China vs. the West: Who Will Lead the Way in Embryo Editing Research?
Junjiu Huang and his team performed a miracle. A few miracles, actually. The researchers at Sun Yat-sen University in Guangzhou, China used the precise new DNA editing tool called CRISPR-CAS9 to edit a human embryo, replacing a single base. In doing so, they edited out beta-thalassemia, a blood disorder that reduces the production of hemoglobin, which can result in pale skin, fatigue, higher risk of blood clots, and other symptoms.
The race is on, and it's one everyone is going to try to win.
Huang's group, which did not respond to an email requesting comment for this story, injected 86 embryos and observed them for 48 hours. After that period -- a time long enough for CRISPR to split the DNA, other molecules to replace the base, and the embryos to grow to eight cells -- they tested 54 of the 71 that survived. Of those, only a few had the replacement base, according to a report of the study published in Protein & Cell. The experiment stopped there as the embryos, which had been acquired from local fertility clinics, were non-viable and not implanted.
But procreation was not the point. Far from it, in fact. The point was to demonstrate that it could be done, that in some far off (or not so far off) future, doctors could use CRISPR to eliminate diseases like Tay-Sachs, Huntington's, and cystic fibrosis that are caused by genetic mutations. Going a step further, perhaps they could eventually even tailor embryos that will develop into adults with specific traits like height and IQ.
Experts agree that we are far from that point, years if not decades away from leveraging CRISPR to cure diseases and decades if not centuries from being able to build designer babies. In that frame, Huang's achievement is just a small step, a blip on the timeline of human achievement. But seen in another light, it's yet another sign that we need to start talking about DNA modification now, establishing protocols, procedures, and plans that guide the subject before we get so far down the road that momentum is impossible to stop.
"The Chinese generally don't have the religious objections to embryo research that have held back research in the West."
It's essential to do so now because the idea of DNA modification -- a realization that humanity can control its evolution -- is compelling and attractive. Imagine a world where doctors and scientists could get rid of disease before it begins or ensure a baby would arrive with an Einstein-level IQ. That's intriguing, and also terrifying. What are the rules? How do we know when to stop? What guides the process? And how can we prevent mistakes or unwanted mutations? To borrow from another famous quotation, with great power comes great responsibility.
These aren't questions for Huang and the Chinese scientific community alone. A team from Oregon recently edited viable human embryos, eliminating a mutation that can lead to heart failure while preventing any unintended consequences. Just as importantly, every embryo they edited produced the intended genetic changes, a vital step since a partial success rate, known as mosaicism, could have devastating consequences to a future child.
In London at the Francis Crick Institute, researcher Kathy Niakan used CRISPR-CAS9 to "turn off" a gene that produces the protein OCT4. Without the protein, the fertilized egg could not produce a blastocyst, which is a key structure in early mammalian development that gives rise to an embryo and placenta. The recent study wasn't designed to go further, but the use of CRISPR was important. "One way to find out what a gene does in the developing embryo is to see what happens when it isn't working," said Dr. Niakan, who was the first scientist in the world to be granted regulatory approval to edit the genes of a human embryo for research. "Now that we have demonstrated an efficient way of doing this, we hope that other scientists will use it to find out the roles of other genes. If we knew the key genes that embryos need to develop successfully, we could improve IVF treatments and understand some causes of pregnancy failure. It may take many years to achieve such an understanding. Our study is just the first step."
The point is, CRISPR is here and it's not going anywhere. Scientists will continue to use it to learn about how humans develop. Yet different rules regarding CRISPR and embryo research in countries around the world will impact who gets there first. "I've heard the U.S.-China gene editing research parallel paths as Sputnik 2.0," said Kevin Doxzen, Science Communications Specialist at the University of California, Berkeley's Innovative Genomics Institute. The race is on, and it's one everyone is going to try to win.
Based on number of researchers and ease of regulations, the Chinese are the favorites to advance the science the furthest, the fastest.
