It may not be what the Spice Girls imagined when they sang “2 become 1,” but scientists have discovered that kushi jelly actually fuses when it gets hurt.
Researchers studying the gelatinous marine invertebrate known as the sea walnut said they made the discovery after spotting an unusually shaped specimen in a laboratory aquarium.
“We were very excited,” said study co-author Dr. Oscar Arenas of the University of California, Berkeley.
Currently writing for the magazine “Current Biology”the researchers report that, among other features, the creature appeared to have two “ventral ends,” or back sides.
Arenas also said the animal had two mouths, something the team had never seen before.
“This led us to believe that it was the result of two separate animals merging,” he says. “That same night, we began an attempt to reproduce this observation.”
The research team paired sea walnuts collected from different locations at different times and removed part of each side of their bodies. Each pair was then fixed overnight with the wounds touching.
The results revealed that patients had fusion in 9 out of 10 cases.
“Once we realized that we could consistently reproduce the fusion, we shortened the time and ultimately found that fusion occurred within a few hours in a Petri dish,” Arenas said.
The researchers say this is not the first time that comb jelly (or ctenophores) transplantation has been reported, but that their experiment expands on such observations.
Among other findings, the researchers found that if you poked one side of the fused creature, both specimens would twitch or contract, a result that suggests the pair's nervous systems may have fused. This suggests that, the research team says.
Arenas said the discovery was interesting because little is known about the nervous systems of ctenophores.
“Furthermore, given that ctenophores are now thought to be descended from the ancestors of all other animals, studying how their nervous systems function is an important step in understanding the fundamentals of neural function. “It's very important to understand the principles,” he said.
“Furthermore, our observations suggest that ctenophores may serve as an excellent model for investigating the evolutionary process of self-recognition systems and advancing our understanding of tissue transplantation and regeneration in many tissues, including the nervous system. It suggests that there is.
The idea that the nervous system was integrated was supported by the finding that muscle contractions began to synchronize one hour after pairing the comb jellies. Experiments involving six fusion pairs suggested that after 2 h, 95% of the contractions within each pair were perfectly synchronized.
The researchers discovered that when one side of the comb jelly was fed food with a fluorescent label, the particles entered the digestive system of the other side. However, digested waste products were excreted asynchronously through both anuses.
Arenas said the study suggests that comb jellies have few mechanisms to distinguish their tissues from those of others of the same species.
“We believe this study provides insight into the molecular mechanisms of how single cells recognize themselves when they coalesce into multicellular animals.”
