Researchers conclude chicken comes before an egg

Researchers at the Universities of Sheffield and Warwick have gained a significant new insight into egg shell formation and come up with a partial answer to the age-old question “which came first, the chicken or the egg?”

The researchers found that “chicken”, or at least a particular chicken protein found in the ovaries of hens, comes first in this context.

“Researchers had long known that a chicken protein called ovocledidin-17 (OC-17) must play some role in egg shell formation,” said a university spokesman.

The protein is also found in the the hard part of the shell and appears to influence the transformation of calcium carbonate into calcite crystals – the first stage of egg formation.

Using a powerful computing tool called metadynamics, along with the national supercomputer in Edinburgh, the researchers were able to create simulations that showed exactly how the OC-17 protein binds to the calcium carbonate.

Effectively it acts as a catalyst, clamping on to the calcium carbonate particles to kickstart crystal formation and then dropping off when the crystal nucleus is sufficiently large to grow under its own steam. This frees up the OC-17 to promote yet more crystallisation, facilitating the speedy, overnight creation of an egg shell.

The story has provided the media with a field day for “chicken and egg” stories, with over 100 related news items on the subject listed on Google on Wednesday (14 July) alone.

Lead researcher Dr Colin Freeman is quoted as saying the findings provide “scientific proof” that the chicken came first. “You don’t get the chicken egg unless you have the chicken,” he told the ABC news agency.

* Watch out tonight (Thursday) for Jimmy Doherty’s show The Secret Life of….chickens on BBC2 at 8.00pm and share your views on our Chicken Chat forum