Researchers reveal secret of the male chromosome

The secret of what makes men and what ensures their survival is revealed today by scientists who have decoded the hidden messages of the male Y chromosome.

A team of 40 researchers unravelled one of the least understood areas of the human genome to discover that the Y chromosome had a unique system of self-preservation.

Some scientists had suggested that the Y chromosome was "rotting" because it was not able to repair itself by swapping genetic material with another chromosome - it is the only chromosome in human cells that does not come as a pair.

This gave rise to speculation that the Y chromosome only had about five million years left in evolutionary terms before it degraded to such a level that it became functionally useless.

David Page of the Massachusetts Institute of Technology and his colleagues have discovered, though, that many of the male-only genes of the Y chromosome are duplicated so that they can swap genetic material between each other to correct defects.

The genes involved in the act of producing sperm were subjected in particular to these process of gene overwriting, said the MIT team, writing in the journal Nature, ensuring that genetic erosion did not undermine that critically important process.