Species of animal is able to regenerate organs fully following dissection

The tubular ascidians, commonly found in the coral reefs of Eilat, are considered to be the invertebrates "closest to humans from an evolutionary point of view."

The Polycarpa mytiligera species of ascidian themselves are commonly found in the coral reefs of Eilat. (photo credit: TAL GORDON/TEL AVIV UNIVERSITY)
The Polycarpa mytiligera species of ascidian themselves are commonly found in the coral reefs of Eilat.
(photo credit: TAL GORDON/TEL AVIV UNIVERSITY)
An animal in the Red Sea has been discovered to be able to regenerate all of its organs even after being dissected into three parts, Tel Aviv University (TAU) announced in a statement.
“Since the dawn of humanity, humans have been fascinated by the ability to regenerate damaged or missing organs," said Prof. Noa Shenkar, one of the lead researchers. "Regeneration is a wonderful ability that we have, to a very limited extent, and we would like to understand how it works in order to try and apply it within our own bodies. Anyone snorkeling in the Red Sea can find this intriguing ascidian, who may be able to help us comprehend processes of tissue renewal that can help the human race.”
Researchers found an ascidian – stationary, tubular, invertebrate filter feeders – from the species Polycarpa mytiligera, a marine animal commonly seen in the Gulf of Eilat, that possesses the capability to regain function of "its missing body systems within a short period of time."
“It is an astounding discovery, as this is an animal that belongs to the Phylum Chordata - animals with a dorsal cord - which also includes us humans,” said Shenkar. “The ability to regenerate organs is common in the animal kingdom, and even among chordates you can find animals that regenerate organs, like the gecko who is able to grow a new tail.
"But not entire body systems," Shenkar added. "Here we found a chordate that can regenerate all of its organs even if it is separated into three pieces – with each piece knowing exactly how to regain functioning of all its missing body systems within a short period of time.”
Ascidians, of which more than 2,000 species exist, are found in oceans and seas worldwide. The species is often known to camouflage itself as lumps on rocks, and is therefore hard to spot and discern from the inanimate objects they latch onto.
The Polycarpa mytiligera species of ascidian are commonly found in the coral reefs of Eilat.
“By all accounts, the ascidian is a simple organism, with two openings in its body: an entry and an exit,” said Tal Gordon, one of the study leaders whose doctoral dissertation included this new research. “Inside the body there is a central organ that resembles a pasta strainer.
"The ascidian sucks in water through the body’s entry point, the strainer filters the food particles that remain in the body, and the clean water exits through the exit point. Among invertebrates, they are considered to be the closest to humans from an evolutionary point of view.”
Ascidians are generally known for their regenerative ability, but it is typically associated with asexual reproduction capabilities. There has never been such a high regenerative capacity found in a chordate animal that reproduces only by sexual reproduction – until now.
“There are species of ascidians that perform simple regeneration in order to reproduce," Gordon said. “These are species with a colonial lifestyle, with many identical individuals connected to one another. They replicate themselves in order to grow.
"In contrast, the ascidian from Eilat, Polycarpa mytiligera, is an organism with a solitary lifestyle, without the capacity for asexual reproduction, similar to humans. In previous studies, we showed that this species is able to regenerate its digestive system and its points of entrance and exit within a few days," Gordon said.
"But then we wanted to see if it is capable of renewing all of its body systems. We took a few individual ascidians from Eilat and dissected them into two parts, which were able to replenish the removed sections without any problem," Gordon continued. "In a subsequent experiment, we dissected several dozen ascidians into three fragments, leaving a part of the body without a nerve center, heart, and part of the digestive system.
"And contrary to our expectations, not only did each part survive the dissection on its own, all the organs were regenerated in each of the three sections," he concluded." Instead of one ascidian, there were now three. This is very astonishing. Never before has such regenerative capacity been discovered among a solitary species that reproduces sexually, anywhere in the world.”
Their findings were published in the scientific journal Frontiers in Cell and Developmental Biology.
Zachary Keyser contributed to this report.