The Y Chromosome is Here to Stay with Stable Genes: Men are Not Disappearing

The male chromosome in humans, the Y chromosome, has had a history of dramatic genetic decay. Despite this, though, it's managed to preserve a small set of genes. Now, researchers have found that these genes ensure not only the chromosome's survival, but also the survival of men in general.

Over evolutionary history, the Y chromosome has continually lost genes. In fact, the human Y chromosome only retains 19 of the more than 600 genes it once shared with its ancestral partner, the X chromosome. Yet when the researchers recently compared the Y chromosome from humans to that of the chimpanzee and the rhesus macaque, they found that it had only lost one gene over the past 25 million years.

"This paper tells us that not only is the Y chromosome here to stay, but that we need to take it seriously, and not just in the reproductive tract," said David Page, one of the researchers, in a news release. "There are approximately a dozen genes conserved on the Y that are expressed in cells and tissue types throughout the body. These are genes involved in decoding and interpreting the entirety of the genome. How pervasive their effects are is a question we throw open to the field, and it's one we can no longer ignore."

In this latest study, the researchers mapped the evolution of the Y chromosome in the marmoset, the mouse, the rat, the bull and the opossum. They then compared the ancestral portions of these Y chromosomes and revealed a set of broadly expressed genes across all eight species. This shows a surprising amount of genetic stability.

"Evolution is telling us these genes are really important for survival," said Winston Bellott, one of the researchers, in a news release. "They've been selected and purified over time."

The findings reveal that the Y chromosome is crucial for survival. Currently, the scientists hope to answer what this set of Y genes is actually doing, since it's not yet clear. The research reveals that scientists need to move beyond a unisex model of biomedical research and instead take the Y chromosome into account.

The findings are published in the journal Nature.