What is genome editing?
Genome editing was first developed in the 1990s and has gained prominence in recent years, with wide-ranging applications in agriculture, medicine, and environmental remediation. It refers to a set of modern biotechnology tools used by scientists to make precise changes in an organism’s DNA, also known as the genome. This is akin to how you would edit a document on your computer by deleting, replacing, or adding a more suitable word.
Genome editing tools can be viewed as molecular scissors that cut DNA strands, causing the strands to break. The cells are able to repair the cuts and the repaired DNA is sometimes slightly different from the original sequence. While small breaks in DNA naturally happen in all organisms, genome editing tools allow scientists to direct where the cuts happen!
In the food and agriculture sector, genome editing allows crop developers to make precise changes in the existing DNA of a crop to impart useful properties. On the one hand, these changes can be small and do not introduce foreign DNA. The resulting genome edited crop is equivalent to crops found naturally or bred using conventional breeding techniques. On the other hand, genome editing can introduce foreign DNA into a crop – the resulting crop is equivalent to a genetically modified crop.
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What are the benefits of genome editing?
For thousands of years, farmers have selected crops with useful properties based on their naturally occurring DNA variations. However, this selection process is imprecise and takes decades of continual breeding.
Genome editing can expedite the breeding of desirable crops that would otherwise require more time using conventional methods, allowing such crops to be grown in approximately 1 – 5 years. Recent examples of new crop varieties bred using genome editing include soybeans that produce oil with increased monounsaturated fat content, rice that is resistant to disease, and tomatoes that are more suited for indoor farming.
The development of such food products provides consumers with more food choices. Farmers also benefit when their crops are more resistant to diseases and pests, thereby reducing the use of pesticides and increasing their crop yields.
How does SFA ensure the food safety of genome edited crops and food products in Singapore?
SFA’s priority is to ensure the safety of food consumed in Singapore. As genome editing becomes more prominent and prevalent, SFA has developed a science-based, risk-proportionate regulatory framework for genome edited crops used in food.
Under this framework, genome edited crops that are equivalent to conventionally bred crops are not required to undergo pre-market safety assessment and approval. These genome edited crops will be subject to the same food safety monitoring regime as conventionally bred or naturally occurring crops. Nonetheless, crop developers are encouraged to notify SFA prior to the sale of such crops here.
For genome edited crops that could not have been generated via conventional breeding (i.e. foreign DNA is introduced resulting in it being equivalent to a genetically modified crop), SFA will require crop developers to undergo SFA’s pre-market safety assessment and approval process before they can be used in food. These requirements are put in place to ensure that such genome edited crops are safe to consume as conventionally bred or naturally occurring crops. To protect consumers, SFA also has in place a testing regime to ensure that only approved genome edited crops with foreign DNA are available on the market.
As food safety is a joint responsibility, SFA will continue to work closely with the food industry and consumers to ensure the safe use of genome edited crops in food.
About the author
Dr Tan Yong Quan is a Scientist from the Risk Assessment and Communications Department of the National Centre for Food Science. He holds a PhD in Biochemistry from the National University of Singapore and is currently responsible for matters related to genetically engineered food as well as new food sources and production systems.