Fig. 1. ed expression pattern during embryogenesis. ed RNA (A,B) and protein (C-H) expression in wild-type embryos. In stage 9 embryos (A-D), differential expression of ed is evident. Whereas ed is expressed in the neuroectodermal (NE) and mesodermal (ME) cell layer, no expression is detected in the delaminated neuroblasts. (B,D) Enlarged lateral views of the ventral regions of embryos in A and C, respectively. The NE and ME cell layer are indicated and the bracket spans the layer where delaminated neuroblasts are located. (E) By stage 11, Ed expression ceases in the ventral neurogenic region and becomes restricted to the tracheal pits, marked by the asterisk, and the epidermis. At late stage 13, Ed can be detected in a subset of cells in the developing CNS and also in the epidermis (F). During stage 14, Ed expression is limited to the anterior and posterior epidermal stripes (H). At stage 16, Ed is highly localized to the axons with a higher concentration in the posterior commissures (G). A and P refer to anterior and posterior commissure, respectively.