The genome engineering methods currently used, particularly in mammalian cells, are difficult and inefficient. This has led scientists to search for programmable gene editing technologies, the most promising of which is the CRISPR-Cas9 system.
To date, there’s no medical therapy on the market developed using gene editing. Likewise, there’s no crop on the market that has been engineered using CRISPR-Cas9. However, studies have demonstrated that crops can be modified using the system (Miao et al provides an example of successful gene editing using CRISPR-Cas9 in rice). Consequently, many wonder whether crops generated through gene editing would be considered GMOs.
What are currently known as a GMOs or genetically modified organisms are transgenic crops, meaning that a gene from a different species has been added to their genome. But in the case of crops modified using CRISPR-Cas9, what’s edited was there to begin with. Technically, nothing has been added from a different species. So how will regulatory agencies categorize these crops?
The recent paper Regulatory uncertainty over genome editing provides a great summary of the regulatory issues. Huw Jones describes how the USDA has concluded that if you cannot distinguish an edit from a naturally occurring mutation, then it’s not a GMO.
Jones states that the European Union has yet to determine how these crops will be classified, because they consider something to be genetically modified if “it is altered in a way that does not occur naturally by mating and/or natural recombination”.
Read full, original blog: Gene Editing and GMOs
(The author also provides a very high level overview of the method summarizing a 2014 review entitled “Development and Applications of CRISPR-Cas9 for Genome Engineering” from the journal Cell, which is behind a paywall).