Extended Data Figure 2 : ‘Tunable’ drug-inducible gene expression with LexPR and quantification of dose-dependent response to FGF signalling.

From: Luminal signalling links cell communication to tissue architecture during organogenesis

Extended Data Figure 2

a, Schema shows transactivator LexPR expressed under the control of CXCR4b promoter (Cxcr4b:LexPR) driving expression of LexOP-coupled coding sequences upon addition of inducer RU486 (above). Image of cxcr4b:LexPR-driven expression of lexOP:nlsGFP showing spatially restricted expression upon RU486 treatment. Scale bar, 500 μm (cry:eCFP ‘crystal eye’ marker: orange arrow; clmc2:GFP ‘bleeding heart’ marker: white arrow). b, Mean fluorescence intensity projection of Cxcr4b:LexPR, LexOP:nlsGFP primordium treated with 5 (n = 44), 10 (n = 34) and 20 μM (n = 32) RU486. Scale bar, 50 μm. Plot shows quantification of signal intensity after 4 h of RU486 induction (P5–10 = 2.53 × 10−8, P10–20 = 4.03 × 10−8). c, Colorimetric in situ hybridization of fgf3 mRNA in Cxcr4b:LexPR, LexOP:Fgf3–GFP showing uniform expression. Scale bar, 50 μm. d, e, Organ spacing in FGF inhibitor- and inducer-treated embryos at 2 d.p.f. d, Quantification of organ spacing (n = 78, 71, 74, Pctrl-05 = 6.22 × 10−14, P05-1 = 7.26 × 10−4) in SU5402-treated samples. e, Quantification of organ spacing (n = 109, 112, 119, 137, Pctrl-5 = 1.33 × 10−10, P5–10 = 7.06 × 10−4, P10–20 = 2.46 × 10−4) in RU486-treated samples. f, Organ depositions in WT and homozygous fgfr1at3R705H mutants shown by kymographs of 21 h time-lapse movies. Quantification of spacing (n = 49, 39, P = 7.69 × 10−14) and deposition timing (n = 31, 28, P = 4.64 × 10−11) between organs (first interval). Scale bar, 200 µm, 5 h.