Alligators may help scientists learn how to stimulate tooth regeneration in people, according to new research led by the Keck School of Medicine of the University of Southern California (USC).
For the first time, a global team of researchers led by USC pathology Professor Cheng-Ming Chuong, M.D., Ph.D., has uncovered unique cellular and molecular mechanisms behind tooth renewal in American alligators. Their study, titled "Specialized stem cell niche enables repetitive renewal of alligator teeth," appears in Proceedings of the National Academy of Sciences, the official journal of the United States National Academy of Sciences.
"Humans naturally only have two sets of teethbaby teeth and adult teeth," said Chuong. "Ultimately, we want to identify stem cells that can be used as a resource to stimulate tooth renewal in adult humans who have lost teeth. But, to do that, we must first understand how they renew in other animals and why they stop in people."
Whereas most vertebrates can replace teeth throughout their lives, human teeth are naturally replaced only once, despite the lingering presence of a band of epithelial tissue called the dental lamina, which is crucial to tooth development. Because alligators have well-organized teeth with similar form and structure as mammalian teeth and are capable of lifelong tooth renewal, the authors reasoned that they might serve as models for mammalian tooth replacement.
"Alligator teeth are implanted in sockets of the dental bone, like human teeth," said Ping Wu, Ph.D., assistant professor of pathology at the Keck School of Medicine and first author of the study. "They have 80 teeth, each of which can be replaced up to 50 times over their lifetime, making them the ideal model for comparison to human teeth."
Using microscopic imaging techniques, the researchers found that each alligator tooth is a complex unit of three componentsa functional tooth, a replacement tooth, and t
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University of Southern California - Health Sciences