Atrial Identity Is Determined by A COUP-TFII Regulatory Network (RNA)

Atria and ventricles exhibit distinct molecular profiles that produce structural and functional differences between the two cardiac compartments. However, factors that determine these differences remain largely undefined. Cardiomyocyte-specific COUP- TFII ablation produces ventricularized atria that exhibit ventricle-like action potentials, increased cardiomyocyte size, and development of extensive T-tubules. We used microarrays to examine the molecular profile of cardiomyocyte-specific COUP-TFII knockout adult atria in comparison with that of normal atria. We extracted RNA from mutant right atria, control right atria and control ventricles from 2 months old adult mice, followed by gene expression profiling using Affymetrix microarrays.