Fig. 3. ed is independent of the R8 twinning mutants ro and sca. (A-I) Confocal microscopy of third larval instar eye imaginal discs. (A-E) Immunohistochemical detection of Ato (green) and Sens (red). (A) ed^4.12/ed^4.12. (B) ro^X63/ro^X63. (C) sca^BP2/sca^BP2. The phenotypes of the three mutants are distinct. (D) ed^4.12/ed^4.12;ro^X63/ro^X63. (E) ed^4.12,sca^BP2/ed^4.12,sca^BP2, twinning is not completely penetrant in D or E and arrows indicate single R8 cells. (F,G) Immunohistochemical detection of Ato (green) and Ro (red). (F) Wild type. (G) ed^4.12/ed^4.12, expression of Ato and Ro remains mutually exclusive in the ed mutant. (H,I) Immunohistochemical detection of Ato (green) and Sca (red). (H) Wild type. (I) ed^4.12/ed^4.12, the additional R8 precursors express Sca.