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Hopes grow for gene editing

This safe new technology promises to take us far beyond GMOs. But will consumers let us use it?

DNA strand

A new technology called gene editing promises to pick up where GMOs have fallen short. In other words, with gene editing, farmers and consumers may benefit as much as chemical and seed companies. But for that to happen, farmers must become familiar with this new technology, they must understand what it can offer agriculture and the general public, and then they must become proactive in communicating the potential benefits of gene editing before this incredible tool ends up hobbled by negative connotations, as happened with GMO.

Traditionally, new crop varieties have been developed by crossing existing varieties and collecting the seeds of offspring which display the desired characteristics. But crossbreeding is slow and expensive, and the results are never guaranteed.

Starting in the 1930s, plant breeders began using mutagenesis in plant breeding. This involves exposing seeds and plants to gene-disrupting radiation or chemicals in the hopes of producing desirable mutations like bigger seeds, better oil or protein content, or other such factors. Again, however, success is random and time consuming.

The biotech revolution of the 1990s was supposed to end all that. Science now had a method of introducing a desired trait by inserting the relevant genes from a different species that already has that trait. This opened up a whole new world of herbicide tolerance, pest tolerance, drought tolerance, frost tolerance, salt tolerance and much, much more.

Sadly, most of the breeding effort went into herbicide tolerance and insect control (where farmers already had available management strategies) instead of qualities like drought tolerance. The reason was understandable. Biotech was hugely expensive, so companies focused research on the traits which offered the best and fastest returns. There was even more profit to be made if the genetic changes required the use of the products the company was already marketing.

But there’s another downside too. Many consumers fear transgenics.

A game changer

This is why gene editing is so promising. It does not require genes from other species, but neither is it random like regular crossbreeding or mutagenesis. Instead, gene editing entails a precise and surgical change in one or more genes to achieve a predetermined characteristic.

This is why gene editing gets described as a game changer for plant breeding.

But there is some learning that farmers must do to understand its full potential, starting with the fact that there are a number of gene editing processes, the most promising of which seems to be CRISPR-Cas9. (CRISPR stands for clustered regularly-interspaced short palindromic repeats, but don’t worry too much about the details just yet.)

In 2011, Jennifer Doudna at UC Berkeley and Emmanuelle Charpentier of Germany’s Max Planck Institute identified how bacteria protect themselves from viruses. They found bacteria store a small fragment of DNA from invading viruses in their own DNA. The advantage of this is, if a bacterium already has a DNA segment in its CRISPR that matches an attacking virus, the bacterium can rapidly mobilize an enzyme called Cas9 to cut up the attacking virus’s DNA.

Doudna and her colleagues believe this same process could be used in any organism, including plants and animals. By designing a specific segment of DNA and then either inserting it as a new section of DNA, or else using it to replace a defective DNA sequence, plant breeders can now design huge new opportunities.

TALENs and ZFN are two other older, patented processes which are also being used for gene editing but both are more complex.

The real beauty of gene editing is that the process mimics the way evolution happens naturally. The only difference is that rather than the change in the DNA happening randomly, as it does in nature, the change is specific and targeted. This means the outcome is already predicated.

As well, since the change happens in the DNA of the plant, the new attribute is passed on to future generations of the plant.

CRISPR-Cas9 technology has already been used successfully in the laboratory on important crops including wheat, rice, soybeans, canola, potatoes, sorghum, oranges, and tomatoes.

Gene editing research is also underway in Scotland to protect pigs from African swine fever, which attacks entire pig herds in Sub-Saharan Africa and Eastern Europe.

As well, gene editing has been used to prevent the growth of horns in dairy cattle, just as some breeds of beef cattle are polled.

The possibilities with gene editing are truly mind-boggling, even in humans. Theoretically, gene editing could inactivate a gene so viral infections such as herpes or AIDs would not occur. Or this technology might be used to correct a defective sequence of genes, as in muscular dystrophy, cystic fibrosis or Huntington’s. Or it may allow new drug discoveries by the insertion of new DNA coding into a gene.

But such advances do not happen overnight. It takes a lot of research to identify exactly which gene or multiples of genes are regulating a particular process and how the DNA could be changed to introduce a desired change. We are a long way from ending all inherited disease or having a pipeline of new drugs, pesticides, or even new crop varieties.

And we may never get there if this new technology runs into the same opposition as GMO. Farmers need to learn all the things that gene editing offers, and we need to get governments on side. (While CFIA does not consider gene editing to be transgenic, it is still regulating such modification under “novel trait” regulations.)

We will need technology like this to feed a growing population given the threat of climate change and the decline of our agricultural land base.

New names to follow

Below are a few of the companies in the lead with gene editing technology in agriculture:

Calyxt: This Minnesota company (previously Cellectis Plant Sciences Inc.) focuses on the creation of healthier crop products. It is currently working on developing high-oleic/low trans-fat soybean oil, cold storable potatoes, gluten-reduced wheat, and low saturated fat canola oils.

Partnering with Calyxt in gene editing and crop research and development are a number of major agricultural and food industry companies including Plant Bioscience Limited, U.K. Calyxt is also collaborating with with the University of Minnesota, Bayer Cropscience, Limagrain, Sesvanderhave, and INRA Science and Impact.

Previously, the company had signed agreements with Bayer Cropscience allowing Bayer to use the technology developed by this company for gene editing. Cellectis also had technology agreements with Monsanto and BASF.

Caribou Biosciences is a spinoff from the University of California, Berkeley and is led by Dr. Jennifer Doudna, one of the researchers who developed the CRISPR-Cas9 technology.

Caribou is working with DuPont/Pioneer Hi-Bred on developing drought-resistant corn and in creating hybrid wheat. Field trials of these crops could begin this spring, with commercial availability in five to 10 years.

Meanwhile, Purdue University researchers have successfully engineered rice that is five times better at surviving drought. They did this by altering plants so they overproduce a naturally occurring protein, which means they can survive severe drought without having an impact on plant growth under normal conditions.

As well, Recombinetics is focused on improving animal productivity as well as the health and welfare of livestock. They developed polled dairy cattle and are currently working to increase muscle mass in Brazilian cattle.

Canada comes second

Cibus, a San Diego-based plant breeding company has already commercialized a new herbicide-tolerant canola variety through gene editing. This new canola strain is resistant to a Group 2 imidazolinone and sulfonylurea herbicide. Unlike the RR and Liberty Link canola lines, this new canola strain is not considered as a GMO by the U.S., Canada, and Germany at this time, potentially opening up new markets and higher prices for growers.

Health Canada and CFIA have already reviewed this canola. On the Health Canada website the following statement is included in the review: “Health Canada is of the opinion the food derived from Cibus canola event 5715 is as safe and nutritious as food from current commercial canola varieties.”

Similarly, CFIA posted its review of this canola online with the findings “…CFIA has determined that canola event 5715 does not present altered environmental risk when compared to canola varieties that are currently grown in Canada.”

Now, a canola variety with the 5715 trait will be available for commercial production in the U.S. this year.

When Country Guide asked CFIA if this canola is registered for growing in Canada the spokesperson replied: “To date, no variety of canola with the 5715 trait has been registered to grow in Canada.”

To get a better understanding of gene editing there are a number of YouTube videos aimed at the general public on this subject including this one from the McGovern Institute for Brain Research at MIT.

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