Fruit Flies (IMAGE) University of Veterinary Medicine -- Vienna Caption The Y-chromosome of fruit flies consists not just of "gene-junk", but also functioning genes. Credit Markus Riedl 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.