Smurf phenotype (IMAGE) University of Tokyo Caption Researchers track the intestinal health of fruit flies with a blue dye, hence the name Smurf. Fruit fly intestines damaged by aging leak the blue dye, this image shows an HRJD-modified fly on the left and an unmodified fly of the same age on the right. Credit ©2024 Hiroki Nagai CC-BY-ND Usage Restrictions Credit must be given to the creator. No derivatives or adaptations of the work are permitted. License CC BY-ND 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.