Fig. 7. A deletion analysis identifies an upstream regulatory element important for ced-9 transcription. (A) Clones tested for ced-9::gfp expression and ced-9 rescue. The sequences coding for GFP are inserted into a unique PstI site in the third exon of ced-9. Deletions 1-3 correspond to three deleted clones that center on a potential Pax response element, indicated with a black bar on the clones. In the mutant clone, this element is altered, indicated by `X'. The sequence for both the wild-type and the mutant element is shown below the diagram. (B-I) Expression of the full length ced-9::gfp clone in embryos [(B,F) prior to elongation, (C,G) at comma stage, (D,H) at 1.5-fold stage] and (E,I) in adult gonad. (B-E) DIC images. (F-I) The same animals under epifluorescence to visualize GFP. In I, the bend of the gonad arm is shown and the ced-9 expression is marked with a bracket. (J-S) Representative embryos bearing each of the transgenes summarized in A. (J-N) DIC images. (O-S) The same embryos under epifluorescence to visualize GFP. All embryos are at a stage similar to that shown in B and F.