The Three Pharingos (image) University of Maryland Share Print E-Mail Caption This image of three worms illustrates functional mosaicism in action. The worms have been genetically modified to express a fluorescent protein that appears as colorful glowing dots. The worm on the left shows fluorescence in every cell. In the middle worm, intestinal cells do not fluoresce because a protein that blocks the fluorescent gene has caused RNA interference (RNAi). In the worm on the right, scientists have removed the enzyme previously believed to be responsible for RNAi in intestinal cells, but fluorescence remains blocked in some of those cells, suggesting that RNAi is being carried out by another enzyme. Credit Snusha Ravikumar/University of Maryland Usage Restrictions None Share Print E-Mail 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.