Fig. 7. smo and tkv signaling affect pMAPK and Atonal expression. Third instar eye-imaginal discs with mutant null clones (outlined); anterior to the right; all to the same scale as indicated in L. Genes homozygous in the clones are indicated on the left, antigens/stains above; arrowheads indicate the furrow. (A-D) smo null clones showing reduced Atonal and pMAPK expression (asterisk). Note, residual Atonal is strongest in the lone R8 cells (arrow in B,D). (E-H) tkv null clones showing of Atonal and pMAPK (arrows). (I-L) smo tkv double-mutant clone in which Atonal and pMAPK expression is lost (asterisk).