Fig 4. Loss of Ezh2 does not extend the neonatal regenerative time window.

(A) Masson’s trichrome-stained sections showing cardiac fibrosis at the level of the ligature (stitch) and below the ligature in control (Ezh2^fl/fl) and mutant (Ezh2^fl/fl;Myh6-Cre) hearts, 3 weeks post-MI induced at P7. Scar area is outlined. Plots represent the quantification of fibrotic scar area as a percentage of the left ventricle area. (B) Masson’s trichrome-stained sections showing fibrous tissue (blue) at the resection area in hearts 3 weeks post-resection induced at P7. Plots represent quantifications of scar area. Scar area is outlined. Scale bar = 500 μm.