Scientists Say They’ve Made Cells That Feed, Grow and Reproduce, Bringing Them One Step Closer to Building Life From Scratch
The human-made cells show many hallmarks of life, but they can’t make all their necessary internal structures or divide for that many generations
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Knights of science have long chased a biologic holy grail: transforming a soup of raw chemicals into self-sustaining life. Now, a team led by synthetic biologist Kate Adamala, of the University of Minnesota, claim to have made a huge leap toward that lofty goal.
They’ve developed simple artificial cells that can feed, grow, multiply and even compete for food, according to a study posted to the preprint server bioRxiv on July 2. The work has not been peer-reviewed. While the human-made cells aren’t quite alive—they can’t make all their necessary machinery or divide for that many generations—they show many signs of life.
“It is not as robust, as fast or as good at most of its functions as a natural cell, but it is proof of principle that molecules can reconstitute behaviors that, up until now, we only associated with natural living cells,” Adamala tells Guardian’s Ian Sample.
“We’re going to remember this moment,” Roseanna Zia, a computational biologist at the University of Missouri who was not involved in the research, tells the New York Times’ Carl Zimmer and Marco Hernandez.
Scientists have been attempting to create cells in the lab for decades. The feat could help researchers better understand life’s foundations and pump out certain chemicals that humans need. For instance, people with diabetes rely on synthetic insulin that’s made by bacteria and yeast.
Adamala and her colleagues started down this path by trying to recreate natural cell division, a part of reproduction, by making a stripped-down version. But then they flipped their approach and worked from the bottom up, which would allow them to fully understand each component. The team created synthetic cell membranes that gathered proteins from the environment, and when they collected enough, the membrane’s surface warped inward until it split into two.
After that, the researchers decided to attempt to build a whole cell from scratch. They started with water-filled spheres enclosed by oily membranes, called liposomes. Then, they inserted DNA encoding only 36 genes for essential functions, borrowed from a virus and the common bacterium Escherichia coli. (For context, the latter microbe has about 4,400 genes.)
The resulting creation was dubbed SpudCell because of its potato-like appearance, as an homage to Sputnik and the dawn of the space age, and because of Adamala’s heritage. “I’m Polish,” she tells the Guardian. “I’m mostly made of potatoes.”
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Once they were floating in laboratory flasks—filled with a soup that contained crucial chemicals—the SpudCells began to behave like living organisms. They gobbled up provided molecules, like ATP, the primary “energy currency” for all known life. They also fused with “feeder” liposomes, which contained larger necessities, such as enzymes.
As the SpudCells ate, they expanded. Within hours, they were ready to replicate. The team used the same cell division technique that kick-started the project, adding special proteins to get the membranes to split—which successfully created new cells that grew.
The synthetic cells even demonstrated a rudimentary capacity to evolve. When the researchers pitted original SpudCells against a mutant strain designed to bind more tightly to the feeder bubbles, the mutants successfully outcompeted the originals over five generations.
“It is dazzling that [Adamala] has put these things all together,” John Glass, a synthetic biologist at the J. Craig Venter Institute in La Jolla, California who was not involved in the study, tells the Times.
Despite these extraordinary features, SpudCells are far from perfect replicas of natural life. Even though they have the necessary genes, the cells currently lack the ability to make their own ribosomes—the cellular factories that build proteins. The scientists manually supply them with E. coli ribosomes via the feeder liposomes, but even then, the protein-making machinery stops working after five to ten generations.
Not everyone is upbeat about the development. “It’s a very cool paper,” Seraphine Wegner, a biochemist at the University of Münster in Germany who was not involved in the work, tells Science’s Kai Kupferschmidt. “But I don’t think it means we’re close to creating a fully synthetic cell.”
John Dupré, a philosopher of biology at the University of Exeter in England, questions whether these engineered structures will ever outshine modified bacteria when it comes to manufacturing drugs, food, fuel or other materials. He tells the Guardian that they might not even reveal much about the foundations of life.
“It will, perhaps, provide a compelling argument against those who think there is some immaterial substance in addition to the chemicals that breathes life into material stuff,” Dupré says. “But almost no scientist now believes this.”
Still, Adamala thinks that SpudCells could eventually create substances that natural cells can’t, like a new medicine. She has joined forces with Drew Endy, a synthetic biologist at Stanford University who was not involved in the study, to found a nonprofit research organization called Biotic that aims to build a community that works together on scientific advances, including the artificial cells
Endy likens SpudCells to the Wright brothers’ first controlled flight in 1903. “The Wright flyer flying for 12 seconds doesn’t get you a 737,” he tells the Times. “This is just the beginning.”