How chickens of a particular breed ensure that their necks remain feather free — an adaptation to hot weather — has been explained.


Denis Headon at the University of Edinburgh, UK, and his co-workers found that naked neck chickens (pictured) have a mutation that boosts levels of the protein BMP12. Adding this protein to neck skin tissue cultures from normal chickens blocked feather formation, although the treatment had little effect on skin cultures from other parts of the body. The skin on chickens' necks naturally contains high levels of a signalling molecule called retinoic acid. This, the researchers show, primes neck skin cells to respond to the extra BMP12 made by naked neck chickens, preventing feather growth.

PLoS Biol. 9, e1001028 (2011)