Male Mice Created Without Y Chromosome
http://ts-si.org/genetics-&-genome/28187-male-mice-created-without-y-chromosome12/26/10
Scientists have activated an ancient brain gene to create male mice without a Y chromosome, a major step toward fuller understanding of overall human sexual development. Given the provably direct similarities and predictive qualities of the mouse model organism, and the existence of masculine XX humans, the findings provide a near-definitive reset of the Y chromosome's role in human sexual development.
Males usually have one Y chromosome and one X chromosome, while females have two X chromosomes. A single gene on the Y, called SRY, triggers testes development in the early embryo, and once these begin to form, the rest of the embryo also becomes male.
However, an international collaborative team at the University of Adelaide discovered a way of creating a male mouse without a Y chromosome by activating a single gene, called SOX3, in the developing fetus. They also showed for the first time that changes in the human version of the same gene are present in some patients with disorders of sexual development.
