TOKYO (Reuters) – Japanese researchers have shown that a type of sea snail is able to decapitate itself and regress its body, a discovery that could have ramifications for regenerative medicine.
The mechanism is believed to be an extreme way for the body to get rid of parasites, researchers Sayaka Mitoh and Yoichi Yusa wrote in a study published in Current Biology this week. Green slugs have algae cells in their skin, so they can feed on light like a plant until they develop a new body, which lasts about 20 days.
Mitoh, a doctoral researcher at the Women’s University of Nara, noticed one day that a sea slug, known as sacoglossan, spontaneously detached its head from its body.
“I was surprised and thought he was going to die, but he kept moving and eating quite vigorously,” Mitoh said. “I kept an eye on him for a while and he regenerated my heart and body.”
This led to a study that showed that five out of 15 snails raised in the laboratory and one in the wild separated their bodies from a certain point on their necks during their lifetime. One did it twice. Each time, the animal’s heart was left behind in the body, which continued to live for some time, but did not grow again.
“One of the amazing things about stem cells is that they can be used to regenerate a heart and a body at the edge of the animal’s head,” Mitoh said. “With further studies, we will be able to apply these findings to regenerative medicine, but this is still a distant hope at this stage.”
Other animals are known to intentionally detach and regress parts of the body, a mechanism known as autotomy, but this extreme form was not previously known, the researchers said.
They initially thought it might be a way to get rid of predators, but now I think it was done to get rid of parasites that inhibit reproduction.
Reporting by Rikako Murayama and Rocky Swift in Tokyo; Montage by Karishma Singh