TOKYO (AP) – Scientists have discovered the ultimate case of regeneration: Some decapitated sea snails can regrow hearts and whole new bodies.
Reported in a biology journal Monday, this ‘natural wonder’ could ultimately help scientists better understand and address human tissue regeneration.
Biology researcher Sayaka Mitoh said she likes to study Japanese sea snails because they are small, cute and weird. They can even photosynthesize for a short time as a plant that gets food from the sun.
One day in the lab she saw something bizarre: a sea slug had decapitated itself and its head just kept moving and living. Then a few more did the same, according to a study in Current Biology.
So the doctoral student and Yoichi Yusa, a professor of aquatic ecology at Nara Women’s University, tried it for themselves and cut the heads of 16 sea snails. Six of the creatures began to regenerate, and three succeeded and survived. One of the three even lost twice and got his body back. Two different species of Japanese sea snails did this regeneration trick.
Other creatures can shed body parts when needed, such as when some lizards drop their tails to get away from a predator, in a biological phenomenon called autotomy.
“We think this is the most extreme case of autotomy,” said Yusa. “Some animals can autotomize their legs, appendages or tails, but no other animal sheds its entire body.”
Scientists thought that such a relatively large animal – one of the species of sea snails can grow to 6 inches in length – could not survive without a heart to pump blood and nutrients to the brain, said Canadian marine biologist Susan Anthony, who was not. part of the study.
But the same thing that makes this strain spectacular is probably what helps it do the trick, Anthony and Yusa said.
When these sea snails eat a certain type of algae, they can photosynthesize their food from sunlight and oxygen, just like a plant, for about 10 days, Yusa said. What likely happens after decapitation is the head behaves like a plant, he said. It turns green and gets its energy from oxygen and sunlight. The fact that it helps little, he said.
These strains likely evolved this feat as a way to control parasites, Mitoh and Yusa said.
Humans may be able to learn something useful from the sea creatures, several scientists said. What’s especially intriguing is that these sea snails are more complex than flatworms or other species known to regenerate, said Nicholas Curtis, a professor of biology at Ave Maria University who was not part of the study.
“It’s a miracle of nature, of course, but understanding the underlying molecular mechanisms will help us understand how our cells and tissues can be used to repair damage,” Curtis said in an email.
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