Professor Sykes discusses the number of genes on the y chromosome

Teacher:
You've talked about 27 genes on the y chromosome. How long ago were there more than 27 and what number was it?

Professor Sykes:
Well, we don't really know.

It's only this June that the paper was published which described exactly how many genes there were. You can see genes on the y chromosome that have very similar sequences to genes on the x chromosome but you can also tell by the y chromosome sequences that those genes don't actually work.

But when they packed up, I don't know. And we don't know because we don't really know enough about the y chromosomes of many different people. And work that will carry on now, I'm absolutely sure, will be to look (particularly amongst infertile men) about whether we can pick out which genes are not working and why they're not working and so on. And the end of that we'll probably know a lot more.