Alligator’s smile provides tooth regeneration clues
12 Jun 2013 by Evoluted New Media
Scientists are studying alligators in order to potentially understand how to stimulate tooth regeneration in humans.
The global researcher team led by Keck School of Medicine of the USC has for the first time uncovered unique cellular and molecular mechanisms behind tooth renewal in American alligators.
“Humans naturally only have two sets of teeth – baby teeth and adult teeth,” said USC pathology Professor Cheng-Ming 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 their teeth. But, to do that, we must first understand how they renew in other animals and why they stop in people.”
Most vertebrates can replace teeth throughout their lives, but human teeth are naturally replaced only once. This is despite the lingering presence of the dental lamina, a band of epithelial tissue which is crucial to tooth development.
The researchers used microscopic imaging techniques to discover that each alligator tooth is a complex unit of three components – a functional tooth, a replacement tooth, and the dental lamina – in different developmental stages.
Each tooth unit is structured to enable a smooth transition from dislodgement of the mature tooth to replacement with the new tooth. The team suggest that alligator dental laminae contain stem cells which allow new teeth to develop.
“Stem cells divide more slowly than other cells. The cells in the alligator’s dental lamina behaved like we would expect stem cells to behave,” said co-author Randall B. Widelitz, Associate Professor of Pathology at the Keck School of Medicine.
“We hope to isolate those cells from the dental lamina to see whether we can use them to regenerate teeth in the lab.” The team also discovered the novel cellular mechanism by which the tooth unit develops in the embryos and the molecular signalling that speeds growth of replacement teeth when functional teeth are lost.
The study appears in Proceedings of the National Academy of Sciences.
Reference: Specialized stem cell niche enables repetitive renewal of alligator teeth
