Fig. 7. At the first mitosis the nuclear membrane becomes permeable to high molecular weight molecules before the first Ca²⁺ transient is generated. FITC-dextran was injected into one of the pronuclei to monitor the permeability of the nuclear membrane in relation to the Ca²⁺ transient at NEBD. Ca²⁺ was monitored simultaneously using fura red. Nuclear FITC-dextran is shown in the top row and fura red images are shown in the bottom row. Note that the pronuclei can be seen in the fura red images because of fluorescence bleed-through from the FITC emission to the fura red emission collected using a 600 long-pass filter. Fluorescence traces of the FITC-dextran and fura red ratio are shown. The time scale in the images corresponds to that in the traces. Note the Ca²⁺ transient takes place after the nuclear fluorescence has started to decrease (n=24). See text for details.

Return to article