Tag Archives: crispr-Cas9

Modernize or Die: Bio-Engineered Food

China is betting that CRISP technology*can transform the country’s food supply.  China also expanded its efforts beyond its borders in 2017, when the state-owned company ChemChina bought Switzerland-based Syngenta—one of the world’s four largest agribusinesses, which has a large R&D team working with CRISPR—for $43 billion. That was the most China has ever spent on acquiring a foreign company, and it created an intimate relationship between government, industry, and academia—a “sort of a ménage à trois” that ultimately could funnel intellectual property from university labs into the company, says plant geneticist Zachary Lippman of Cold Spring Harbor Laboratory in New York.

Chinese leaders “want to strategically invest in genome editing, and [by that] I mean, catch up,” says Zhang Bei, who heads a team of 50 scientists at the Syngenta Beijing Innovation Center…China may one day need CRISPR-modified plants to provide enough food for its massive population….    China needs to resolve how it will regulate CRISPR-engineered crops—a divisive issue in many countries. In a 2018 decision that rocked big agriculture, a European court ruled that such crops are genetically modified organisms (GMOs) that need strict regulation. In contrast, the U.S. Department of Agriculture (USDA) exempts genome-edited plants from regulations covering GMOs as long as they were produced not by transferring DNA from other species, but by inducing mutations that could have occurred naturally or through conventional breeding.  Chinese consumers are wary of GM food. The country strictly limits the import of GM crops, and the only GM food it grows are papayas for domestic consumption. But for CRISPR, many plant researchers around assume China will follow in the United States’s footsteps…

For Corteva, Syngenta, and the other two big ag companies—BASF and Bayer (which acquired Monsanto last year)—the long game is to use CRISPR to develop better versions of their serious moneymakers, the “elite” varieties of a wide range of crops that have big commercial markets. They sell dozens of kinds of elite corn seeds—for example, inbred strains that consistently have high yields or reliable resistance to herbicides. Creating the genetic purity needed for an elite variety typically takes traditional breeding of many generations of plants, and CRISPR is seen as the cleanest way to improve them quickly. The earlier methods of engineering a plant can lead to unwanted genomic changes that must be laboriously culled…

Syngenta sees CRISPR-modified corn as a big opportunity in China, which grows more hectares of corn than any other crop. Yields per hectare are only 60% of those in the United States because corn ear worms often weaken Chinese crops. A fungus thrives in the weakened plants, producing a toxin that makes the resultant ears unfit for animal feed. As a result, China must import a great deal of corn. (According to USDA, 82% of U.S.-grown corn has been engineered to have a bacterial gene that makes it resistant to ear worms.)…“Syngenta is putting a lot of emphasis to grow in China to become the leading seed company. The China market as a whole, if it modernizes as the U.S. has modernized, can be as big as the U.S. market.”

Jon Cohen, To feed its 1.4 billion, China bets big on genome editing of crops, Science Magazine, Aug. 2, 2019

* Genome editing (also called gene editing) is a group of technologies that give scientists the ability to change an organism’s DNA. These technologies allow genetic material to be added, removed, or altered at particular locations in the genome. Several approaches to genome editing have been developed. A recent one is known as CRISPR-Cas9.

Eradicate Mosquitoes Forever: Gene Drives

The mosquitoes are being fitted with a piece of dna called a gene drive. Unlike the genes introduced into run-of-the-mill genetically modified organisms, gene drives do not just sit still once inserted into a chromosome. They actively spread themselves, thereby reaching more and more of the population with each generation. If their effect is damaging, they could in principle wipe out whole species.. If gene drives were to condemn to a similar fate the mosquitoes that spread malaria, a second of humankind’s great scourges might be consigned to history.

Gene drives can in principle be used against any creatures which reproduce sexually with short generations and aren’t too rooted to a single spot. The insects that spread leishmaniasis, Chagas disease, dengue fever, chikungunya, trypanosomiasis and Zika could all be potential targets. So could creatures which harm only humankind’s dominion, not people themselves. Biologists at the University of California, San Diego, have developed a gene-drive system for Drosophila suzukii, an Asian fruitfly which, as an invasive species, damages berry and fruit crops in America and Europe. Island Conservation, an international environmental ngo, thinks gene drives could offer a humane and effective way of reversing the damage done by invasive species such as rats and stoats to native ecosystems in New Zealand and Hawaii.

Such critics fear that the laudable aim of vastly reducing deaths from malaria—which the World Health Organisation puts at 445,000 a year, most of them children—will open the door to the use of gene drives for far less clear-cut benefits in ways that will entrench some interests, such as those of industrial farmers, at the expense of others. They also point to possible military applications: gene drives could in principle make creatures that used not to spread disease more dangerous… The ability to remove species by fiat—in effect, to get them to remove themselves—is, like the prospect of making new species from scratch, a power that goes beyond the past ambit of humankind.

Gene drives based on crispr-Cas9 could easily be engineered to target specific bits of the chromosome and insert themselves seamlessly into the gap, thus ensuring that every gamete gets a copy . By 2016, gene drives had been created in yeast, fruitflies and two species of mosquito. In work published in the journal Nature Biotechnology in September, Andrea Crisanti, Mr Burt and colleagues at Imperial showed that one of their gene drives could drive a small, caged population of the mosquito Anopheles gambiae to extinction—the first time a gene drive had shown itself capable of doing this. The next step is to try this in a larger caged population.

There are also worries about how gene drives might be used to create a weapon. …The need to find ways to guard against such attacks is one of the reasons that the Pentagon’s Defence Advanced Research Projects Agency (darpa) gives for its work on gene drives. Renee Wegrzyn, programme manager for darpa’s “Safe Genes” project, says the work is to prevent “technological surprise”, whether in the form of an unintended consequence or nefarious use. One of the academic teams she funds has made progress in developing anti-crispr enzyme systems that one day might be able to inhibit a drive’s operation.

Oversight needs not just to bring together a range of government agencies; it requires co-operation between governments, too. The Cartagena Protocol on Biosafety, which entered into force under the un Convention on Biological Diversity (cbd) in 2003, provides controls on the transfer of genetically modified organisms. But how it applies to gene drives is unclear—and besides, America has never ratified the convention. An attempt to ban gene-drive research through the cbd, which was backed by the etc Group and other ngos, failed at the convention’s biennial meeting in Cancún in 2016…Like the reintroduction of vanished species advocated by the rewilding movement, gene-drive technology will provide new arenas for the fight between those who wish to defend nature and those who wish to tame it.

Excertps from Gene Drives: Extinction on Demand, Economist, Nov. 10, 2018, at 24