nc 11 (A, C, E, G) and 12 (B, D, F, H) embryos carrying sog(A–D) or brk(E–H) transgenes were hybridized with RNA probes synthesized against intronic sequences of the yellow reporter gene. Dl antibody staining (not shown) was used to orient embryos. DAPI stained nuclei expressing yellow reporter gene are pseudo-colored in yellow. Compared to the sog wt enhancer (A, B), mutation of all Zld sites in the sog NEE (sog 0; C, D) results in delayed and sporadic expression. (E–H) Embryos carrying the brk enhancer with added Zld sites (brk +3a; G, H) have advanced initiation of transcription compared to embryos carrying the brk wt enhancer (brk wt; E, F). (I) Table showing the number of embryos carrying the four transgenic lines that display any expression from nc 9 to nc 12.