Fig. 7. ey mutant clones in the eye disc express DLL. (A) Genomic organization of the ey region. The nine exons of the ey gene are indicated as turquoise boxes. The areas coding for the PD are highlighted in blue and the areas coding for the HD in red. The extent of the ey^J5.71 deletion is indicated by a gray box. The DOC-element insertion of the ey² mutant into the second intron of the ey gene is indicated by a triangle. The two genomic P-element clones and the respective genomic areas they cover are marked below. (B) Flies generated to perform the cross for the clonal analysis. Larvae that were y^– (25%) were dissected for antibody staining. (C-F) Antibody staining on eye discs where mutant clones were induced. DLL expression is shown in red, GFP expression in green recapitulates the smo enhancer expression domain in the posterior part of the disc. Posterior mutant clones are marked by a lack of GFP expression. Only clones visualized in the posterior domain of the eye disc are shown. DLL expression was never detected in cells present in the ey domain (anterior part of the eye disc) in ey^–/– cells. Anterior clones were detected by the use of an ey antibody. (C) Shows the entire eye-antennal disc with DLL expression in the antenna and a clone of DLL-expressing cells in the eye disc. (D-F) Magnification of the image shown in C. (D) Merged image of GFP (E) and DLL (F) expression. (G) Antibody staining with the rabbit -EY antibody where clones were randomly induced. Lack of EY protein is only visible in the anterior part of the eye disc (where EY is expressed). Brighter twin clones have two copies of the ey transgene (arrows).