Heterozygous deletion of β-catenin does not affect adult heart morphology, but attenuates the hypertrophic response. (A) Top row— hematoxylin and eosin (H&E)-stained paraffin-embedded sections; 400× magnification, scale bar—50 μm. Bottom row—Picrofuchsin van Gieson-stained paraffin-embedded sections; 100× magnification, scale bar—200 μm for H&E and 100× for van Gieson; WT/WT—control; WT/CKO—heterozygous. (B) Heart weight/tibia length (HW/TL) ratio in trained and untrained mice. WT/WT control, n = 11, WT/WT training n = 11, WT/CKO control, n = 7, WT/CKO training n = 12. (C) Cardiomyocytes cross-section area in trained and untrained mice. Over 100 cells per heart from 3 hearts of each genotype were analyzed. (D) Electrophysiological monitoring of heart rate (beat/min) in trained and untrained mice. WT/WT control, n = 5, WT/WT training, n = 4, WT/CKO control, n = 4, WT/CKO training n = 4. (E) qPCR analysis of fetal gene expression in control and trained WT/WT and CKO/WT mice. n = 5. The data are expressed as the mean ± SD of arbitrary fold of change relative to control levels. * p < 0.05, ** p < 0.01, *** p < 0.005 (Kruskal–Wallis test followed by Dunn’s multiple-comparison post hoc test).