But it does this indirectly by preventing BMP from relaying its message to cells. In addition, the researchers find that Tsg and chordin, when present together, inhibit BMP more efficiently. Brivanlou's results in frogs have been replicated in fruit flies and zebra fish by researchers at the University of California at Irvine and at the University of Wisconsin. All three groups reported their findings in the March 22 issue of Nature. So far, five of these BMP inhibitors, also called antagonists, have been identified, including chordin, noggin and follistatin, the third of which was discovered by Brivanlou's lab in 1994.
Twisted gastrulation marks the sixth.
In addition, BMP and its inhibitors are important regulators of bone, cartilage and joint formation in adults, and thus may be used in the treatment of bone fractures or diseases associated with skeletal defects, like osteoporosis. Originally identified in the fruit fly Drosophila, Twisted gastrulation was named after mutant fruit flies lacking the gene, which appeared twisted while gastrulating. Gastrulation is a crucial stage of embryogenesis when the three germ layers begin to take shape and the primary body axes are constructed. It is at this time that cell fate is established. In order to determine whether Tsg could act as an antagonist of BMP, the researchers employed a classical embryology experiment called cell dissociation.