Based on number of researchers and ease of regulations, the Chinese are the favorites to advance the science the furthest, the fastest. "The Chinese generally don't have the religious (predominantly Christian) or moral objections to embryo research that have held back research in the West," said Dr. Julian Savulescu, the Uehiro Professor of Practical Ethics and Director of the Oxford Martin Programme on Collective Responsibility for Infectious Disease at the University of Oxford. "This kind of research should be done, with the right sort of ethical oversight. The concern over China leading the way is that institutional oversight mechanisms are probably not as developed as in the West but so far, there is no evidence of breaches in standards of research ethics around the published research."
Or, put another way by bioethicist Dr. Arthur Caplan, founding director of NYU Langone Health's Division of Medical Ethics: "The Chinese, because they don't care and don't have moral reservations about embryo work, are doing what they want." This lack of aversion to working with embryos manifests itself in a couple of ways. The absence of moral qualms is one. Funding is another. Huang's study, and others like it, receive funding from the government. His, for example, was supported by two grants from the National Basic Research Program and three from the National Natural Science Foundation of China.
The U.S., on the other hand, bans any federal funding for research using human embryos. A law passed in 1996 states that federal dollars can't be used for: "research in which a human embryo or embryos are destroyed, discarded, or knowingly subjected to risk of injury or death greater than that allowed for research on fetuses." This restriction can shift incentives as many private institutions or commercial enterprises may have financial motivations or other goals beyond furthering basic research for the sake of general knowledge.
Embryo gene modification recently performed in the U.K. would merit 15 years in prison in Australia.
The embryo research ban is even more strict elsewhere. The Oviedo Convention, enacted in 1997, effectively prohibits germline engineering in members of the European Union. "In Italy, you can't destroy an embryo for any reason," said Alessandro Bertero, a postdoctoral fellow at the University of Washington's Department of Pathology who used to study in Italy. "It's illegal, and you'll go to jail." Later, Bertero was one of the researchers who worked with Dr. Niakan in London, an investigation that was allowed by the UK's Human Fertilisation and Embryology Authority. (In Australia, Niakan and her colleagues would face 15 years in jail due to the 2002 Prohibition of Human Cloning Act, which prohibits altering the genomes of embryonic cells.)
Despite the moral and legal reservations in the Western world, every person I spoke with for this story believed that better, more advanced studies and learning is happening in the U.S. and Europe. "The best studies in my opinion are from the labs in California and Oregon," Bertero said. "The quality of the work [in the Chinese study] – not being critical, but to be scientifically critical -- was just quick and dirty. It was, 'Let's just show that we have done it and get it out.' That doesn't mean that the quality of the work was good."
"If the Chinese or someone else starts beating our brains out, we're not going to want to stand by idly and not do these things."
How long that remains the case, however, is an open question. A significant number of groups in China are working on germline editing in human embryos. The concern is that the Chinese will emerge as a leader sooner rather than later because they can do research with embryos more easily than their Western counterparts.
For Caplan, the NYU professor, the embryo ban in the U.S. isn't based on science; it's rooted in something else. "It's 96 percent political," he said, laughing. "It has basically ground to a halt because no one wants to see repercussions take place if federal funding is involved. The NIH isn't involved. And they won't be."
What, in his mind, would get Americans to start realizing the benefits that embryo research would provide? "The perception that other countries were moving quickly to get the advantages of CRISPR and other gene modification techniques, finding more industrial and more medical purposes," he said. "If the Chinese or someone else starts beating our brains out, we're not going to want to stand by idly and not do these things."
Doing so would involve difficult conversations about the role of embryos in research. But these are philosophical questions that need to be approached at some point. From a U.S. perspective, doing so sooner while the American scientists still hold the technological and informational edge, is vital. Ignoring the issue doesn't make it go away.
Experts think a few changes should be made. The ban on federal funding should be lifted. Scientists and regulators should push for things like allowing federal funds to be used for the creation of new embryos for research purposes and the use of spare IVF embryos for research when the embryo would not be implanted into a woman. (Privately funded scientists can proceed in states that encourage embryonic stem cell research, like New York, New Jersey, and California, but not in restrictive ones like Louisiana and South Dakota, which prohibit creating or destroying embryos for research.) Policymakers could ban reproductive gene editing for now but look at it again after a certain period. A highly anticipated report issued earlier this year from an international guidance committee left the door open to eventual clinical trials with edited embryos. As of now, however, Congress will not allow the Food and Drug Administration to consider such trials. This is the future and it's the scientific community's responsibility to develop the ethical framework now.
