The widely held scientific theory that the mammalian Y chromosome is slowly decaying or stagnating has been challenged by a new study.
It has suggested that the Y chromosome, found only in males, is actually evolving quite rapidly through continuous, wholesale renovation.
By conducting the first comprehensive interspecies comparison of Y chromosomes, Whitehead Institute researchers have found considerable differences in the genetic sequences of the human and chimpanzee Ys-an indication that these chromosomes have evolved more quickly than the rest of their respective genomes over the 6 million years since they emerged from a common ancestor.
"The region of the Y that is evolving the fastest is the part that plays a role in sperm production," Jennifer Hughes, first author and a postdoctoral researcher in Whitehead Institute Director David Page's lab, said.
"The rest of the Y is evolving more like the rest of the genome, only a little bit faster," she added.
Researchers have found that chimp Y has lost one third to one half of the human Y chromosome genes.
Howard Hughes Medical Institute investigator David Page said that this is not all about gene decay or loss. He likens the Y chromosome changes to a home undergoing continual renovation.
"People are living in the house, but there's always some room that's being demolished and reconstructed. And this is not the norm for the genome as a whole," he said.
Wes Warren, Assistant Director of the Washington University Genome Center, agrees.
"This work clearly shows that the Y is pretty ingenious at using different tools than the rest of the genome to maintain diversity of genes," he said.
"These findings demonstrate that our knowledge of the Y chromosome is still advancing," he added.
The findings are published online this week in the journal Nature.