SCientists Explain Why There are Half Male/Female Chickens

March 11th, 2010

Yup…this is what I am going to talk about. Hermaphrodite chickens. Well…not so much that weird, but scientists have puzzled for hundreds of years why some chickens seem to appear male one one side, and female on the other. This important mystery has been solved according to Science Daily.

Let’s be frank here. Neither you, nor I even knew this was a real thing until just now, but science of the odd is always worth a bit more of a read yes? Of course.

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. Oh no…not the case my friends.

The researchers, however, identified differences between male and female cells that control the development of sexual traits. The scientists have named the phenomenon, cell autonomous sex identity (CASI).

The study from The Roslin Institute at the University of Edinburgh, which receives key funding from the Biotechnology and Biological Sciences Research Council, is published in the journal Nature. You can find them on the net if you ever took advantage of laptop deals.

Dr Michael Clinton, who led the study, said: “This research has completely overturned what we previously thought about how sexual characteristics were determined in birds. We now believe that the major factors determining sexual development are built into male and female cells and derive from basic differences in how sex chromosome genes are expressed. Our study opens a new avenue for our understanding of sexual development in birds.

“It also means we must now reassess how this developmental process occurs in other organisms. There is already some evidence that organs such as the heart and brain are intrinsically different in males and females and birds may provide a model for understanding the molecular basis for these gender differences.”