Fig. 3

YAP1-MAMLD1 fusion drives tumor formation in vivo. a–h Immunofluorescence micrographs of supratentorial brain regions stained for EGFP a, c or Ki67 b, d from 7-day-old mice subjected to electroporation with YAP1-MAMLD1 or mock (EGFP alone) constructs. Insets in c represents electroporated cells positive for Ki67. Representative images of double staining for e YAP1/EGFP or f YAP1/DAPI and g p-YAP1/EGFP or h p-YAP1/DAPI in cells expressing the YAP1-MAMLD1 fusion gene. Arrows in d indicate abnormally proliferating cells. Arrowheads in e, f and in g, h indicate the same area, respectively (scale bar in d, 400 µm for a–d and 100 µm for inset; the bars in h, 25 µm for e–h). CP cortical plate, VZ ventricular zone. i, j Luciferase-based (i) in vivo bioluminescence images and j relative changes of luminescence at weeks 1–3 after birth of animals electroporated with indicated constructs. Error bars in (j) indicate mean ± S.D. k Kaplan–Meier curves for animals electroporated with the YAP1-MAMLD1-HA (cyan, n = 26, median survival = 35.5 days), C11orf95-RELA-HA (red, n = 6, median survival = 45 days) or indicated controls (n = 6 for YAP1-HA, n = 5 for MAMLD1-HA, n = 6 for YAP1ΔC-HA, n = 8 for YAP1(S127A)-HA, n = 6 for YAP1-MAMLDΔNLS-HA, n = 8 for YAP1-FAM118B-HA). l Immunofluorescence micrograph of a resected 21-day-old mouse brain electroporated with YAP1-MAMLD1 IRES-EGFP with the T2TP transposase. EGFP-positive cells have broadly spread into both the left (LH) and right (RH) hemispheres (OB olfactory bulb, CB cerebellum). m H&E staining of YAP1-MAMLD1-driven tumor indicated by a dotted line. CB cerebellum. Scale bar, 1 mm. n–v Double staining of cells derived from YAP1-MAMLD1-induced tumors with indicated antibodies and DAPI (scale bar, 100 µm)