An Organizing Force (IMAGE) Rockefeller University Caption During cell division, the mitotic spindle divides up duplicate DNA for the two future daughter cells. The researchers found that the motor protein kinesin-5 (green) helps prepare the spindle by organizing its filaments, or microtubules, (red) by pushing them or acting as a brake. Credit The Laboratory of Chemistry and Cell Biology Usage Restrictions Image may only be used to illustrate the research described in the accompanying release. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.