Extended Data Fig. 2: F-Cells lie adjacent to differentiating tactile bristles.

(a) Tactile bristle and the F-Cell (arrowhead) at 70 hAPF labelled by expression of the microtubule marker GFP::CLIP-170 (green) under control of neur > RFP. Note that the F-Cell associates with the socket cell. (b) Top: diagram of the cuticular socket and hair shaft. Bottom: detection of the F-Cell (arrowhead) next to the socket cell (dotted circle) by enhanced expression of Diap1-GFP (green) and co-labelling of the junctional network with E-Cad::TdTomato. (c) Diagram of the tactile bristles decorating the adult abdominal surface and the abdominal epidermis visualized at 65 hAPF. E-Cad::td-Tomato expression marks the junctional network and Diap1-GFP (green) labels the nuclei of the epidermal cells. F-Cells are identifiable by elevated Diap1-GFP in the epidermal cells next to each socket cell within the monolayered epithelium. (e) Diagram of the tactile bristles decorating the adult thoracic surface and pattern of Diap1-GFP in the thoracic epidermis at 50 hAPF. (d) Identification of the F-Cell (arrowhead) in the thoracic epidermis by the expression of Diap1-GFP and neur > RFP, and simultaneous expression of Jupiter::GFP (green) and neur > RFP (magenta) to highlight F-Cell position next to the socket and shaft cells. Results are representative of three independent experiments. Scale bars: 5 μm (a-b, e), 15 μm (c) and 20 μm (d). Full genotypes are listed in Supplementary Table 1.