Scientists from Harvard and Caltech announce the creation of a bioengineered, swimming jellyfish made from rat cells.
You begin with an eight-armed silicon membrane. You harvest rat heart-muscle cells and organize them in a disctinct jellyfish-like pattern on your membrane. Lastly, you set your creature free in a vat of fluid, and schock it with electricity. You watch as your "jellyfish" swims away.
Scientists from Harvard and Caltech did just that, and they are calling their rat-celled, bioengineered jellyfish a "medusoid." They hope that by studying its pumping motions, they will be able to extrapolate a better understanding of another pump -- the human heart. Their paper appeared in an advance online version today in Nature Biotechnology.
"Morphologically, we've built a jellyfish. Functionally, we've built a jellyfish. Genetically, this thing is a rat," says Kit Parker, a biophysicist at Harvard University in Cambridge, Massachusetts, who led the work.
In 2007, Parker was searching for new ways of studying muscular pumps when he visited the New England Aquarium in Boston, Massachusetts. "I saw the jellyfish display and it hit me like a thunderbolt," he says. "I thought: I know I can build that." To do so, he recruited John Dabiri, a bioengineer who studies biological propulsion at the California Institute of Technology (Caltech) in Pasadena. "I grabbed him and said, 'John, I think I can build a jellyfish.' He didn't know who I was, but I was pretty excited and waving my arms, and I think he was afraid to say no."
Janna Nawroth, a graduate student at Caltech who performed most of the experiments, began by mapping every cell in the bodies of juvenile moon jellies (Aurelia aurita) to understand how they swim. A moon jelly's bell consists of a single layer of muscle, with fibres that are tightly aligned around a central ring and along eight spokes.
To make the bell beat downwards, electrical signals spread through the muscle in a smooth wave, "like when you drop a pebble in water", says Parker. "It's exactly like what you see in the heart. My bet is that to get a muscular pump, the electrical activity has got to spread as a wavefront."
Down the road, the team plans to build a medusoid that uses human heart cells, Yong reports. "You've got a heart drug?" Parker told Yong. "You let me put it on my jellyfish, and I'll tell you if it can improve the pumping."