By Pete Shanks
George Church and 15 co-authors last week published a paper in Science that represents a potentially important step in the direction of massively altering genomes. To use a word-processing metaphor, they did a search-and-replace in an E. Coli genome to change all 314 occurrences of TAG to TAA; since the two are essentially synonyms (they are both stop codons), swapping them does not by itself change the meaning. But it’s very significant, as noted in their abstract:
Our methods treat the chromosome as both an editable and an evolvable template, permitting the exploration of vast genetic landscapes.
Having deleted TAG, as Frederick Blattner (who was not part of the team) told New Scientist, they might then be able to reprogram the cell’s machinery to assign the empty space to produce whatever they wanted, perhaps an entirely new amino acid and thus entirely novel proteins:
“That’s the vision, completely refactoring the genome to where it is quite substantially different from any other life forms. … We can manipulate the fundamental aspects of life.”