The human Y chromosome (IMAGE) University of California - Santa Cruz Caption Until recently, about half of the human Y chromosome was missing from the reference genome. Now, scientists have sequenced this chromosome from end to end. Credit National Human Genome Research Institution Usage Restrictions No restrictions. License Public Domain 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.