Fig. 4

Preference for wwtr1 mutant cardiomyocytes to enter the trabecular layer in wild-type hearts. Confocal sagittal or transverse (WT→wwtr1^−/−) sections of mosaic hearts derived from transplanting wwtr1^+/− or wwtr1^−/− cells into wild-type hosts (A), and vice versa (B). Scale bars: 10 μm. (A′,B′) Proportion and number of donor cardiomyocytes contributing to the trabecular (green) or compact (purple) layers. Detailed quantification can be found in Fig. S6A,B. ***P<0.001 by exact Binomial test. (C) S79A substitution in Wwtr1 results in a constitutively active Wwtr1 protein (CAWwtr1). Peptide alignment of Wwtr1 to Yap1 surrounding the HXRXXS motif corresponding to S87 of Yap1. (C′) Confocal mid-sagittal sections of hearts from wild-type larvae injected with myl7:mKate (control) or myl7:mKate-2A-CAwwtr1 plasmids. Scale bars: 10 μm. (C″) Proportion and number of cardiomyocytes positive for mKate or CAWwtr1 found in the trabecular (green) or compact (purple) layers. Detailed quantification can be found in Fig. S6C. ***P<0.001 by exact Binomial test.