Figure 8: Calfacilitin-MO lowers intracellular calcium in epiblast adjacent to a grafted Hensen’s node.

Embryos were loaded with the Ca²⁺ indicator Rhod-2 and electroporated with Calfacilitin MOs before grafting an organizer (Hensen’s node) onto the electroporated region (stippled circle at 0 h). An embryo is shown 0 (a,f), 2 (b,g), 3 (c,h), 4 (d,i) and 6.5 (e,j) hours after the graft, revealing progressive loss of calcium signal under the graft. The left panels show the Ca²⁺ signal (red) overlapped with the fluorescein (green) revealing the MO; the right panels reveal only the Ca²⁺ signal. (k) Quantification of the Ca²⁺ signal in the MO-electroporated epiblast adjacent to the node graft of the same embryo (measured in the area outlined by a circle in a, comprising 13,996 pixels) over time. Compare with Fig. 6e for node graft without MO-electroporation). Scale bar (a–j), 100 μm.