Fig. 4

Cadherin is involved in unfit cell sensing. a, b Mosaic unfit abnormal Wnt/β-catenin-activity cell introduction changes exogenous E-cadherin levels in zebrafish embryos. Confocal images showing embryos injected with E-cadherin-GFP mRNA (green) and mosaically introduced with mKO2 alone-expressing control cells or mKO2 and β-catCA- or Axin1-overexpressing cells (magenta). Right panels show fluorescence intensity of E-cadherin-GFP. Scale bar, 50 μm. c, d Partial E-cadherin knockdown (c) or E-cadherin overexpression (d) blocks β-catCA- or Axin1-overexpressing cell apoptosis. Confocal images showing whole-mount immunostaining of active caspase-3 (magenta) in mosaic embryos expressing membrane GFP ± β-catCA or Axin1 (green) and injected with low dose E-cadherin MO (E-cad KD) or E-cadherin mRNA. Arrowheads indicate caspase-3-active cells. Scale bar, 50 μm. Graphs show the means ± SEM (n = 8 or more embryos, two independent experiments) of GFP⁺ (β-catCA, Axin1) caspase-3 active cell frequencies (right). **p < 0.01, *p < 0.05 (t test). e Cells with unfit high E-cadherin levels undergo apoptosis in mosaic embryos. Confocal images showing whole-mount immunostaining of active caspase-3 (magenta) in mosaic embryos expressing membrane GFP ± E-cadherin or its mutant (green). Arrowheads indicate caspase-3-active cells. Scale bar, 50 μm. Graphs show the means ± SEM (n = 5 or more embryos, two independent experiments) of GFP⁺ caspase-3-active cell frequencies (right). **p < 0.01 (t test). f Cells with unfit low E-cadherin levels undergo apoptosis in mosaic embryos. E-cadherin partial knockdown (E-cad KD) cells or control cells (magenta) were transplanted into wild-type embryos. Confocal images showing whole-mount immunostaining of active caspase-3 (green) in mosaic embryos. Arrowheads indicate caspase-3-active cells. Scale bar, 50 μm. Graph shows the means ± SEM (n = 7 or more embryos, two independent experiments) of GFP⁺ caspase-3-active cell frequencies (right). **p < 0.01 (t test). See also Supplementary Fig. 4