Fig. 3. Modeling RASopathy disease with BRAF^(V600E) overexpression using IQ-Switch.

a While a low dose of Teb (2.5 µM) was used to treat the genetic cross of Tg(ubb:QFDBD-2xAD*-VP16*-EcR,α-cry:EGFP) and Tg(5xQUAS:ZsGreen-P2A-BRAF^V600E,α-cry:mCherry) from 36 hpf to 60 hpf, 15 µM of vemurafenib was added to the transgenic embryos for an extended period from 36 hpf to 72 hpf. The live embryos were observed under an epifluorescence microscope at 72 hpf. The chemical structure of vemurafenib is shown below. b–u While green fluorescence in the lens manifested the existence of a driver cassette, mCherry in the lens represented an effector 5xQUAS:ZsGreen-P2A-BRAF^V600E transgene in the genome. b–f DMSO vehicle treatment. g–k Treatment with 15 µM of vemurafenib alone. l–p Treatment with 2.5 µM of Teb alone. The embryos showed ZsGreen reporter expression in whole tissues. q–u A representative image of embryos exposed simultaneously to both Teb (2.5 µM) and vemurafenib (15 µM). Similar to that of Teb alone, green fluorescence was detected in all tissues. v Embryos were classified into three groups following embryonic malformation. w A graphical view of the embryonic defects as in (v). n represents the number of embryos analyzed. Abbreviations: Teb; tebufenozide, Vem; vemurafenib. Scale bar; 150 μm.