(IMAGE) Université de Genève Caption A transient change in expression of one gene (Shh) can produce a cascade of developmental events leading to the formation of feathers instead of scales. Credit © UNIGE / Cooper & Milinkovitch Usage Restrictions none License Original 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.