Fig. S7

Fig. S7 Cxcl12b directs coronary vessel formation. (Related to Figure 6)

Uniform over-expression of cxcl12b resulted in a reduction in vessels and endothelial/vessel density in adult fish. However, this measurable reduction in endothelial cell density on the surface of the ventricle was not observed in older adult zebrafish over-expressing cxcl12b (137dpf A and B; 173dpf C and D). Ectopic expression of cxcl12b in atrial cardiomyocytes is not sufficient to direct vessel development on the surface of the atrium (C′ and D′, intensity levels adjusted to allow visibility of weaker atrial expression levels). Clonal overexpression of Cxcl12b in cardiomyocytes results in a significant increase in vessel density over the expressing region (E-I). Cxcl12b expression is indicated by the loss of H2B-Cerulean in myl7:DsRed2-NLS-positive cardiomyocytes (E-G, demarked by orange outline). Increase in density was measured using threshold level to define and estimate fli1a:EGFP-positive pixels that were part of the vascular network (H and I) and comparing this density between cxcl12b-expressing and non-expressing regions (demarcated by orange in this example, F and G) within an induced heart (paired t-test) and with siblings which lacked the myl7:CreERt2 transgene (non-paired t-test). Scale bars, 50 µm.