FIGURE 5.

Notch1 and ErbB2/4 are elevated in Jarid2 KO hearts. A–H, immunostaining for Notch1 was performed on wild type and Jarid2 KO mice at both E10.5 (C and D) and E12.5 (G and H). The arrows indicate higher levels of Notch1 in the endocardium of Jarid2 KO mice (D and H) as compared with wild type mice (C and G). Hoechst staining was done to stain for nuclei (A, B, E, and F). I–L, immunostaining for ErbB2/4 was performed on Jarid2 KO (L) and wild type mice (K) at E15.5. Jarid2 KO mice display higher levels of ErbB2/4 in the myocardium versus wild type. Hoechst staining was performed to stain nuclei (I and J). M–P, Western blotting was performed on E14.5 wild type or Jarid2 KO hearts for N1ICD (M and N; n = 3) or ErbB4 (O and P; n = 5). Protein levels were standardized to β-actin. An asterisk indicates a significant difference when p values are less than 0.05 from a Student's paired t test, and error bars represent the standard error of the mean.