The essential element for all life on earth is DNA. Different combinations of DNA’s nucleotide bases—adenine (A), cytosine (C), guanine (G), and thymine (T)—produce the range of genetic expressions of a living being. However, what if more letters could be added to the genetic alphabet?
In 2014, Floyd Romesberg—a chemical biologist a the Scripps Research Institute in La Jolla, California—did just that. He and his team added an X and a Y to the natural genetic alphabet to a strain of E.coli bacteria. They’ve now taken their work a step forward and have published a sturdy in the journal Nature.
In the study, Romesburg and his team demonstrated how this partially synthetic strain of E.coli processes instructions from the added X and Y nucleotide bases, expressing new proteins.
“This is the first time ever a cell has translated a protein using something other than G, C, A, or T,” Romesberg said to Reuters.
While the actual changes to the organism were small, the findings are significant. “It’s the first change to life ever made.”
But creating new forms of life isn’t the primary goal of Romesberg’s work expanding the genetic alphabet. Instead, he is interested in using it to create new types of proteins that can be used to treat disease.
Romesberg formed a company, Synthorx Inc, in 2014 to work on developing new protein-based treatments.
“A lot of proteins that you want to use as drugs get cleared in the kidney very quickly,” Romesberg said. But this new system would enable scientists to attach fat molecules to drugs to keep them in the body for longer.
But this development toward the creation of semi-synthetic organisms could raise concerns of hybrid life forms spreading beyond the lab, a concern Romesberg is aware of. The system his team uses, however, makes escape highly unlikely.
“They can’t escape,” Romesberg noted. “There’s no ‘Jurassic Park’ scenario.”