Fig. 8.

Cells expressing CD45 are scattered in the subepicardium of the interventricular sulci. Confocal microscopic images of sections from a 13 dpc heart stained with anti-CD45 (green) (b, g, l, r), anti-Flk1 (white) (c, h, m, s), anti-Fli1 (red) (d, i, n, t) antibodies; merged panels stained additionally with the Hoechst to depict cell nuclei (blue) (a, f, k, p, e, j, o, u). The subepicardial areas shown in white boxes of panels a, f, k, p are enlarged on panels e, j, o, u. Cells expressing CD45 phenotype are located outside blood islands in the subepicardium (red arrows) (j). Some of the CD45⁺ cells co-express the Fli1 transcription factor (marked with green arrows) (e, o, u). CD45⁺ and CD45/Fli1 double-positive cells are located in a close vicinity of Flk1⁺/Fli1⁺ cells (white arrows) (e, j, o, u). Scale bars 50 µm