RNA polymerase shown to read an eight-letter genetic alphabet accurately
Researchers at UC San Diego have used detailed imaging to show that a key cellular enzyme can faithfully transcribe synthetic DNA letters alongside natural ones, advancing work on expanded genetic systems.
All life on Earth encodes genetic information using four DNA letters — adenine, thymine, cytosine, and guanine. Researchers at the University of California San Diego have now demonstrated that RNA polymerase, the enzyme responsible for reading DNA and producing RNA, can accurately transcribe a synthetic eight-letter genetic alphabet that doubles this natural set.
Published findings described in ScienceDaily reporting draw on detailed structural imaging to show that the enzyme handles the four synthetic, unnatural base pairs in ways that are mechanistically similar to its handling of the four canonical letters. The work suggests that the machinery of gene expression does not fundamentally break down when confronted with expanded alphabets, a question that had remained open in the field of synthetic biology.
The research contributes to an effort, sometimes called hachimoji DNA (from the Japanese for 'eight letters'), to build genetic systems capable of storing more information per unit length or performing biological functions inaccessible to natural nucleic acids. Potential applications discussed in the synthetic-biology literature include novel data-storage materials and engineered organisms with expanded chemical repertoires, though these remain research-stage ambitions.
The finding is reported via ScienceDaily; the primary research source and journal have not been specified in available feed materials. Readers seeking the peer-reviewed article should search the UC San Diego research communications office for the corresponding publication.
Plain-language version
For patients, families, and general readers. Educational only — not medical advice.
DNA — the molecule that carries genetic instructions in every living cell — uses four chemical 'letters'. Researchers at the University of California San Diego have shown that a cell's machinery for reading DNA can also accurately read a made-up alphabet of eight letters, doubling the natural set. Scientists designed the extra four letters in the laboratory; they do not occur in nature.
This kind of research, sometimes called synthetic biology, explores whether it is possible to build genetic systems that go beyond what evolution has produced. Potential future uses that researchers discuss include new ways to store information or to engineer living cells with new abilities. These possibilities are at an early, exploratory stage and are not yet clinical applications.
This is an educational summary, not medical advice. If anything here raises questions for you, please speak with your GP or a clinical professional.
Sources
Read the original reporting — these are the public sources this summary draws from.
-
Primary source ScienceDaily · 2026-09-05Life uses 4 DNA letters. Scientists just made 8 work