates similarly in spl mutant and wild-type territories. Maintenance of Senseless in R8 cells is defective in spl mutant territories (arrows). (C) m0.5-lacZ reporter expression predominantly in R4 cells of wild-type retina. (D) m0.5-lacZ reporter expression only in R4 cells of spl mutant retina. Expression is absent from some ommatidia where R4 cells may be affected. (E) Sections through spl mutant eyes reveal ommatidia containing multiple cells of R7-like morphology (arrow). This aspect of the spl phenotype is not cell autonomous in mosaics (not shown).