Scientists Find & Replace DNA to Control What Cells Do
What if scientists could genetically alter cells to produce substances not found in nature?
No, this isn’t the plot of that sci-fi flick you watched last night; it’s a remarkable scientific achievement by a group of researchers from Harvard and MIT. The new technology allows scientists to engineer large-scale changes within the genetic code of a living cell by replacing specific DNA sequences.
"We're essentially programming the cell to do our bidding," said Harris Wang, one of the lead researchers on the project. "[This technology] enables us to manipulate the genome as if it’s a scaffold, and build upon it."
The process works by combining two technologies developed by the researchers: MAGE (Multiplex Automated Genome Engineering), which the scientists debuted in 2009, and a newer innovation called CAGE (Conjugative Assembly Genome Engineering). MAGE performs the actual "find-and-replace" function, by targeting certain DNA sequences within a cell and replacing them with a new sequence. Meanwhile, CAGE consolidates changes made to individual cells.
"Someone recently described [the technology] as being like the find-and-replace feature in a word processor, which is a good way to think about it," said Peter Carr, another one of the researchers on the project.
The researchers are currently testing the model on lab-strain E. coli cells. First, MAGE was used to make a total of 314 edits to the genomes of 32 strains of E. coli. CAGE was then implemented to boil down all 314 changes into a single strain. The process is nearly complete, and will hopefully result in what Wang describes as "a chimeric genome."
The innovation, Carr said, "opens up the opportunity to program new things into the genetic code," allowing scientists to create "new building blocks for the machines of life." One possible application would be to alter the genes of certain crops — such as potatoes, for instance — to make them invulnerable to viruses.
"When we first started out, it wasn’t certain that this project was even feasible, both biologically and technologically," said Farren Isaacs, another of the researchers. "So it's really gratifying to see that we’ve been able to do it."