The Chicken May Have Come Before The Egg

The age old question of “Which came first, the chicken or the egg?”, has been tentatively answered. The verdict? The chicken, or rather a key protein needed to form the shell of the egg. The protein, called ovocledidin-17, was known to be involved in binding calcite molecules that formed the shells, but the mechanism behind this was unclear until now (abstract). The protein acts as a molecular machine, binding two nanoparticles of calcite and guiding them to begin self-assembly of the shell. This gives tremendous insight for developing methods of nano-scale self-assembly based on natural processes, as well as settling heated cocktail party arguments everywhere.

British researchers may have uncovered a partial answer to the age-old question, “what came first the chicken or the egg?”. According to a team, comprising researchers from the University of Warwick and the University of Sheffield, the answer is “chicken” or at least a particular chicken protein.

There is, however, a further twist – this particular chicken protein turns out to come both first and last. That neat trick it performs provides new insights into control of crystal growth which is key to egg shell production.

Scientists have long believed that a chicken eggshell protein called ovocledidin-17 (OC-17) must play some role in egg shell formation. The protein is found only in the mineral region of the egg (the hard part of the shell) and lab bench results showed that it appeared to influence the transformation of (CaCo3) into calcite crystals. The mechanism of this control remained unclear. How this process could be used to form an actual eggshell remained unclear.