Putting the Squeeze on Sperm DNA (image) European Molecular Biology Laboratory Caption In the center, a structural model determined by X-ray crystallography shows how the two tags (attached to a short section of the histone protein -- all in cyan) fit neatly into the Brdt pocket (purple). In the background image, hypercompaction by Brdt causes relatively diffuse chromatin (stained blue inside the nuclei of two cells on the top left) to compact and clump together (two on the bottom right). Credit EMBL/IBS Usage Restrictions Policy regarding use EMBL press and picture releases including photographs, graphics, movies and videos are copyrighted by EMBL. They may be freely reprinted and distributed for non-commercial use via print, broadcast and electronic media, provided that proper attribution to authors, photographers and designers is made. High-resolution copies of the images can be downloaded from the EMBL web site: www.embl.org 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.