Humans might be able to regrow their teeth like sharks

Film star Jaws the shark showed how to put the bite on just about anything thanks to a plentiful supply of replacement teeth. Now humans might also be able to grow all the replacement teeth they need thanks to research from the University of Sheffield.

Scientists there have tracked down the genes used by sharks to produce a continual supply of new teeth. Humans, it turns out, also have these genes but they are not active in humans other than when our baby teeth and then adult teeth grow in.

Researchers led by Dr Gareth Fraser from the university’s department of animal and plant sciences believe it may be possible to reactivate this set of genes so humans too can replace lost or damaged teeth.

Sharks are hugely successful predators because of their backward pointing razor sharp teeth, says Dr Fraser. Equally important is the continual process of replacement that keeps the shark’s bite its sharpest.

Yet we have the same set of “tooth genes” the researchers say and if these can be switched on then it may open the way to regrowth of new teeth in humans.

The scientists tracked down the key genes by studying catshark embryos. The genes trigger the growth of the first set of teeth but then just keep resetting themselves for round after round of replacement teeth delivered in a conveyer belt like system, the scientists say.

They also showed that these genes have been conserved through 450 million years of evolution, so clearly this was a trait that has served the shark well.

Other vertebrates also picked up this useful trait but only a few species for example rays, managed to keep the genes activated.

The question is whether a method can be found to switch these genes on in humans temporarily so that replacement teeth will appear after injury or decay.