In brief: After a scientist added X and Y nucleotide bases to E. coli bacteria’s natural genetic alphabet, the DNA generated new proteins. This is the first time an organism has made proteins using anything other than the natural G, C, A, and T bases.
New, Semi-Synthetic Life
At the core of all life on Earth is the molecule deoxyribonucleic acid (DNA). From the different combinations of DNA’s nucleotide bases — adenine (A), cytosine (C), guanine (G), and thymine (T) — come the various genetic expressions of a living being. But what if you could add more letters to this genetic alphabet?
Back in 2014, chemical biologist Floyd Romesberg did just that. He and his team at the Scripps Research Institute in La Jolla, California, expanded the natural genetic alphabet to include an X and a Y in a strain of E.coli bacteria. Now, they’ve taken that work one step further through a study recently published in the journal Nature.
In this new study, Romesberg and his colleagues demonstrate how their partially synthetic strain of E.coli can process instructions from its additional X and Y nucleotide bases to express new proteins.
Creating “Artificial Life?”
Thankfully, Romesberg and his team have no intention of using their research to provoke some kind of explosion of new, hybrid life forms. As Romesberg told Reuters, his X and Y nucleotide bases can’t bond with DNA’s natural bases, nor can these semi-synthetic organisms (SSOs) survive outside a laboratory setting. “They can’t escape,” Romesberg said. “There’s no Jurassic Park scenario.”
Still, as University of Waterloo associate professor Brian Ingalls told Futurism, we must be cautious when dealing with the manipulation of life.
“Based on our knowledge of how life works (at the molecular level and above), it’s not worthwhile to attempt a distinction between ‘natural’ and ‘artificial’,” he said. “We can, however, distinguish ‘new’ from ‘old,’ and there we should be concerned about the potential for new organisms to disrupt existing ecosystems.”
As Ingalls noted, Romesberg’s study is designed in such a way as to prevent such disruption. “New organisms whose molecular mechanisms are sufficiently different from (known) biochemistry are far less likely to interact in unpredictable ways with…