(A) EMSA analysis of the BgFTZ-F1 protein translated in vitro. The protein sample was incubated with 32P-labeled F1RE-S1a response element. The specificity of the interaction was tested by the addition of 100-fold molar excess of unlabeled F1RE-S1a and F1RE-S1b elements. The identity of the complex was tested with the addition of anti-BgFTZ-F1 antibody (anti-BgFTZ-F1) and pre-immune serum (pre-imm. serum). (B) Identification of BgFTZ-F1 protein in CA nuclear extracts (CA NE) of B. germanica 5-day-old adult females. The identity of the complex was tested with the addition of anti-BgFTZ-F1 and pre-imm serum, as well as with the analysis of CA NE from dsBgFTZ-F1-treated adults from the same age. (C) Developmental profile of BgFTZ-F1 protein present in CA NE from penultimate (N5) and last (N6) instar nymphs, as well as adult females incubated with labeled F1RE-S1a element. 20 CA equivalent was used in each binding reaction. (D) Developmental profile of BgFTZ-F1 protein present in CA NE from females of the first gonadotrophic cycle incubated with labeled F1RE-S1a element. Arrows in (A–D) indicate the BgFTZ-F1-F1RE-S1a complex. Arrowheads in (A and B) indicate supershifted BgFTZ-F1-F1RE-S1a complexes due to the addition of anti-BgFTZ-F1.