UC San Diego Researchers Expand Genetic Alphabet to Eight Letters, Doubling Natural DNA

Scientists at UC San Diego have demonstrated that a key cellular enzyme can accurately read an eight-letter genetic alphabet, effectively doubling the four letters found in all known life on Earth. Detailed imaging revealed that RNA polymerase handles these synthetic DNA letters in ways surprisingly similar to natural ones. This finding, published in Nature Communications, brings researchers closer to building expanded genetic systems that could perform entirely new biological functions, with potential applications in diagnostics, therapeutics, and engineered biological systems.