Should We Rewrite the Human Genome?

Scientists are engineering a new living thing: a radically modified version of the lowly bacterium E. coli. In an article in Science from August, researchers at Harvard University described an ongoing project to build the genetic code of E. coli from scratch, but with major revisions to create a new strain unlike any in existence.

The modified E. coli is meant to be so foreign to viruses that they will not be able to infect it. George Church, the principal investigator on the study, told me the finished product “will be completely, unassailably resistant to all viruses, even viruses never seen before.” This offers important advantages in industrial processes such as pharmaceutical and biofuel manufacturing, said Matthieu Landon, one of the lead authors on the paper. (Genzyme, a biotechnology company, suffered a crippling viral contamination in 2009 at its Allston, MA, plant that made two essential drugs unavailable for the patients who depended upon them. A virus-resistant cell would not be vulnerable to such contamination.)

The E. coli project is a step toward the synthesis of a human genome...