The male Y chromosome is more than a sex object. Yes, it has genes that, when paired with a female X chromosome, make a real man--genes for sex determination and sperm creation. But that’s beginning to look like a superficial view of this smallest, stubbiest of our chromosomes. The Y also seems to hold genetic keys that stave off cancer and add years to a man’s life, according to new research.
The study, published Monday in Nature Genetics, followed about 1100 Swedish men for more than 40 years. It showed that elderly men with some blood cells that had mutated and lost the Y also lost about 5 years from their lifespans, compared with men in the group who still had their Ys. Cancer was a particular affliction.
That would be an odd, somewhat puzzling result. Except that it comes on the heels of other research, published just last week in Nature, that showed the Y harbored what biologist and study coauthor David Page called 12 “elite” genes. These genes, he told Scientific American, have nothing to do with sex but everything to do with the proper functioning of cells throughout the body.
These genes synthesize proteins, help form connections between nerve cells, heighten the immune system’s ability to detect threats, and do many other things that keep us going. They are important enough, Pages noted, that they have been preserved on the Y for millions of years while most of the chromosome’s other genes have been whittled away. They are survivors, he believes, because they help us survive.
The Swedish study bolsters that view. The men ranged in age from their early 70s to early 80s. Those who suffered from cancer, and had an early demise, were prone to lose Y chromosomes in their white blood cells. (As cells replicate, mutations—errors in the replication process--sometimes rob them of genes or, in this case, entire chromosomes.) These blood cells are part of the immune system and normally help seek and destroy cancer cells, note Jan Dumanski and Lars Forsberg, researchers in Uppsala University’s Department of Immunology, Genetics and Pathology, who led the study. Without a Y and its hardy cargo of genes, these cells may fail in their mission, they and their colleagues suggest.
It is an intriguing bit of evidence that Page’s contention, that the Y carries an organism’s survival kit, may not be too far off the mark.