Fig. S4

Exogenous zCNTF induces expression of preconditioning genes and activates the epicardium. (a) Experimental design to assess effects of a single pericardial injection of zCNTF on gene expression and the epicardium. (b) In-situ hybridization of ventricular sections with different probes at 1 day post-injection (1 dpi) of control proteins (hIgG) and zCNTF. Several candidate genes identified in transcriptomic analysis are upregulated on the heart surface on the next day following zCNTF injection. n ≥ 3 hearts, 3 sections per heart each. (c) Immunofluorescence staining of ventricular sections of the transgenic fish ET27:EGFP (green) with antibodies against cardiac Tropomyosin (TPM, blue). At 0 dpt, ET27:EGFP+ cells are confined to the epicardium. At 7 dpi, ET27:EGFP+ cells expand and infiltrate the myocardium (arrows). (d) Quantification of intramyocardial ET27:EGFP+ area per ventricular section area. Superficial epicardial ET27+ cells were not included in measurements. n ≥ 3 hearts, 3 sections per heart each. *** P<0.001with student’s t-test.