Just Say No to Editing Human Embryos for Reproduction
BIG QUESTION OF THE MONTH: Should we use CRISPR, the new technique that enables precise DNA editing, to change the genes of human embryos to eradicate disease – or even to enhance desirable traits? LeapsMag invited three leading experts to weigh in.
Over the last few decades, the international community has issued several bioethical guidelines and legally binding documents, ranging from UN Declarations to regional charters to national legislation, about editing the human germline--the DNA that is passed down to future generations. There was a broad consensus that modifications should be prohibited. But now that CRISPR-cas9 and related methods of gene editing are taking the world by storm, that stance is softening--and so far, no thorough public discussion has emerged.
There is broad agreement in the scientific and ethics community that germline gene editing must not be clinically applied unless safety concerns are resolved. Predicting that safety issues will indeed be minimized, the National Academy of Sciences issued a report this past February that sets up several procedural norms. These may serve as guidelines for future implementation of human embryo editing, among them that there are no "reasonable alternatives," a condition that is left deliberately vague.
I regard the conditional embrace of germline gene editing as a grave mistake: It is a dramatic break with the previous idea of a ban, departing also from the moratorium that the UNESCO International Bioethics Committee had recommended in 2015. But in a startling move, the Academy already set the next post, recommending "that genome editing for purposes other than treatment or prevention of disease and disability should not proceed at this time" (my emphasis). It recommended public discussions, but without spelling out its own role in facilitating them.
"The international community should explicitly ban embryo gene editing as a method of human reproduction."
To proceed ethically, I argue that the international community, through the United Nations and in line with the ban on human reproductive cloning, should explicitly ban embryo gene editing as a method of human reproduction. Together with guidelines adjusted for non-reproductive and non-human applications, a prohibition would ensure two important results: First, that non-reproductive human embryo research could be pursued in a responsible way in those countries that allow for it, and second, that individual scientists, public research institutes, and private companies would know the moral limit of possible research.
Basic human embryo research is required, scientists argue, to better understand genetic diseases and early human development. I do not question this, and I am convinced that existing guidelines can be adjusted to meet the moral requirements in this area. Millions of people may benefit from different non-reproductive pathways of gene editing. Germline gene editing, in contrast, does not offer any resolutions to global or local health problems – and that alone raises many concerns about the current state of scientific research.
I support a ban because germline gene editing for reproductive purposes concerns more than safety. The genetic modification of a human being is irreversible and unpredictable in its epigenetic, personal, and social effects. It concerns the rights of children; it exposes persons with disabilities to social stigmatization; it contradicts the global justice agenda with respect to healthcare; and it infringes upon the rights to freedom and well-being of future persons.
"Reproductive germline gene editing directly violates the rights of individual future person."
Apart from questions of justice, reproductive germline gene editing may well increase the stigmatization of persons with disabilities. I want to emphasize here, however, that it directly violates the rights of individual future persons, namely a future child's right to genetic integrity, to freedom, and potentially to well-being, all guaranteed in different UN Declarations of Human Rights. For all these reasons, it is an unacceptable path forward.
The way the discussion has been framed so far is very different from my perspective that situates germline gene editing in the broader framework of human rights and responsibilities. In short, many others never questioned the goal but instead focused on the unintentional side-effects of an otherwise beneficial technique for human reproduction. Some scientists see germline gene editing as an alternative to embryo selection via Preimplantation Genetic Diagnosis (PGD), a procedure in which multiple embryos are tested to find out which ones carry disease-causing mutations. Others see it as the first step to human enhancement.
Some physicians argue that in the field of assisted reproduction, not every couple is comfortable with embryo selection via PGD, because potentially, unchosen embryos are discarded. Germline gene editing offers them an alternative. It is rarely mentioned, however, that germline gene editing would most likely still require PGD as a control of the procedure (though without the purpose of selection), and that prenatal genetic diagnosis would also be highly recommended. In other words, germline gene editing would not replace existing protocols but rather change their purpose, and it would also not necessarily reduce the number of embryos needed for assisted reproduction.
In some (rare) cases, PGD is not an option, because in the couples' condition, all embryos will be affected. One current option to avoid transmitting genetic traits is to use a donor sperm or egg, though the resulting child would not be genetically related to one parent. If these parents had an obligation, as some proponents argue, to secure the health of their offspring (an argument that I do not follow), then procreation with sperm or egg donation would even be morally required, as this is the safest procedure to erase a given genetic trait.
There are no therapeutic scenarios that exclusively require reproductive gene editing even if one accepts the right to reproductive autonomy. The fact is that couples who rightly wish to secure and protect the health of their future children can be offered medical alternatives in all cases. However, this requires considering sperm or egg donation as the safest and most reasonable option – the condition the NAS Report has set.
