Fig. 2. Egfr regulates DV pattern in the neuroectoderm through genes other than vnd and ind. High-magnification ventral views of the neuroectoderm of stage 9 (A-C) and late stage 8 (D-I) wild-type (A,D), ind (B,E), Egfr (DER; C,F), vnd; ind (G), vnd; Egfr (vnd;DER; H) and vnd; Dichaete ind (I) mutant embryos labeled for NBs (A-C) or msh expression (D-I). (A) In wild-type embryos, NBs occupy three columns: medial (m), intermediate (i) and lateral (l). (B) In ind embryos, intermediate NBs do not form and medial and lateral NBs are separated by a gap (bracket and arrows). (C) In Egfr embryos, intermediate NBs do not form and medial and lateral NBs reside adjacent to each other (arrows). (D) In wild-type embryos, msh expression is restricted to the lateral column. (E) In ind embryos msh expression expands into the intermediate column. (F) In Egfr embryos, msh expression expands into the intermediate column and partially into the medial column. (G) In vnd; ind embryos, msh is expressed throughout the neuroectoderm with higher expression laterally (arrowheads) than ventrally (arrows). (H) In vnd; Egfr embryos and in (I) vnd; Dichaete ind embryos, msh is expressed uniformly throughout the neuroectoderm. Anterior is towards the left and the line indicates the ventral midline.
