In this movie clip, chromosomes in a C. elegans worm look like they're dancing as the cells start to undergo meiosis. Each cell contains a mix of chromosomes (red) from the mother and the father that need to match up before the cell can divide into sperm or eggs. The green areas show where chromosomes have latched on to the nuclear wall. The cell's cytoskeleton then leads them around the nuclear dance floor until each mom chromosome meets its dad equivalent. When they do, they clasp themselves together and swap a set of genes. Then they part once more. Courtesy of the Dernburg lab, University of California, Berkeley.