Researchers from the University of Cambridge have laid the foundations for growing synthetic embryos that could develop a beating heart, gut and brain.
Story by Big Think
For over a century, scientists have dreamed of growing human organs sans humans. This technology could put an end to the scarcity of organs for transplants. But that’s just the tip of the iceberg. The capability to grow fully functional organs would revolutionize research. For example, scientists could observe mysterious biological processes, such as how human cells and organs develop a disease and respond (or fail to respond) to medication without involving human subjects.
Recently, a team of researchers from the University of Cambridge has laid the foundations not just for growing functional organs but functional synthetic embryos capable of developing a beating heart, gut, and brain. Their report was published in Nature.
The organoid revolution
In 1981, scientists discovered how to keep stem cells alive. This was a significant breakthrough, as stem cells have notoriously rigorous demands. Nevertheless, stem cells remained a relatively niche research area, mainly because scientists didn’t know how to convince the cells to turn into other cells.
Then, in 1987, scientists embedded isolated stem cells in a gelatinous protein mixture called Matrigel, which simulated the three-dimensional environment of animal tissue. The cells thrived, but they also did something remarkable: they created breast tissue capable of producing milk proteins. This was the first organoid — a clump of cells that behave and function like a real organ. The organoid revolution had begun, and it all started with a boob in Jello.
For the next 20 years, it was rare to find a scientist who identified as an “organoid researcher,” but there were many “stem cell researchers” who wanted to figure out how to turn stem cells into other cells. Eventually, they discovered the signals (called growth factors) that stem cells require to differentiate into other types of cells.
For a human embryo (and its organs) to develop successfully, there needs to be a “dialogue” between these three types of stem cells.
By the end of the 2000s, researchers began combining stem cells, Matrigel, and the newly characterized growth factors to create dozens of organoids, from liver organoids capable of producing the bile salts necessary for digesting fat to brain organoids with components that resemble eyes, the spinal cord, and arguably, the beginnings of sentience.
Synthetic embryos
Organoids possess an intrinsic flaw: they are organ-like. They share some characteristics with real organs, making them powerful tools for research. However, no one has found a way to create an organoid with all the characteristics and functions of a real organ. But Magdalena Żernicka-Goetz, a developmental biologist, might have set the foundation for that discovery.
Żernicka-Goetz hypothesized that organoids fail to develop into fully functional organs because organs develop as a collective. Organoid research often uses embryonic stem cells, which are the cells from which the developing organism is created. However, there are two other types of stem cells in an early embryo: stem cells that become the placenta and those that become the yolk sac (where the embryo grows and gets its nutrients in early development). For a human embryo (and its organs) to develop successfully, there needs to be a “dialogue” between these three types of stem cells. In other words, Żernicka-Goetz suspected the best way to grow a functional organoid was to produce a synthetic embryoid.
As described in the aforementioned Nature paper, Żernicka-Goetz and her team mimicked the embryonic environment by mixing these three types of stem cells from mice. Amazingly, the stem cells self-organized into structures and progressed through the successive developmental stages until they had beating hearts and the foundations of the brain.
“Our mouse embryo model not only develops a brain, but also a beating heart [and] all the components that go on to make up the body,” said Żernicka-Goetz. “It’s just unbelievable that we’ve got this far. This has been the dream of our community for years and major focus of our work for a decade and finally we’ve done it.”
If the methods developed by Żernicka-Goetz’s team are successful with human stem cells, scientists someday could use them to guide the development of synthetic organs for patients awaiting transplants. It also opens the door to studying how embryos develop during pregnancy.
This article originally appeared on Big Think, home of the brightest minds and biggest ideas of all time.
Insects for sale at a market in Cambodia.
The 21st century wave of entomophagy, or insect eating, first surged in the early 2010s, promoted by a research centre in Wageningen, a university in the Netherlands, conferences organized by the Food and Agriculture Organization of the United Nations, and enthusiastic endorsements by culinary adventurers and celebrities from Europeanized cultures. Headlines announced that two billion people around the world already ate insects, and that if everyone adopted entomophagy we could reduce greenhouse gases, mitigate climate change, and reign in profligate land and water use associated with industrial livestock production.
Furthermore, eating insects was better for human health than eating beef. If we were going to feed the estimated nine billion people with whom we will share the earth in 2050, we would need to make some radical changes in our agriculture and food systems. As one author proclaimed, entomophagy presented us with a last great chance to save the planet.
In 2010, in Kunming, a friend had served me deep-fried bamboo worms. I ate them to be polite. They tasted like French fries, but with heads.
The more recent data suggests that the number of people who eat insects in various forms, though sizeable, may be closer to several hundreds of millions. I knew that from several decades of international veterinary work. Sometimes, for me, insect eating has been simply a way of acknowledging cultural diversity. In 2010, in Kunming, a friend had served me deep-fried bamboo worms. I ate them to be polite. They tasted like French fries, but with heads. My friend said he preferred them chewier. I never thought about them much after that. I certainly had not thought about them as ingredients for human health.
Is consuming insects good for human health? Researchers over the past decade have begun to tease that apart. Some think it might not be useful to use the all-encompassing term insect at all; we don’t lump cows, pigs, chickens into one culinary category. Which insects are we talking about? What are they fed? Were they farmed or foraged? Which stages of the insects are we eating? Do we eat them directly or roasted and ground up?
