Fig.2. Electrostatic Repulsion (IMAGE) Osaka University Caption Without Mg<sup>2+</sup> ions, the negatively charged nucleosome fiber is stretched by electrostatic repulsion (left). Mg<sup>2+</sup> can eliminate the repulsion and promote nucleosome-nucleosome binding (center) and subsequent chromosome condensation. Credit National Institute of Genetics & Osaka University Usage Restrictions None 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.