Sexual separation does not depend on hormones in hens

2010/03/11 Lakar Iraizoz, Oihane - Elhuyar Zientzia

• Zoologia

In chickens sexual differentiation is not done at the individual level but at the cellular level. To this conclusion researchers from the University of Edinburgh have arrived, who have studied some special chickens/roosters that are half and half, rooster individuals.

In mammals, sex hormones guide the sexual differentiation of the whole individual, and until these hormones occur the cells do not begin to develop or the characteristics of females. Until now it was thought that birds had the same mechanism, but this research has shown that no, that in birds every cell knows from the beginning, based on their chromosomes, whether it is female or male.

Thus, in these special hens analyzed it has been observed that there was no chromosomal abnormality, that is, in the area of the females the normal female cells predominated and in that of the males the normal male cells.

In addition, the embryos of normal hens were subsequently analyzed and what was observed in hybrids was confirmed. In fact, they saw that embryonic cells of only 18 hours had begun to appear sex-specific molecules. And in the development of embryos sex hormones begin to appear much later.

Photos: Photos University of Edinburgh Roslin Institute