β-galactosidase expression in the fat body of larvae and prepupae of the Fbp1-97bp transgenic line. (A) 96 h third instar larvae, (B) 100 h third instar larvae and (C) 0 h prepupae. Reporter gene expression was detected after 1 h incubation in the presence of X-gal. The arrows indicate the trachea (t), proventriculus (p), imaginal discs (id), salivary glands (sg), brain (b), ventral ganglion (g), midintestine (mi), fat body (fb) and ring gland (rg), respectively. The blue staining detected in the imaginal discs (id) and in the midintestine (mi) corresponds to endogenous β-galactosidase activity .