In birds, hormones may not be the last word in determining males and females
On rare occasions chickens don’t cross the road; they get stuck right in the middle, between male and female. A new study of these odd birds sheds light on the developmental processes that determine sex.
Contrary to an old view of sexual development, Michael Clinton and his colleagues at the Roslin Institute in Edinburgh say in the March 11 Nature, individual chicken cells can maintain their own strong male or female identities during development instead of being directed by hormones.
Clinton says his research group ended up considering hormones and sexual identity in the course of studying three