For years, Kathleen Gould, Ph.D., and her colleagues have drawn models of the contractile ring — the molecular apparatus that physically divides cells — and its parts. They used genetic studies to probe how the protein parts fit together, but their models involved some educated guesses. “We drew things certain ways, but we didn’t really know,” said Gould, professor of Cell and Developmental Biology. Now, they know. Using super-resolution microscopy tools available in the Nikon Center of Excellence, the investigators have determined the molecular architecture of the contractile ring in the fission yeast, Schizosaccharomyces pombe. Their findings, published in the journal eLife, provide a framework for understanding how the contractile ring forms and functions in cell division — a process that is essential for life.