Fig. 4. Expression patterns of Hox genes in embryos depleted of Gb'hb by RNAi. (A) Wild-type embryo stained for Gb'abdA. Gb'abdA is expressed in the posterior compartment of A1 and the remaining abdominal segments. (B-D) Putative class III-I embryos stained for Gb'abdA. Ectopic expression of Gb'abdA in gnathal and thoracic regions was observed in B and C, suggesting that the strong phenotype (D) consists of transformed gnathal and thoracic segments and a shortened abdomen. (E) Wild-type embryo stained for Gb'Scr. Gb'Scr is strongly expressed in the labial and T1 segments. Expression in the labial segment is more intense than in the T1 segment. (F-H) Putative class III-I embryos stained for Gb'Scr. Gb'Scr expression in the labial and T1 segments was gradually reduced as the phenotype became more severe. (I) Wild-type embryo stained for Gb'Antp. The anterior boundary of the Gb'Antp expression is the T1 segment. (J-L) Putative class III-I embryos stained for Gb'Antp. The anterior boundary of the Gb'Antp expression was shifted to the labial segment in all phenotype classes. The strong midline expression in the anterior region is an abdomen-like pattern and probably ectopically induced. (M) Wild-type embryo stained for Gb'Ubx. Gb'Ubx is strongly expressed in the T3 legs and A1 prolegs, and weakly expressed in the abdominal segments. In the abdomen, the intensity of expression follows a gradient from anterior to posterior. (N-P) Putative class III-I embryos stained for Gb'Ubx. (N) Expression patterns of Gb'Ubx indicates that the leg most resistant to RNAi (arrowhead) was T3. Strong expression of Gb'Ubx in the A1 prolegs was also detected in this class of embryos (arrow). Scale bar: 250 µm.