Scientists in favor of germline gene editing argue against this: the desire for genetic kinship, they say, is a legitimate expression of a couple's reproductive freedom, and germline gene editing offers them an alternative to have a healthy child. In the future, proponents say, these (very few) couples who wish for genetically related offspring will be faced with the dilemma of either accepting the transmission of a genetic health risk to their children or weighing the benefits and risks of gene editing.
But here is a blind spot in the whole discussion.
Many scientists and some bioethicists think that reproductive freedom includes the right to a genetically related child. But even if we were to presuppose such a right, it is not absolute in the context of assisted reproduction. Although sperm or egg donation may be undesirable for some couples, the moral question of responsibility does not disappear with their reproductive rights. At a minimum, the future child's rights must be considered, and these rights go further than their health rights.
It is puzzling that in claiming their own reproductive freedom, couples would need to ignore their children's and possibly grandchildren's future freedom – including the constraints resulting from being monitored over the course of their lives and the indirect constraints of the children's own right to reproductive freedom. From a medical standpoint, it would be highly recommended for them, too, to have children through assisted reproduction. This distinguishes germline gene editing from any other procedure of assisted reproduction: we need the data from the second and third generations to see whether the method is safe and efficacious. Whose reproductive freedom should count, the parents' or the future children's?
But for now, the question of parental rights may well divert the discussion from the question of responsible gene editing research; its conditions and structures require urgent evaluation and adjustment to guide international research groups. I am concerned that we are in the process of developing a new technology that has tremendous potential and ramifications – but without having considered the ethical framework for a responsible path forward.
Editor's Note: Check out the viewpoints expressing enthusiastic support and mild curiosity.
Autonomous, indoor farming gives a boost to crops
The glass-encased cabinet looks like a display meant to hold reasonably priced watches, or drugstore beauty creams shipped from France. But instead of this stagnant merchandise, each of its five shelves is overgrown with leaves — moss-soft pea sprouts, spikes of Lolla rosa lettuces, pale bok choy, dark kale, purple basil or red-veined sorrel or green wisps of dill. The glass structure isn’t a cabinet, but rather a “micro farm.”
The gadget is on display at the Richmond, Virginia headquarters of Babylon Micro-Farms, a company that aims to make indoor farming in the U.S. more accessible and sustainable. Babylon’s soilless hydroponic growing system, which feeds plants via nutrient-enriched water, allows chefs on cruise ships, cafeterias and elsewhere to provide home-grown produce to patrons, just seconds after it’s harvested. Currently, there are over 200 functioning systems, either sold or leased to customers, and more of them are on the way.
The chef-farmers choose from among 45 types of herb and leafy-greens seeds, plop them into grow trays, and a few weeks later they pick and serve. While success is predicated on at least a small amount of these humans’ care, the systems are autonomously surveilled round-the-clock from Babylon’s base of operations. And artificial intelligence is helping to run the show.
Babylon piloted the use of specialized cameras that take pictures in different spectrums to gather some less-obvious visual data about plants’ wellbeing and alert people if something seems off.
Imagine consistently perfect greens and tomatoes and strawberries, grown hyper-locally, using less water, without chemicals or environmental contaminants. This is the hefty promise of controlled environment agriculture (CEA) — basically, indoor farms that can be hydroponic, aeroponic (plant roots are suspended and fed through misting), or aquaponic (where fish play a role in fertilizing vegetables). But whether they grow 4,160 leafy-green servings per year, like one Babylon farm, or millions of servings, like some of the large, centralized facilities starting to supply supermarkets across the U.S., they seek to minimize failure as much as possible.
Babylon’s soilless hydroponic growing system
Courtesy Babylon Micro-Farms
Here, AI is starting to play a pivotal role. CEA growers use it to help “make sense of what’s happening” to the plants in their care, says Scott Lowman, vice president of applied research at the Institute for Advanced Learning and Research (IALR) in Virginia, a state that’s investing heavily in CEA companies. And although these companies say they’re not aiming for a future with zero human employees, AI is certainly poised to take a lot of human farming intervention out of the equation — for better and worse.
Most of these companies are compiling their own data sets to identify anything that might block the success of their systems. Babylon had already integrated sensor data into its farms to measure heat and humidity, the nutrient content of water, and the amount of light plants receive. Last year, they got a National Science Foundation grant that allowed them to pilot the use of specialized cameras that take pictures in different spectrums to gather some less-obvious visual data about plants’ wellbeing and alert people if something seems off. “Will this plant be healthy tomorrow? Are there things…that the human eye can't see that the plant starts expressing?” says Amandeep Ratte, the company’s head of data science. “If our system can say, Hey, this plant is unhealthy, we can reach out to [users] preemptively about what they’re doing wrong, or is there a disease at the farm?” Ratte says. The earlier the better, to avoid crop failures.
