Emeritus Professor Susan Suarez

In the mouse, the female ovulates about 20 eggs into the oviduct.

In the mouse, the female ovulates about 20 eggs into the oviduct.

And the 20 eggs are surrounded by a cloud of cells called the cumulus, just like the cloud.

And the 20 eggs are surrounded by a cloud of cells called the cumulus, just like the cloud.

So when a sperm arrives on site, it's got to find an egg within this cloud.

So when a sperm arrives on site, it's got to find an egg within this cloud.

The first sperm to arrive at the cumulus cloud would fertilise the nearest egg inside.

The first sperm to arrive at the cumulus cloud would fertilise the nearest egg inside.

The second sperm would come in and bypass the nearest egg and go to the second nearest egg and fertilise that.

The second sperm would come in and bypass the nearest egg and go to the second nearest egg and fertilise that.

And the third sperm would go to the third egg.

And the third sperm would go to the third egg.

Now, how did they know that the first egg was already fertilised and they shouldn't waste their time?

Now, how did they know that the first egg was already fertilised and they shouldn't waste their time?

That's a big mystery.

That's a big mystery.

saying there's a lot more signalling going on between the male and the female than we've ever dreamed of.

saying there's a lot more signalling going on between the male and the female than we've ever dreamed of.