[Histopathological analysis of neonatal mouse hearts with connexin43 gene defects].

OBJECTIVE

To investigate the characteristics of heart morphology in neonatal mice with connexin43 gene defects.

METHODS

Two mouse lines were used in this study, which included connexin43 knockout (Cx43KO) mice and CMV43(CT) transgenic mice. PCR analysis was carried out to identify the genotypes of two transgenic mice. Sections with HE staining were analyzed to display the morphologic structures of the hearts in neonatal mice. C57BL6/SJ mice were used as control.

RESULTS

All 11 homozygous Cx43KO mice died within 24 hr after birth showing severe right ventricular outflow tract obstruction (RVOTO). Out of 20 homozygous CMV43(CT) transgenic mice, 12 mice died within 48 hr after birth showing not only RVOTO, but also atrial septal defect (ASD), ventricular septal defect (VSD) and other cardiac defects, while the remaining 8 mice were alive without heart defects. Both heterozygous Cx43KO and CMV43(CT) transgenic mice had normal hearts.

CONCLUSION

Connexin43 gene defect is obviously associated with abnormal heart morphogenesis. The different types and different dosage of the gene defects may lead to different phenotypes of hearts.