Human teeth could eventually be made to regrow just like those of sharks as we still possess the same genes that allow regrowth, scientists have found.
Sharks and other fish regrow their teeth repeatedly through their lives while humans have the capacity to regrow their teeth just once.
But now scientists at the University of Sheffield have discovered that the same network of genes that allow sharks to regrow teeth is present in humans.
The same genes have been retained over 450 million years of evolution – when humans and sharks had a common ancestor - and mean we have the capability to regrow our teeth if a way can be found to switch these genes on.
Dr Gareth Fraser and colleagues analysed the teeth of catshark embryos, and identified the genes involved during stages of early shark tooth formation.
These genes continue to be used to grow further teeth and are found in cells called the dental lamina, which are responsible for the lifelong continuation of tooth development and regeneration in sharks.
The same genes are still present in humans - deriving from the time when humans and sharks had a common ancestor.
Dr Fraser, whose research has been published in Developmental Biology, said: 'Sharks can regenerate their teeth throughout their lives.
'The good news for us as humans is the genes that make these teeth regrow are shared by all vertebrates [creatures with skeletons] including humans.
'What it means is because we have the same genes to make teeth, we also have a regenerative program.
'We make two sets of teeth, but humans need more teeth, whether through loss or damage, so our second set are really quite valuable.