Fig. 1. CtBP is required for Knirps repression of even-skipped (eve) stripe 4/6 enhancer, but not stripe 3/7 enhancer. Expression patterns of eve stripe 3/7 (A,B) and eve stripe 4/6 lacZ reporter genes (C,D) in wild-type (A,C) and CtBP mutant (B,D) embryos, showing derepression only of the eve stripe 4/6 element in the CtBP mutant. (E) Schematic representation of eve regulatory regions, showing cofactor requirements for Knirps repression. Expression patterns were characterized in transgenic embryos by in situ hybridization. Embryos are oriented anterior towards the left, dorsal side upwards.