Figure 5

Anatomically and molecularly defined epithelial placode for cranial dermal denticles. (A) Whole-mount in situ hybridization of pitx2 in Ancistrus sp. embryos at 48, 60, 72 hpf, and 96 hpf. Pitx2 expression in developing dermal denticles was discerned at 60 dpf. Each number indicates cranial dermal denticles and the numbering is consistent in all panels. Scale bars: 100 µm. (B) Immunostaining of PCNA (green) and cell membrane (DiI labeling, red) with nuclear staining (DAPI) (top), and in situ hybridization of pitx2 for transverse sections at the position of the dotted line in A (bottom). Pitx2 transcripts were detected in the anatomically defined placode (white brackets; thickened epithelial tissue with the reduction of cell proliferation). White and black dotted lines indicate a boundary between epithelium and mesenchyme. Black solid line in pix2 panel indicates a boundary between the top and bottom layer of epidermis. Scale bars: 100 µm. (C) Schematic illustration of the cranial dermal denticle placode. At least three biological replicates were investigated in each experiment.