Fig. 2. Changes in Hox gene expression in Tc'hb^pRNAi embryos. Wild-type expression is shown in A,C,E,G,I; expression in loss of hunchback embryos (strongest phenotypes) is shown in B,D,F,H,J. All embryos are double stained with a Tc'gsb probe, which serves as a segmental reference marker. Tc'gsb staining is brown in A-F and dark purple in G-J. Hox gene staining is the reverse. (A,B) Tc'Dfd expression extends over the mandibular and maxillary segment in wild type (A) and is lost from the maxillary segment in Tc'hb^pRNAi embryos (B). (C,D) Tc'Scr expression covers the labial segment (arrow) in wild type (C) and is lost in Tc'hb^pRNAi embryos (D). (E,F) Tc'Antp expression covers the thoracic and abdominal region in wild type (E) with a stronger expression in the thoracic segment (double-headed arrow). In Tc'hb^pRNAi embryos, Tc'Antp expression is shifted towards anterior up to the mandibular segment, but its intensity is comparable with the wild-type expression of Tc'Antp in the abdominal segments (F). (G,H) Tc'Ubx expression starts in the third thoracic segment and extends throughout the abdominal region in wild-type embryos (G), with a stronger expression in the first abdominal segment (arrowhead). In Tc'hb^pRNAi embryos, Tc'Ubx expression is shifted towards anterior up to the mandibular segment (H), but its intensity is comparable with the wild-type expression of Tc'Ubx in the abdominal segments (arrows in G,H). (I,J) Tc'Antp expression starts in the second abdominal segment and extends throughout the abdominal region in wild-type embryos (I). In Tc'hb^pRNAi embryos, Tc'Antp expression is shifted towards anterior up to the mandibular segment (J).