Fig. 4. GMC formation is defective in the absence of Snail family of proteins. All embryos are approximately at stage 11. (A-C) Ventral view. (D-F) Sagittal views of embryos. (A,D) Wild type; (B,E) Df(2L)osp29 mutant; (C,F) osp29 with P[wor, esg] transgenes. The Prospero protein staining is largely absent in the deletion mutant (B). More cells show staining in the midline (ML), probably owing to the derepression of midline determinants in the absence of Snail (see also Fig. 3F). Transgenes of worniu and escargot rescued Prospero expression efficiently (C). Similar results are also observed in the presence of snail transgene (data not shown). Hunchback (Hb) at this stage is present in many GMCs (D). The brackets in D-F indicate where Hb-positive GMCs are seen in wild-type and rescued embryos but absent in osp29 mutant embryos.
