Muscular Blocker (IMAGE) University of Iowa Caption UI researchers have identified a key protein involved in muscle atrophy. The protein, Gadd45a, reprograms hundreds of genes inside a muscle cell's nucleus, causing the nucleus to dramatically change from a cigar shape (top) to a swollen bulb (bottom). Credit Adams lab, University of Iowa 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.