Tag Archives: CRISPR-Cas9 gene-editing tool on coral

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.

Assisted Evolution: Engineering Coral Reefs

Imagine ecologists cultivating whole new breeds of trees to restock a devastated wilderness…. Coral conservation has traditionally focused on minimizing damage from insults such as water pollution, invasive starfish, and destructive fishing or tourism. In the Caribbean, some conservationists have worked to “replant” damaged coral. But Gates and Van Oppen [two scientists]  have something more intrusive in mind. They want to try to alter the genetics of coral or the microbes that live on it. They dubb the effort “assisted evolution.”

Coral’s most remarkable characteristic—being an animal that is part plant—is also its Achilles’ heel in a hotter world. Normally, coral polyps—the individual coral organisms, which resemble a sea anemone the size of a pinhead—live in harmony with their algal partners, which help feed the polyps and give corals their bright colors. But during heat waves, the relationship sours. Overheated polyps perceive the algae as an irritant and eject them like unwanted squatters. The coral is left bleached, bone-white and starving. If the heat persists, the coral won’t take in new algae and can die.  The bond between coral and algae is complicated, however, and still not fully understood. Just 25 years ago, for example, researchers believed that coral housed just one variety of symbiotic algae. Now, they have identified hundreds. And they are just beginning to examine the role played by the coral’s microbiome, the menagerie of bacteria that inhabit a coral polyp.

Coral bleaching right.

But the complexity also offers multiple paths for scientists trying to forge a less fragile bond between coral and algae. Today, four major lines of research exist: One involves cross-breeding corals to create heat-tolerant varieties, either by mixing strains within a species or by crossing two species that would not normally interbreed. The second enlists genetic engineering techniques to tweak coral or algae. A third tries to rapidly evolve hardier strains of coral and algae by rearing them for generations in overheated lab conditions. A fourth approach, the newest, seeks to manipulate the coral’s microbiome…

In 2018, Cleves [scientist] became the first to report successfully using the CRISPR-Cas9 gene-editing tool on coral. CRISPR is often touted as a method for making genetically modified species. But Cleves says he isn’t interested in creating new kinds of coral. Rather, he sees CRISPR as a tool for deciphering the inner workings of coral DNA by knocking out, or disabling, genes one by one. He hopes to identify genes that might serve as “master switches” controlling how coral copes with heat and stress—knowledge that could help researchers quickly identify corals in the wild or in the laboratory that are already adapted to heat.

Either way, such efforts to re-engineer coral reefs make people such as David Wachenfeld, chief scientist for the Great Barrier Reef Marine Park Authority here, uneasy. The authority is supposed to protect the reef and regulate activities there. In the past, that meant a hands-off approach. Now, he concedes that “it is almost inconceivable that we’re not going to need these tools.” But, he adds, “That doesn’t mean I’m happy about any of this. This is crisis management.”

He ticks off a list of potential difficulties. Scientists focused on breeding heat-loving coral have to avoid weakening other key traits, such as coping with cold. Introducing a new coral on the scale needed to make a dent on a network of 2900 reefs spanning an area half the size of Texas is a daunting challenge. Even in its damaged state, the Great Barrier Reef still contains hundreds of millions of corals—enough to swamp the genetic impact of new coral species…

Could some kind of “super coral,” as some researchers have dubbed them, also run amok in delicate coral ecosystems.

Excerpts from  The Reef Builders, Science, Mar. 22, 2019