This movie shows the growth, interaction, and movement of microtubule asters (in green) in Xenopus (frog) egg cytoplasm, following exit from metaphase (cell division). Asters grown in a thin layer of cytoplasm between two glass coverslips recapitulates the behavior of asters in early dividing live embryos during anaphase/telophase/cytokinesis.  Where asters meet, cytokinesis proteins such as the chromosomal passenger complex (visualized using a fluorescently labeled antibody against a CPC component, shown in red) are recruited. This establishes a boundary between the two asters, and marks the position of the putative cleavage furrow.