HARP Enzyme (2 of 2) (IMAGE) University of California - San Diego Caption [...] in DNA "bubbles" that prevent critical genes from being expressed. Credit James Kadonaga, UCSD 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.