Structure and evolution of human Y chromosome DNA.

Two repeated sequences account for 70% of the DNA of the human Y chromosome. They are located in the heterochromatin of the long arm. These sequences are related to others found on human chimpanzee and gorilla autosomes, and on the human X chromosome but have diverged in a characteristic way from the non Y copies. They have no detectable phenotypic effect when translocated to autosomes. We have cloned DNA from the human Y chromosome using fluorescence activated cell sorting. At least one single copy sequence is present on both the X and Y chromosomes.