The discovery of a class of “effector” proteins, called transcription activator-like (TAL) effectors has been used to alter genes in crops. It has applications for mammals, flies and worms as well. Plant geneticists can now use TAL-nucleases to introduce precise, favorable modifications in any region of the genome.
In one example, researchers removed a small stretch of DNA from the rice genome, which rendered it susceptible to bacterial blight, but it also no longer contained extraneous DNA. Since researchers can use this technique much more efficiently than conventional breeding processes, it is time saving and more efficient. This technique can replace the use of chemical mutagens or radioactive treatments to achieve the same results.
Since the DNA was removed from the sample rice plants, technically, scientists would consider it the opposite of transgenic plants.
GM opponents often argue that insertion of extraneous DNA can cause new, unknown allergenicity and foreign DNA raises the specter of contamination of other plants and the environment.
Using the TAL effectors to remove DNA will likely challenge anti-GMO opponents. However, since many are also anti-technology, it’s unlikely they will embrace this methodology either.
To view the history of the technology, click here.