Rat/Mouse Chimera (IMAGE) Cell Press Caption This photograph shows a 1-year-old chimera generated by injecting rat pluripotent stem cells (PSCs) into mouse blastocyst. Brown coat color indicates rat contribution. Credit Courtesy of Juan Carlos Izpisua Belmonte Usage Restrictions Credit Required. 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.