Figure 1
From: Mechanism of the chromosome-induced polar body extrusion in mouse eggs
Differential induction of cortical polarity and spindle formation by chromatin. (A-C) DNA bead-induced an actin cap (A, red, arrowhead) and a myosin II ring (B, green, arrowhead) which are comparable to those induced by maternal chromosomes (indicated by MII, A-C, arrows). (D-F) DNA bead-induced cortical actin cap (shown in red) and cortical granule (CG) redistribution (shown in white). Note that the injected DNA beads induced formation of a CG free domain (E, arrowhead), which is overlapping with the actin cap (D and E, arrowhead). The arrows point to the MII chromosome region. DNA is shown in blue in all the figures unless otherwise stated. (G) A bipolar spindle induced by the injected DNA beads. In this image, the microtubules are shown in green. (H) A DIC image of G showing the DNA beads. (I) A comparison of the time required for the cortical actin cap and spindle formation induced by DNA beads. The scale bars shown in all of the figures represent 20 μm unless otherwise stated.