Figure 5.

Distribution of connexin43. A – Immunostaining of ventricular sections showed localization of connexin43 (Cx43) with intense staining plaques at the intercalated discs in WT mice. In Cap2^gt/+ the Cx43 signal was still present at the intercalated discs but showed the first signs of lateralization. Marked maldistribution and lateralization of the punctuate Cx43 signal were present in Cap2^gt/gt (arrowheads). Co-staining with phalloidin revealed that F-actin assembly in the cardiomyocytes was severely disturbed. Green = phalloidin, red = Cx43, bar = 20 μm. B – Semiquantitative real-time PCR analysis revealed up-regulation of Cx43 in the mutant mice, which was predominantly due to alterations in the left ventricle. C – Western blots of Cx43 showed no quantitative differences in ventricular protein concentrations between the groups. Arrows indicate the phosphorylated Cx43 bands. There was no evidence of relevant non-phosphorylated Cx43 accumulation in any group. D – A marked increase in lateralized Cx43 distribution was present in Cap2^gt/gt and, with weaker expression, in Cap2^gt/+ in comparison to WT

LV – left ventricle, RV – right ventricle, *p < 0.05 compared to WT. n = 5 per group.