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A team of researchers led by James Attwater at University College London has developed an artificial RNA system capable of copying itself, marking a significant advance in efforts to recreate the earliest steps of life in the laboratory. This achievement brings scientists closer to understanding how life might have originated on Earth billions of years ago.
The study centers on an engineered ribozyme—an RNA molecule with catalytic properties—that can assemble new RNA strands by joining together three-letter RNA building blocks, known as trinucleotide triphosphates. The system operates under cycles of hot, cold, acidic, and alkaline conditions, mimicking the fluctuating environments of primordial Earth. These conditions allow the artificial ribozyme to overcome a major challenge in RNA replication: the tendency of newly formed RNA strands to stick tightly to their templates, preventing further copying.
By using short RNA triplets, the researchers found a “sweet spot”—the triplets are long enough to bind effectively and prevent the strands from re-zipping, yet short enough to minimize errors. Under repeated cycles of heating and freezing, the ribozyme was able to weave these triplets into new complementary RNA strands. Although the current system can copy only about 30 of its 180 nucleotides before stalling, the team is optimistic about improving its efficiency.
Notably, the system not only replicated existing RNA templates but also generated new RNA sequences from random starting material, amplifying those fragments through multiple cycles. Some of the most robust amplification occurred with strands resembling parts of the ribozyme itself, hinting at early self-copying behaviors that could mirror the emergence of functional sequences in the origins of life.
This work supports the “RNA world” hypothesis, which proposes that early life forms relied on RNA molecules to both store genetic information and catalyze chemical reactions—functions now divided between DNA and proteins in modern cells.
If the ribozyme can be further refined to fully replicate itself and sustain this process indefinitely, researchers could directly observe mutation and natural selection in a test tube, offering unprecedented insight into the mechanisms that may have driven the origin of life.
The study is published in the journal Nature Chemistry.
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This article summarizes recent scientific research into artificial self-replicating RNA systems. While the findings represent a significant step forward, the system described does not constitute life itself, nor does it fully replicate the complexity of living organisms. The research provides a model for understanding possible pathways for the origin of life, but further advancements are necessary before laboratory systems can fully emulate natural biological processes.
