Fig. 6. Egfr regulates Dichaete expression in the neuroectoderm. (A-D) Ventrolateral views of whole-mount stage 8 (A-D) and high-magnification ventral views of stage 11 (E-H) wild-type (A,E), vnd (B,F), Egfr (DER; C,G) and vnd; Egfr (vnd; DER; D,H) mutant embryos labeled for Dichaete. (A) In stage 8 wild-type embryos Dichaete is expressed in the medial and intermediate columns. (B) In vnd embryos, Dichaete expression is normal during stage 8. (C,D) In stage 8 in Egfr (C) or vnd; Egfr (D) embryos, Dichaete expression is strongly reduced in the intermediate column and moderately reduced in the medial column. (E) In stage 11 wild-type embryos, Dichaete is expressed in the medial and intermediate columns, and in one or more lateral column NBs. (F) In stage 11 vnd embryos, Dichaete is expressed in an irregular stripe two-to-four cells wide immediately adjacent to and on either side of the ventral midline (arrows). (G) In stage 11 Egfr embryos, Dichaete is expressed in an irregular stripe of cells zero to three cells wide immediately adjacent to and on either side of the midline (arrows). (H) In stage 11 vnd; Egfr embryos, Dichaete is not expressed in the neuroectoderm but is expressed in the ventral midline (arrowhead) and lateral NBs. Anterior is towards the left; white arrowheads (A-D) and lines (E-H) indicate ventral midline.
