The genetic material of all creatures on earth is saved in the biomolecule Deoxyribonucleic Acid, the DNA. It consists of four components: the bases Adenin (A), Thymin (T), Guanin (G) and Cytosin (C). These appears as pairs in the combinations of AT and GC. Now, a team of scientists at the Scripps Research Institute in California, led by chemical biologist Floyd Romesberg, extend the alphabet with two new created 'foreign' building-blocks, called X and Y.
Researchers inserted an X-Y pair into the bacterium E.Coli and it was able to reproduce normally, though a bit more slowly than usual, replicating the X and Y along with the natural DNA.
“For the past 14 years, we have been creating and optimizing synthetic DNA bases in my lab. Today we have shown the first example of a synthetic base pair undergoing DNA replication in a single-cell organism.
The ability to incorporate and replicate a synthetic DNA base pair in vivo means that we have, for the first time, expanded the genetic alphabet to increase the amount of information that can be stored in DNA.” explains Romesberg.
The bioengineered E.Coli bacteria has the potential, for instance, to produce medications or help scientists to track biological reactions under the microscope. Therefore Romesberg already founded the biotech company Synthorx.
The new DNA contains just a single pair of the 'alien' X-Y blocks. The creation of a whole organism is a big challenge. “A lot of times people will say you’ll make an organism completely out of your unnatural DNA,” says Romesberg. “That’s just not going to happen, because there are too many things that recognize DNA. It’s too integrated into every facet of a cell’s life.”