The overall research indicates that, in general, the usual farmed insects (crickets, locusts, mealworms, soldier fly larvae) have high levels of protein and other important nutrients. If insects are foraged by small groups in Laos, they provide excellent food supplements. Large scale foraging in response to global markets can be incredibly destructive, but soldier fly larvae fed on food waste and used as a substitute for ground up anchovies for farmed fish (as Enterra Feed in Canada does) improves ecological sustainability.
Entomophagy alone might not save the planet, but it does give us an unprecedented opportunity to rethink how we produce and harvest protein.
The author enjoys insects from the Dong Makkhai forest-products market, just outside of Vientiane, the capital of the Lao Peoples Democratic Republic.
David Waltner-Toews
Between 1961 and 2018, world chicken production increased from 4 billion to 20 billion, pork from 200 million to over 100 billion pigs, human populations doubled from 3.5 billion to more than 7 billion, and life expectancy (on average) from 52 to 72 years. These dramatic increases in food production are the result of narrowly focused scientific studies, identifying specific nutrients, antibiotics, vaccines and genetics. What has been missing is any sort of peripheral vision: what are the unintended consequences of our narrowly defined success?
If we look more broadly, we can see that this narrowly defined success led to industrial farming, which caused wealth, health and labor inequities; polluted the environment; and created grounds for disease outbreaks. Recent generations of Europeanized people inherited the ideas of eating cows, pigs and chickens, along with their products, so we were focused only on growing them as efficiently as possible. With insects, we have an exciting chance to start from scratch. Because, for Europeanized people, insect eating is so strange, we are given the chance to reimagine our whole food system in consultation with local experts in Asia and Africa (many of them villagers), and to bring together the best of both locally adapted food production and global distribution.
For this to happen, we will need to change the dietary habits of the big meat eaters. How can we get accustomed to eating bugs? There’s no one answer, but there are a few ways. In many cases, insects are ground up and added as protein supplements to foods like crackers or bars. In certain restaurants, the chefs want you to get used to seeing the bugs as you eat them. At Le Feston Nu in Paris, the Arlo Guthrie look-alike bartender poured me a beer and brought out five small plates, each featuring a different insect in a nest of figs, sun-dried tomatoes, raisins, and chopped dried tropical fruits: buffalo worms, crickets, large grasshoppers (all just crunchy and no strong flavour, maybe a little nutty), small black ants (sour bite), and fat grubs with a beak, which I later identified as palm weevil larvae, tasting a bit like dried figs.
Some entomophagy advertising has used esthetically pleasing presentations in classy restaurants. In London, at the Archipelago restaurant, I dined on Summer Nights (pan fried chermoula crickets, quinoa, spinach and dried fruit), Love-Bug Salad (baby greens with an accompanying dish of zingy, crunchy mealworms fried in olive oil, chilis, lemon grass, and garlic), Bushman’s Cavi-Err (caramel mealworms, bilinis, coconut cream and vodka jelly), and Medieaval Hive (brown butter ice cream, honey and butter caramel sauce and a baby bee drone).
The Archipelago restaurant in London serves up a Love-Bug Salad: baby greens with an accompanying dish of zingy, crunchy mealworms fried in olive oil, chilis, lemon grass, and garlic.
David Waltner-Toews
Some chefs, like Tokyo-based Shoichi Uchiyama, try to entice people with sidewalk cooking lessons. Uchiyama's menu included hornet larvae, silkworm pupae, and silkworms. The silkworm pupae were white and pink and yellow. We snipped off the ends and the larvae dropped out. My friend Zen Kawabata roasted them in a small pan over a camp stove in the street to get the "chaff" off. We made tea from the feces of worms that had fed on cherry blossoms—the tea smelled of the blossoms. One of Uchiyama-san’s assistants made noodles from buckwheat dough that included powdered whole bees.
At a book reading in a Tokyo bookstore, someone handed me a copy of the Japanese celebrity scandal magazine Friday, opened to an article celebrating the “charms of insect eating.” In a photo, scantily-clad girls were drinking vodka and nibbling giant water bugs dubbed as toe-biters, along with pickled and fried locusts and butterfly larvae. If celebrities embraced bug-eating, others might follow. When asked to prepare an article on entomophagy for the high fashion Sorbet Magazine, I started by describing a clip of Nicole Kidman delicately snacking on insects.
Taking a page from the success story of MacDonald’s, we might consider targeting children and school lunches. Kids don’t lug around the same dietary baggage as the grownups, and they can carry forward new eating habits for the long term. When I offered roasted crickets to my grandchildren, they scarfed them down. I asked my five-year-old granddaughter what she thought: she preferred the mealworms to the crickets – they didn’t have legs that caught in her teeth.
Entomo Farms in Ontario, the province where I live, was described in 2015 by Canadian Business magazine as North America’s largest supplier of edible insects for human consumption. When visiting, I popped some of their roasted crickets into my mouth. They were crunchy, a little nutty. Nothing to get squeamish over. Perhaps the human consumption is indeed growing—my wife, at least, has joined me in my entomophagy adventures. When we celebrated our wedding anniversary at the Public Bar and Restaurant in Brisbane, Australia, the “Kang Kong Worms” and “Salmon, Manuka Honey, and Black Ants” seemed almost normal. Of course, the champagne helped.
In this episode of Making Sense of Science, my guest is Raina Plowright, a leading researcher when it comes to how and why viruses sometimes jump from bats to humans.
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Raina Plowright, a disease ecologist at Cornell University, is taking blood and urine samples from hundreds of animals and using GPS tags to follow their movement.
Kelly Gorham