Female Chromosome Has X Factor

Females are genetically more varied than males, an analysis of the X chromosome has revealed. A large team of scientists has published a detailed profile of the DNA bundle in Nature magazine. They found that female mammals, who possess two copies of the X chromosome, express more genes than males, who only have one X and a Y chromosome. They also said that females were protected from many diseases because of their double dose of the X chromosome. "The X chromosome is the most extraordinary in the human genome in terms of biology and its association with disease," said Mark Ross, the project leader at the Wellcome Trust Sanger Institute, UK.