Fig. 4. Graded Ft expression can direct ommatidial polarity. (A) Anti-Ft antibody staining of a wild-type eye imaginal disc. Anterior is left, dorsal up. Ft is expressed in a uniform pattern along the dorsoventral axis at the morphogenetic furrow (arrowheads). (B) Anti-Ft antibody staining of a w¹¹¹⁸; fj^Vg1-Gal4/+; UAS-Ft/+ eye imaginal disc. Ft expression is elevated in the equator region and drops in a graded fashion towards the poles of the disc. (C) Anti-Ft antibody staining of a w¹¹¹⁸, Omb3-Gal4/w¹¹¹⁸; UAS-Ft/+ eye imaginal disc. Ft expression is slightly elevated near the poles (yellow arrow) and drops rapidly towards the equator. The inset is a magnified view of the arrowed region. (D-I) Schematics of representative sections of adult eyes. Relevant changes from wild type with regard to Ft and Fj function or expression are indicated at the bottom of each panel. The schematics along with the sections on which they are based are presented in Fig. S3 in supplementary material. (D-F) Equatorial sections; (G-I) polar sections. (D) w¹¹¹⁸; ft^G-rv/ft^l(2)fd; TubP-Gal4/UAS-Ft. (E) w¹¹¹⁸; TubP-Gal4/UAS-Ft. (F) w¹¹¹⁸; fj^Vg1-Gal4/+; UAS-Ft/+. (G) w¹¹¹⁸, Omb3-Gal4/w¹¹¹⁸; UAS-Ft/+. (H) w¹¹¹⁸, Omb3-Gal4/w¹¹¹⁸; fj^N7/ds^UA071, fj^d1; UAS-Ft/+. (I) w¹¹¹⁸; fj^N7/ds^UA071, fj^d1.