Sheffield academic shows how the fearsome shark could help prevent human tooth loss

But now a team of researchers at a Yorkshire university are hoping to use them to help make improvements in human dentistry.

Scientists have known for some time that some fish, such as sharks, develop rows of highly specialised teeth which are capable of regenerating throughout their lives.

However academics have not properly understood how this happens until now.

A study by Sheffield University has identified a network of genes which allow sharks to develop and regenerate their teeth again and again.

The genes also allow sharks to replace rows of their teeth using a conveyer belt-like system, making them deadly hunters.

Now scientists hope this new insight into the workings of shark’s teeth could be used to pave the way for the development of therapies to help humans with tooth loss.

Sheffield University’s research team, led by Dr Gareth Fraser from the Department of Animal and Plant Sciences, has identified a special set of epithelial cells form, called the dental lamina, which are responsible for the lifelong continuation of tooth development and regeneration in sharks.

Humans also possess this set of cells, which facilitate the production of replacement teeth.

However in humans these cells are only used to produce two sets of new teeth – baby and adult teeth.

Once this happens this set of specialised cells is lost.

The Sheffield-led team have shown that these tooth-making genes found in sharks are conserved through 450 million years of evolution, and probably made the first vertebrate teeth.

These ‘tooth’ genes, are thought to have made all vertebrate teeth from sharks to mammals, however in mammals like humans, the tooth regeneration ability, that utilises these genes, has been highly reduced over time.

Sheffield University’s Dr Gareth Fraser said: “We know that sharks are fearsome predators and one of the main reasons they are so successful at hunting prey is because of their rows of backward pointing, razor-sharp teeth that regenerate rapidly throughout their lifetime, and so are replaced before decay.

“The Jaws films taught us that it’s not always safe to go into the water, but this study shows that perhaps we need to in order to develop therapies that might help humans with tooth loss.”

Through analysing the teeth of catshark embryos, the Sheffield University researchers “characterised the expression of genes during stages of early shark tooth formation.”

Their research found that these genes participate in the initial emergence of shark’s teeth and are then re-deployed for further tooth regeneration throughout the creature’s life.

The study suggests that at the beginning of the sharks’ evolutionary history, their teeth were most likely to be continuously regenerating.

Scientists say that sharks used a core set of genes which were instrumental in the species evolving to maintain the ability to re-deploy the genes to replace teeth when needed.

This research carried out by Sheffield University was supported by the Natural Environment Research Council, and the Leverhulme Trust.

The Natural History Museum also provided shark specimens, which were scanned in the museum’s Imaging and Analysis Centre.

Findings from the research are published today in the journal Developmental Biology.