Extended Data Figure 3: Validation of somite specific photoconversion of Tg(tbx6:gal4-vp16); Tg(UAS:Kaede) double-transgenic embryos.
From: A somitic contribution to the apical ectodermal ridge is essential for fin formation

a–q, Photoconversion of somite 4–7 (a–k) and somite 4 (l–q). a, Schematic representation of photoconversion. b–d, Dorsal views after photoconversion of somite 4–7 at the 15 somite stage reveals non-photoconverted Kaede (green) (b) and photoconverted Kaede (red) (c). Merged image shown in d. Somites 1–7 are numbered. e–g, Lateral views of the same photoconverted embryo at 2 dpf, revealing non-photoconverted Kaede (e) and a photoconverted Kaede (f). Merged image shown in g. h, Close-up view of photoconverted somites from e–g including brightfield. i–k, Close-up view of pectoral fin shown in e–g showing non-photoconverted Kaede (i) and photoconverted Kaede (j). Merged image shown in k. Asterisks indicate presumptive fin muscle progenitors, arrows mark photoconverted Kaede-positive cells of the PHM (e–g) and presumptive vasculature (i–k), arrowheads indicate photoconverted Kaede-positive cells in the AER. l–n, Dorsal view after photoconversion of somite 4 at 15 somites, showing non-photoconverted Kaede (l), photoconverted Kaede (m), and merged image (n). Somites 1–6 are numbered. o–q, Lateral view of the same photoconverted embryo at 2 dpf, showing non-photoconverted Kaede (o), photoconverted Kaede specifically in somite 4 (p), and a merged image (q). Somites 2–6 are numbered. Scale bars, 100 μm (b–g, i–q), 50 μm (h–k).