Study: The human Y chromosome may be lost

STATE COLLEGE, Pa., July 16 (UPI) -- U.S. scientists say a rapid evolution of the Y chromosome carried only by men has led to a rapid gene loss that might lead to the chromosome's disappearance.

Pennsylvania State University Associate Professor Kateryna Makova, who led the study, and researcher Melissa Wilson compared the DNA of the X and Y chromosomes in different classes of mammals.

The researchers found that DNA of the human Y chromosome began to evolve rapidly 80 million to 130 million years ago. But while DNA on X chromosomes evolved at a constant rate, the rapid evolution of the Y chromosome has resulted in a rapid loss of genes.

"Today, the human Y chromosome contains less than 200 genes, while the human X chromosome contains around 1,100 genes," Wilson said.

"There is a chance that the Y chromosome eventually could disappear," Makova said. "If this happens, it won't be the end of males. Instead, a new pair of non-sex chromosomes likely will start on the path to becoming sex chromosomes."

The research appears in the journal PLoS Genetics.