TOKYO (Reuters) – Japanese researchers have shown that a type of sea slug is capable of self-decapitating and regenerating their bodies, a finding that may have ramifications for regenerative medicine.
The mechanism is believed to be an extreme method for the body to get rid of parasites, researchers Sayaka Mitoh and Yoichi Yusa wrote in a study published in the journal Current Biology this week. Green slugs have algae cells on their skin, so they can feed on light like a plant until they develop a new body, which takes about 20 days.
Mitoh, a doctoral researcher at Nara Women’s University, once realized that a sea slug, known as sacoglossana, had spontaneously separated the head from the body.
“I was surprised and thought I was going to die, but continued to move and eat with a lot of energy,” said Mitoh. “I kept an eye on him for a while and he regenerated his heart and body.”
This led to a study showing that five of the 15 laboratory-created slugs and one wild slug separated their body from a specific spot on the neck during their lives. 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 a head again.
“One of the amazing things about stem cells is that they can be used to regenerate a heart and body from the tip of the animal’s head,” said Mitoh. “With more studies, we may be able to apply these findings to regenerative medicine, but it is still a distant hope at this stage.”
Other animals are known to intentionally separate and regenerate parts of the body, a mechanism known as an autotomy, but this extreme form was previously unknown, the researchers said.
They initially thought it could be a method to escape predators, but now they think it is designed to get rid of parasites that inhibit reproduction.
Reporting by Rikako Murayama and Rocky Swift in Tokyo; Edition of Karishma Singh