Characterization of congenital vascular and intracardiac defects in the Ts65Dn murine model for Down syndrome
The Ts65Dn mouse is the most-studied murine model for Down syndrome (DS) or trisomy 21. Homology between triplicated murine genes and genes on human chromosome 21 (Hsa21) correlates with the shared anomalies of Ts65Dn mice and DS patients. Congenital heart defects occur in approximately 50 percent of DS individuals and we have worked to characterize cardiovascular anomalies observed in Ts65Dn neonates from seven complete litters. Vascular abnormalities were identified in 17 percent of trisomic neonates by examination of gross anatomy. We found right aortic arch with Kommerellnulls diverticulum, aberrant right subclavian and persistent truncus arteriosis. Intracardiac defects were detected using staining with hemotoxylin and eosin, and Masson’s trichrome. We have identified interventricular sepal defects and broad foramen ovale in trisomic neonates. Additionally, immunohistochemistry indicates abnormal muscle composition in the cardiac valves of trisomic neonates. These findings suggest that the gene imbalance in Ts65Dn disrupts crucial pathways in cardiac development.
Franklin and Marshall College Archives, Undergraduate Honors Thesis 2007
- F&M Theses Collection