I went to the CRISPRcon 2019 at the University of Wageningen. A conference about improving crops with CRISPR-Cas. Here is a summary of what I learned.

CRISPR-Cas is a revolutionary technology to change the DNA of plants, microbes, animals and humans. It transformed genome editing and was the scientific breakthrough of the year in 2015 according to the journal Science. There are two components to CRISPS-Cas a ‘guide’ and a ‘scissor’. Cas is the scissor which is guided to a specific genome by a CRISPR RNA. Once at its target, Cas cuts the DNA.

The mechanism has been used by bacteria for millions of years to protect themselves against viruses. Homo sapiens turned it into a tool that makes genome editing cheaper, faster, more efficient and more versatile than ever before.

The genome is a sequence of DNA building blocks or DNA ‘letters’. For example, the genome of the intestinal bacterium E. coli consists of a sequence of about 3 million DNA letters. The human genome has 3.2 billion DNA letters

Since we invented agriculture 10,000 years ago we have been modifying plants. We selected the best performing plants and kept their seeds for sowing. This often went against natural selection, because traits were chosen that were convenient for humans, such as a higher yield or larger fruits. Almost all of our crops today are the result of human selection and intervention. The great diversity of cabbages is a good example; cauliflower, brussel sprouts, kale, broccoli, etc. are created by natural spontaneous mutations from the same ancestor.

In the 1930s breeders started to use mutation breeding. A breeding type that uses radiation or chemicals to make changes to DNA at a high rate. The result is a large collection of seeds with random DNA mutations which are then used to identify plants with desirable, improved characteristics. Traditional mutation breeding has resulted in 3,200 improved crop varieties in more than 175 plant species, including rice, maize, wheat, banana, tomato, pumpkin and soya. The striking color of the flesh and the sweet taste of the pink grapefruit is a good example of a new crop characteristic created by this form of breeding. Thanks to its long history and its role in creating improved crop varieties, products developed through mutation breeding are exempted from GMO regulations in Europe.

CRISPR-Cas induces highly controlled, precise DNA mutations. This allows breeders to dampen unwanted characteristics or strengthen desirable ones. The advantage of genome editing over traditional mutation breeding is that only desired mutations are created without undesirable random mutations. It is therefore considered an advanced over mutation breeding. The result is the same, we only get there faster and more efficiently. An additional advantage is that it can change different characteristics simultaneously and can be used to incorporate DNA fragments from different species with high precision. It allows scientist to switch off genes to see what they do. Knowledge that can be used to edit crops to protect them against drought, diseases and to raise yields. The most promising innovations that CRISPR-Cas assist in is lowering the use of pesticides by making crops that are resistant to fungi, bacteria and insects and use water and fertilizer more efficiently.

In July 2018, the European Court of Justice ruled that agricultural crops in which mutations have been made with CRISPR-Cas must be regarded as GMO crops and thereby impose strict regulations. There is a large backlash amongst scientists and researchers at CRISPRCon 2019 as they do not understand why radiation-derived mutants do not fall under these rules, but the CRISPR-Cas mutants do. They consider CRISPR-Cas mutations to be safer and much more cost-effective.

Are you pro GMO? Should CRISPR-Cas be allowed in the EU like the US?