Time course of the appearance of the
GFP–KDEL-labeled clusters in the vegetal cortex during maturation. In
this experiment, several oocytes were kept in individual dishes; at the
various time points, individual oocytes were transferred to the
microscope stage for imaging. The images shown were from the same
oocyte. The time after addition of progesterone is indicated on the
panels. The appearance of the white spot, caused by GVBD, was clearly
seen in this oocyte first at 11 h. The image sequence shows
the appearance of small clusters at around the time of GVBD, their
disappearance at an intermediate time, and then the appearance of large
clusters after the egg has become mature. Bar, 10 μm. Each graph
shows the time course of the abundance of clusters for three different
oocytes during maturation. Cluster abundance was scored visually on a
scale between no clusters (0) and maximum number of clusters (1.0). The
x-axis shows time after addition of progesterone. The
graphs for the different oocytes were positioned so that the decrease
in clusters is lined up. The middle panel corresponds to the image
sequence.