In a new study in Nature Biotechnology, Harvard University researchers describe how they've bioengineered an artificial jellyfish using heart cells from a rat, reports Ed Yong at Nature News. The result — a synthetic creature called a medusoid — is morphologically a jellyfish and genetically a rat. It swims and pulses like a jellyfish when placed in an electric field, Yong says. The researchers, led by Harvard's Kit Parker, built the medusoid as a way of understanding how muscular pumps work, with the hope of using that knowledge to create more accurate models of the human heart. "It is an engineer's approach to basic science: prove that you have identified the right principles by building something with them," Yong adds.
The team began by mapping the cellular structure of juvenile moon jellies, and then created a structure with the same physical properties using a single layer of rat heart muscle on a sheet of polydimethylsiloxane. "Usually when we talk about synthetic life forms, somebody will take a living cell and put new genes in," Parker says of the project. "We built an animal. It's not just about genes, but about morphology and function." They now plan to build a medusoid from human heart cells, Yong says, and hope to use that to test new drugs. "You've got a heart drug? You let me put it on my jellyfish, and I'll tell you if it can improve the pumping," Parker adds.