AMES, Iowa - Research led by scientists at Iowa State University's Plant Sciences Institute has resulted in a process that will make genetic changes in plant genes much more efficient, practical and safe.
The breakthrough was developed by David Wright, an associate scientist, and Jeffery Townsend, an assistant scientist, and allows targeted genetic manipulations in plant DNA, which could have a huge impact on plant genetic work in the future.
Until now, when scientists introduced DNA into plants, they would randomly inject that DNA into the plant cell. There was no way of knowing if it was in the right place or if it would work until many resulting plants were tested.
The new technique harnesses a natural process called homologous recombination to precisely introduce DNA at a predetermined location in the plant genome through targeted DNA breaks generated by zinc finger nucleases. This occurs about 1 in 50 attempts and is very efficient compared to unassisted methods that allow the same changes at a rate as low as 1 in 10 million.
"I've been working in this field for 29 years, just when we started learning how to modify genes," said Townsend. "From that day, this was the goal -- to actually get the research to the point where you can have homologous recombination. Now, we've done it."
Using this process, a specific gene is located in a living cell, then a break is made in the DNA of that gene. When the cell begins to heal itself, existing DNA can be deleted or modified, or new DNA can be added near the break site. Afterward, the cell carries the genetic change and passes the change on to its offspring.
"It's like surgery, only on the molecular level," said Wright.
"It's been known for a long time that you if you make a break in a cell, you can get some DNA into that spot," said Wright. "It's just that you have three meters of DNA in a cell if you unwound it. Putting the break where you want it has always b
|Contact: Jeffery Townsend|
Iowa State University