Fig. 5. Snail family of proteins regulate string expression in neuroblasts. RNA in situ hybridization was carried out using antisense string probe on wild-type (A), osp29 mutant (B) and P[wor, esg]-carrying mutant (C) embryos. After in situ hybridization, the embryos were embedded in Epon plastic and 3 µm sections were cut and representative sections are shown here. The arrows in panels A and C indicate RNA expression of string in neuroblasts. Staining is also seen in ectodermal cells. The neuroblast layer is located between the ectoderm and the mesoderm (A). The osp29 mutant embryos also have more folding, indicating gastrulation defects. Nonetheless, the ectodermal staining is clear but the neuroblast staining is largely absent (B). The transgenes can partially rescue expression of string in the neuroblasts (C).
