Figure 6
From: Cap’n’collar differentiates the mandible from the maxilla in the beetle Tribolium castaneum
Expression of the Hox genes Tc-Dfd and Tc-mxp in wild-type and Tc-cncRNAiembryos. Knockdown of Tc-cnc by RNAi results in transformation of the mandibular appendage to maxillary identity and the expression of Hox genes in a similar manner to that seen in the maxilla. All views are ventral with anterior to the left. Expression of Tc-Dfd (blue) and Tc-mxp (red) was determined by in situ hybridization. Mandibular segment is indicated with an arrowhead, maxillary segment with a black arrow. Mesodermal expression of Tc-mxp is indicated with a white arrow. (A,C,F) Wild-type Tribolium embryos. (B,D,E,G-I) Tc-cncRNAi embryos. (A) Wild type germ band extending embryo. Tc-mxp is expressed in the developing maxillary and labial palps and the mesoderm in the mandibular segment (white arrow). (B) Tc-cncRNAi germ band extending embryo: Tc-mxp expression is present in the transformed mandibular appendage (arrowhead) in a telopodite domain consistent with the transformation of the mandible to maxillary identity. (C) Wild-type germ band retracting stage embryo. Tc-Dfd expression has retracted from the majority of the mandibular appendage. (D) Tc-cncRNAi embryo at a similar stage to C. Tc-Dfd expression is present in the transformed mandibular protopodite (star). Tc-mxp is expressed in the transformed mandibular appendage palp. (E) Higher magnification of the earlier germ band extending stage Tc-cncRNAi embryo shown in B. (F) Higher magnification of the gnathal appendages of a germ band retracting stage at a similar stage to C. (G, H, I) Higher magnification of the gnathal appendages of germ band retracting stage Tc-cncRNAi embryos. (G) Tc-Dfd is expressed throughout the transformed mandibular appendage, in the lacinia endite (star) and galea endite (asterisk). Tc-mxp is expressed in the palp (arrowhead) as well as the galea endite in a manner that is identical to the maxilla (arrow). (H) The mesodermal expression domain of Tc-mxp (white arrow) is observed in the transformed mandibular appendage. (I) Tc-Dfd is expressed throughout the maxilla, the rounded kink at the base of the maxilla is indicated (star).