Fig. s7

ET37:EGFP labels all dermal cells. Confocal images of vibratome sections through skin of ET37:EGFP transgenic larvae, counterstained with Cellbright membrane dye. (A) At 7.2 SSL, EGFP was expressed in a monolayer of cells beneath the epidermis, representing the primary hypodermis. At 8.6 SSL, the primary hypodermis was becoming a multilayered dermis. At 9.6 SSL, scale papillae and extending scales were present. ET37:EGFP was expressed in all papillar cells and in a subset of cells at the posterior margin of the scale. (B) Dermal cells labeled by ET37:EGFP included cells with projections extending from the cell body in a deep stratum of the developing dermis into a more superficial stratum towards the epidermis, as exemplified in this higher magnification image of the outlined region in A at 8.6 SSL. (C) ET37:EGFP+ cells beneath scales were embedded in a thick collagenous stroma, as revealed by contrasting horizontal lines associated with fibrillar collagen in merged brightfield and fluorescence channels of the boxed region in A at 9.6 SSL. Each image is representative of sections from at least four individuals. Scale bars, 100 μm.