Fig. 8.

Epicardial cryoinjury-induced expansion and activation are impaired in nrp1a^sa1485 mutants. (A-D) The apices of wild-type and nrp1a^sa1485 zebrafish ventricles were collected 5 days post sham surgery or cryoinjury and cultured on fibrin gels for 7 days. (A) Epicardial cells migrated into the fibrin gels (dotted black lines). (B) Epicardial outgrowths were measured for each condition (sh, sham-operated and CI, cryoinjured hearts) after 7 days culture. Data are mean outgrowth area (mm²)±s.e.m. ***P<0.001 (one-way ANOVA with Sidak's post hoc test for multiple comparisons of n>9). (C) Epicardial explant recovered from wild-type and nrp1a^sa1485 tg(wt1b:EGFP)^li1 cryoinjured fish at 5 dpci were left to grow on fibrin gels for 7 days and stained for GFP. GFP fluorescence was observed at 10× (left column) and 40× magnification at the center and the periphery of the explants (middle and right columns, respectively). (D) Cell size (left) and ploidy (right) were quantified both at the center (top row) and at the edge (bottom row) of the explant. Data are expressed as percentage of cells per field of view ±s.e.m. Each n represents an average of 3 fields of view per explant (two-tailed t-test of n≥5); *P<0.05. ns, not significant. Scale bars: 1 mm in A, 20 µm in C (right); 100 µm in C (left).