Scientists solve chicken puzzle

The research, which involved studying rare naturally occurring chickens with white (male) plumage on one side and brown (female) plumage on the other, sheds new light on the sexual development of birds. It was previously thought that sex chromosomes in birds control whether a testis or ovary forms, with sexual traits then being determined by hormones. The findings, which are scientifically revolutionary in the field, may also be relevant to why males and females differ in behaviour and in susceptibility to disease. They could also lead to improvements in poultry production, as identification of some of the molecular differences between male and female cells should lead to better tests for sexing embryos prior to hatch. It might even be possible to devise ways of obtaining the growth characteristics of male birds in females, with improvements in feed efficiency and productivity that could contribute to future food security. This research has completely overturned what we previously thought about how sexual characteristics were determined in birds. Our study opens a new avenue for our understanding of birds? sexual development.