Fig. 2. E-cadherin localizes to the intercalated disc in the transgenic heart. Heart sections from 4-week-old animals were analyzed by indirect immunofluorescence for distribution of N-cadherin and E-cadherin. Endogenous N-cadherin was localized to the intercalated disc in wild-type heart (A). For comparison, a MHC/Ncad4 heart section was double-stained for chicken N-cadherin (B) and both mouse and chicken N-cadherin (C). No antibody was available that recognizes only mouse and not chicken; therefore, the staining patterns in (B) and (C) were identical in the transgenic heart, which was confirmed in the merged image (D). Chicken N-cadherin was located in the intercalated disc (B) similar to endogenous N-cadherin observed in wild-type (A). In addition, exogenous N-cadherin was distributed throughout the cytoplasm (B). In contrast, little cytoplasmic staining was observed for N-cadherin in wild-type heart (A). As expected, E-cadherin was absent from wild-type heart (E). A MHC/Ecad33 heart section was double-stained for E-cadherin (F) and N-cadherin (G) and merged (H) demonstrating the co-localization of these cadherin subtypes in the intercalated disc (arrows). Excess E-cadherin was observed in the cytoplasm. Bar, 25 µm.