In a sense, all teeth can be considered wisdom teeth if their cells of origin are the determining factor. Scientists have developed a sophisticated genetic tracking system that allows them to follow the migration of cells as they stream from the embryonic mouse brain to the developing body, including the primordial jaw where they contribute to the formation of teeth and supporting structures. This is the first time a group of embryonic cells has been 'tagged" and followed throughout development to their final destiny. The research was a collaborative effort of several institutions, led by Dr. Yang Chai from the University of Southern California. The study, which appears in the March 21 issue of Development, was supported in part by the National Institute of Dental and Craniofacial Research.
"This technology allows us to closely follow an important group of cells that contribute not only to formation of the teeth and other craniofacial structures, but also to parts of the developing cardiovascular system," said Dr. Chai. "We will soon be able to look at animal models for a variety of human genetic disorders and observe in minute detail the effects on this key cell population. Likewise, we will be able to scrutinize corrective measures, such as gene therapy."
The cells shown by Chai and colleagues to be at the root of forming teeth, jaws, and other body parts are called neural crest, named for their site of origin. When the embryo is little more than an elongated blob, a thickened band of cells forms along the dorsal surface. This "neural plate" of cells is the future brain and spinal cord. Neural crest cells soon sprout from neural plate to form crescent-shaped bands along either side of the plate.
Traditional methods of labeling and staining cells indicate that neural crest cells leave the presumptive brain region of the embryo and migrate to distal sites of the emerging body. However, the labeling techniques have been rather imprecise unt
Contact: Wayne Little
NIH/National Institute of Dental and Craniofacial Research