Natural light accounts for 70 percent of Greenswell Growers’ energy use on a sunny day.
Courtesy Greenswell Growers
IALR’s Lowman says that other CEA companies are developing their AI systems to account for the different crops they grow — lettuces come in all shapes and sizes, after all, and each has different growing needs than, for example, tomatoes. The ways they run their operations differs also. Babylon is unusual in its decentralized structure. But centralized growing systems with one main location have variabilities, too. AeroFarms, which recently declared bankruptcy but will continue to run its 140,000-square foot vertical operation in Danville, Virginia, is entirely enclosed and reliant on the intense violet glow of grow lights to produce microgreens.
Different companies have different data needs. What data is essential to AeroFarms isn’t quite the same as for Greenswell Growers located in Goochland County, Virginia. Raising four kinds of lettuce in a 77,000-square-foot automated hydroponic greenhouse, the vagaries of naturally available light, which accounts for 70 percent of Greenswell’s energy use on a sunny day, affect operations. Their tech needs to account for “outside weather impacts,” says president Carl Gupton. “What adjustments do we have to make inside of the greenhouse to offset what's going on outside environmentally, to give that plant optimal conditions? When it's 85 percent humidity outside, the system needs to do X, Y and Z to get the conditions that we want inside.”
AI will help identify diseases, as well as when a plant is thirsty or overly hydrated, when it needs more or less calcium, phosphorous, nitrogen.
Nevertheless, every CEA system has the same core needs — consistent yield of high quality crops to keep up year-round supply to customers. Additionally, “Everybody’s got the same set of problems,” Gupton says. Pests may come into a facility with seeds. A disease called pythium, one of the most common in CEA, can damage plant roots. “Then you have root disease pressures that can also come internally — a change in [growing] substrate can change the way the plant performs,” Gupton says.
AI will help identify diseases, as well as when a plant is thirsty or overly hydrated, when it needs more or less calcium, phosphorous, nitrogen. So, while companies amass their own hyper-specific data sets, Lowman foresees a time within the next decade “when there will be some type of [open-source] database that has the most common types of plant stress identified” that growers will be able to tap into. Such databases will “create a community and move the science forward,” says Lowman.
In fact, IALR is working on assembling images for just such a database now. On so-called “smart tables” inside an Institute lab, a team is growing greens and subjects them to various stressors. Then, they’re administering treatments while taking images of every plant every 15 minutes, says Lowman. Some experiments generate 80,000 images; the challenge lies in analyzing and annotating the vast trove of them, marking each one to reflect outcome—for example increasing the phosphate delivery and the plant’s response to it. Eventually, they’ll be fed into AI systems to help them learn.
For all the enthusiasm surrounding this technology, it’s not without downsides. Training just one AI system can emit over 250,000 pounds of carbon dioxide, according to MIT Technology Review. AI could also be used “to enhance environmental benefit for CEA and optimize [its] energy consumption,” says Rozita Dara, a computer science professor at the University of Guelph in Canada, specializing in AI and data governance, “but we first need to collect data to measure [it].”
The chef-farmers can choose from 45 types of herb and leafy-greens seeds.
Courtesy Babylon Micro-Farms
Any system connected to the Internet of Things is also vulnerable to hacking; if CEA grows to the point where “there are many of these similar farms, and you're depending on feeding a population based on those, it would be quite scary,” Dara says. And there are privacy concerns, too, in systems where imaging is happening constantly. It’s partly for this reason, says Babylon’s Ratte, that the company’s in-farm cameras all “face down into the trays, so the only thing [visible] is pictures of plants.”
Tweaks to improve AI for CEA are happening all the time. Greenswell made its first harvest in 2022 and now has annual data points they can use to start making more intelligent choices about how to feed, water, and supply light to plants, says Gupton. Ratte says he’s confident Babylon’s system can already “get our customers reliable harvests. But in terms of how far we have to go, it's a different problem,” he says. For example, if AI could detect whether the farm is mostly empty—meaning the farm’s user hasn’t planted a new crop of greens—it can alert Babylon to check “what's going on with engagement with this user?” Ratte says. “Do they need more training? Did the main person responsible for the farm quit?”
Lowman says more automation is coming, offering greater ability for systems to identify problems and mitigate them on the spot. “We still have to develop datasets that are specific, so you can have a very clear control plan, [because] artificial intelligence is only as smart as what we tell it, and in plant science, there's so much variation,” he says. He believes AI’s next level will be “looking at those first early days of plant growth: when the seed germinates, how fast it germinates, what it looks like when it germinates.” Imaging all that and pairing it with AI, “can be a really powerful tool, for sure.”
Scientists make progress with growing organs for transplants
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.