Figure 7. Impaired Localization of β-Catenin and N-cadherin in B^ΔB1NC⁻/B^ΔB1NC⁻ Intercalated Discs.

(A) Immunofluorescence confocal images of adult heart sections from B⁺C⁺/B⁺C⁺, B^ΔB1NC⁻/B^ΔB1NC⁻, B^ΔB1NC⁺/B^ΔB1NC⁺, and B⁺C⁻/B⁺C⁻ mice stained for β-catenin (red, a–d), connexin43 (green, a–d) and N-cadherin (red, e,f). In contrast to B⁺C⁺/B⁺C⁺ (a,e), B⁺C⁻/B⁺C⁻ (d), and B^ΔB1NC⁺/B^ΔB1NC⁺ (c) cardiac myocytes where β-catenin and N-cadherin very precisely stain the intercalated discs, B^ΔB1NC⁻/B^ΔB1NC⁻ myocytes (arrows, b,f) show a diffuse β-catenin and N-cadherin staining. No difference in connexin43 staining (green, a–d) is observed among these four genotypes. Nuclei were stained by DAPI (blue). (B) Profiles of β-catenin staining at the intercalated discs for B⁺C⁺/B⁺C⁺ (red lines) and B^ΔB1NC⁻/B^ΔB1NC⁻ (black lines) mouse hearts. B^ΔB1NC⁻/B^ΔB1NC⁻ hearts showed a diffuse β-catenin distribution manifested by widened β-catenin staining at the intercalated discs compared to the wild-type hearts. An embedded Zeiss LSM image profile tool is used to quantify the fluorescence intensity along a line drawn vertically across the intercalated discs. Reproduced from reference 20.