Scientists have produced a semi-synthetic version of a bacterium that has an extended genetic code. All Earth’s lifeforms use four chemical units, or bases, arranged in pairs within DNA, to drive their biology. The modified E. coli bug produced at The Scripps Research Institute in California incorporates two more bases that were wholly designed in the lab.
The team tells Nature magazine that its altered bacterium could be used to make a range of novel drugs and materials. Prof Floyd Romesberg and colleagues have been working towards this study result since the 1990s. They had previously shown how the new bases – known as d5SICS and dNaM, or X and Y for simplicity – could be stably incorporated as a pair into the DNA molecule in vitro, in the “test tube”.
The latest advance sees them introduce this supplemented DNA into a living organism. What is more, the modified E. coli bug is able to copy the extended DNA and pass it down the generations. Edited from Semi-synthetic bug extends ‘life’s alphabet’.