JACC Clin Electrophysiol
September 2018
Birth Defects Res A Clin Mol Teratol
June 2011
Defects originating from the atrioventricular canal region are part of a wide spectrum of congenital cardiovascular malformations that frequently affect newborns. These defects include partial or complete atrioventricular septal defects, atrioventricular valve defects, and arrhythmias, such as atrioventricular re-entry tachycardia, atrioventricular nodal block, and ventricular preexcitation. Insight into the cellular origin of the atrioventricular canal myocardium and the molecular mechanisms that control its development will aid in the understanding of the etiology of the atrioventricular defects.
View Article and Find Full Text PDFRationale: The clinically important atrioventricular conduction axis is structurally complex and heterogeneous, and its molecular composition and developmental origin are uncertain.
Objective: To assess the molecular composition and 3D architecture of the atrioventricular conduction axis in the postnatal mouse heart and to define the developmental origin of its component parts.
Methods And Results: We generated an interactive 3D model of the atrioventricular junctions in the mouse heart using the patterns of expression of Tbx3, Hcn4, Cx40, Cx43, Cx45, and Nav1.
The T-box transcription factor Tbx2 plays important roles in patterning and development, and has been implicated in cell-cycle regulation and cancer. Conventional disruption of Tbx2 results in abnormalities of the heart, limbs, eye and other structures, and early fetal lethality. To gain insight into the role of Tbx2 in different tissues and at different stages of development, we have generated a conditional null allele of Tbx2 by flanking Exon 2 with loxP sites (Tbx2(fl2)).
View Article and Find Full Text PDFThe primary myocardium of the embryonic heart, including the atrioventricular canal and outflow tract, is essential for septation and valve formation. In the chamber-forming heart, the expression of the T-box transcription factor Tbx2 is restricted to the primary myocardium. To gain insight into the cellular contributions of the Tbx2+ primary myocardium to the components of the definitive heart, genetic lineage tracing was performed using a novel Tbx2Cre allele.
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