Which came first .... the chicken, or the egg? The philosophical mystery that has perplexed generations has finally been "cracked" by scientists from Sheffield University and the University of Warick. The researchers have discovered that a protein required for the formation of the chicken egg shells is found in only one place - inside the ovaries of the chicken.

The protein, called ovocledidin-17, or OC-17, converts calcium carbonate into calcite crystals - acting as a catalyst to speed up the development and hardening of the shell, which is essential to protecting the yolk while the chick develops inside.

Dr. Colin Freeman, from Sheffield University's Department of Engineering Materials, said: "It had long been suspected that the egg came first but now we have the scientific proof that shows that in fact the chicken came first. The protein had been identified before and it was linked to egg formation but by examining it closely we have been able to see how it controls the process.

It's very interesting to find that different types of avian species seem to have a variation of the protein that does the same job."

The research was published earlier this month in the paper; Structural Control Of Crystal Nuclei By An Eggshell Protein.

Professor John Harding, from the same department, said the discovery could have other uses; "Understanding how chickens make egg shells is fascinating in itself but can also give clues towards designing new materials and processes - nature has found innovative solutions that work for all kinds of problems in materials science and technology - we can learn a lot from them."

Source: Daily Mail, UK