Finding the Gene for a Female Attack
Seachrist, Lisa, Science News
For more than 40 years, scientists have known that men and women are not created equal--immunologically speaking, that is.
Whether one views it as females attacking males or as a biological favoritism toward men, the fact is that men's bodies accept donor organs from women while women's bodies reject organs from men. Scientists speculated that a male specific antigen--a protein that exists in all cells of a man's body, but in none of a woman's--caused this incompatibility.
Over the years, however, this putative protein--designated the H-Y antigen--remained elusive. A team of researchers from Britain, the United States, and France now reports finding the gene for it on the Y chromosome. "The finding allows us to examine for the first time this male-female difference," says study collaborator Colin E. Bishop at Baylor College of Medicine in Houston.
Scientists first found evidence for the H-Y antigen when they transplanted skin between members of a highly inbred strain of laboratory mice. Apart from every males' distinctive Y chromosome, mice of both sexes were genetically identical. Males accepted transplanted skin from both males and females, but the females' immune systems slowly geared up to reject transplants from males.
Except for identical twins, humans aren't genetic duplicates so physicians prescribe drugs to stop any tissue differences from causing rejection. As a result, women's bodies accept donor organs from men. …