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Artificial cell manages a few rounds of cell division
arstechnica.
Understanding the origin of life demands that scientists resolve a complex web of overlapping biological and chemical questions. Researchers have achieved significant progress in explaining how simple chemicals, abundant on early Earth, combined to form the complex molecules that sustain modern life. They have also traced the pathways through which these chemicals constructed the first genetic and catalytic molecules essential for biological function. However, despite these advances, scientists remain far from resolving a key conundrum: How did protective membranes eventually surround the first cells, creating distinct boundaries between life and the environment?
It is relatively straightforward to induce membranes to form spontaneously in water. These lipid bilayers naturally enclose anything dissolved within the water, including nucleic acids and other vital molecules. Once formed, however, these membranes effectively isolate their interior from the external solution. Any interesting chemical reactions occurring inside would rapidly consume available raw materials and grind to a halt. Without a mechanism to replenish these resources, the internal system would cease to function and die. This situation creates a fundamental paradox for origin-of-life theories: Cells must remain enclosed to maintain a stable internal environment, yet they must simultaneously remain open to exchange materials with the outside world.
Recently, a laboratory at the University of Minnesota announced the development of a simplified biological system in which a membrane encloses genetic material but can continually import new materials supplied to its environment. This system also undergoes spontaneous division, producing a few generations of "offspring" before the process eventually fails. Although the system remains heavily dependent upon human intervention for its survival and replication, it provides a new avenue for exploring questions about the origin of life and what a truly minimalistic form of life might look like. This experimental model, dubbed "SpudCells," represents a significant step toward creating a functional, albeit artificial, cellular system.
The work was conducted by a team led by Kate Adamala. At the time of the study, the research had not yet undergone peer review, although a draft manuscript had been posted online for public access. The project primarily involved assembling pieces of biological systems described or developed by other researchers and wrapping them in a protective membrane. Many of these biological components originated in viruses, which are notable for possessing stripped-down versions of systems that are far more elaborate in typical cells. By utilizing viral components, the researchers bypassed the arduous need to synthesize complex biological machinery from scratch.
For instance, the system used to copy the DNA of what Adamala termed a "SpudCell" is derived from a virus that infects bacteria, known as Phi29. A different research group had previously demonstrated that DNA encoding the proteins this virus uses to copy its genetic material could be placed inside a membrane. Inside that membrane, the DNA would replicate its own genetic code. The Minnesota researchers adapted this approach for their own system, which distributes roughly 90,000 bases of DNA across seven separate circular DNA molecules. This modular genetic architecture was specifically chosen to mimic the distributed nature of early genetic systems, which likely lacked the centralized organization of modern chromosomes.