FIGURE 7.

Proposed model of how endocardial Jarid2 expression regulates myocardial development. A, in the wild type mouse at later stages of development, Jarid2 represses Notch1 by binding to the Notch1 +1150-bp locus. Notch1 signaling to the myocardium ceases, and there is a decrease in trabecular proliferation and normal terminal differentiation. B, in the Jarid2 KO mouse at later stages of development, Jarid2 does not bind to the +1150-bp Notch1 locus, and Notch1 remains active. The prolonged activation of the Notch1 pathway results in increased trabecular proliferation and defective terminal differentiation.