Mosaic Mouse (IMAGE) University of Pennsylvania School of Medicine Caption Epigenetic mosaicism occurs during mouse development in a mouse model of epigenetic disease. Credit Connie Jiang, M.D./Ph.D., student, Perelman School of Medicine, University of Pennsylvania. 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.