Rewriting the Code of Life

Donna Haraway is right. “The boundary between science fiction and social reality is an optical illusion.” Consider how scientists have recently reprogrammed bacteria to use a new amino acid. That is to say, they have not only introduced a 21st amino acid into the bacterium’s environment–in addition to the naturally existing twenty–but also reprogrammed the bacteria’s DNA to code for this new amino acid, so that the organism has genetic instructions for adding the acid to its proteins….

The full report on this research is here. The most amazing part of all this, to me, is that DNA itself has been recoded: “This method takes advantage of the fact that the genetic code contains three stop codons. Because only one stop codon is needed for translational termination, the other two can in principle be used to encode nonproteinogenic amino acids.” That is to say, the DNA code is redundant: several code sequences “mean” the same thing. This allowed the researchers to hijack certain code sequences, and give them a new significance.