"The US and Europe have the technological history and capacity to lead this research and should do so, ethically. We ought to be revising our laws and ethical guidelines to facilitate this kind of research," Professor Savulescu said. "But the challenge is to think constructively and ethically about this new technology, and to be leaders, not followers."
Two-and-a-half year-old Huckleberry, a blue merle Australian shepherd, pulls hard at her leash; her yelps can be heard by skiers and boarders high above on the chairlift that carries them over the ski patrol hut to the top of the mountain. Huckleberry is an avalanche rescue dog — or avy dog, for short. She lives and works with her owner and handler, a ski patroller at Breckenridge Ski Resort in Colorado. As she watches the trainer play a game of hide-and-seek with six-month-old Lume, a golden retriever and avy dog-in-training, Huckleberry continues to strain on her leash; she loves the game. Hide-and-seek is one of the key training methods for teaching avy dogs the rescue skills they need to find someone caught in an avalanche — skier, snowmobiler, hiker, climber.
Lume’s owner waves a T-shirt in front of the puppy. While another patroller holds him back, Lume’s owner runs away and hides. About a minute later — after a lot of barking — Lume is released and commanded to “search.” He springs free, running around the hut to find his owner who reacts with a great amount of excitement and fanfare. Lume’s scent training will continue for the rest of the ski season (Breckenridge plans operating through May or as long as weather permits) and through the off-season. “We make this game progressively harder by not allowing the dog watch the victim run away,” explains Dave Leffler, Breckenridge's ski patroller and head of the avy dog program, who has owned, trained and raised many of them. Eventually, the trainers “dig an open hole in the snow to duck out of sight and gradually turn the hole into a cave where the dog has to dig to get the victim,” explains Leffler.
By the time he is three, Lume, like Huckleberry, will be a fully trained avy pup and will join seven other avy dogs on Breckenridge ski patrol team. Some of the team members, both human and canine, are also certified to work with Colorado Rapid Avalanche Deployment, a coordinated response team that works with the Summit County Sheriff’s office for avalanche emergencies outside of the ski slopes’ boundaries.
There have been 19 avalanche deaths in the U.S. this season, according to avalanche.org, which tracks slides; eight in Colorado. During the entirety of last season there were 17. Avalanche season runs from November through June, but avalanches can occur year-round.
High tech and high stakes
Complementing avy dogs’ ability to smell people buried in a slide, avalanche detection, rescue and recovery is becoming increasingly high tech. There are transceivers, signal locators, ground scanners and drones, which are considered “games changers” by many in avalanche rescue and recovery
For a person buried in an avalanche, the chance of survival plummets after 20 minutes, so every moment counts.
A drone can provide thermal imaging of objects caught in a slide; what looks like a rock from far away might be a human with a heat signature. Transceivers, also known as beacons, send a signal from an avalanche victim to a companion. Signal locators, like RECCO reflectors which are often sewn directly into gear, can echo back a radar signal sent by a detector; most ski resorts have RECCO detector units.
Research suggests that Ground Penetrating Radar (GPR), an electromagnetic tool used by geophysicists to pull images from inside the ground, could be used to locate an avalanche victim. A new study from the Department of Energy’s Sandia National Laboratories suggests that a computer program developed to pinpoint the source of a chemical or biological terrorist attack could also be used to find someone submerged in an avalanche. The search algorithm allows for small robots (described as cockroach-sized) to “swarm” a search area. Researchers say that this distributed optimization algorithm can help find avalanche victims four times faster than current search mechanisms. For a person buried in an avalanche, the chance of survival plummets after 20 minutes, so every moment counts.
An avy dog in training is picking up scent
Sarah McLear
While rescue gear has been evolving, predicting when a slab will fall remains an emerging science — kind of where weather forecasting science was in the 1980s. Avalanche forecasting still relies on documenting avalanches by going out and looking,” says Ethan Greene, director of the Colorado Avalanche Information Center (CAIC). “So if there's a big snowstorm, and as you might remember, most avalanches happened during snowstorms, we could have 10,000 avalanches that release and we document 50,” says Greene. “Avalanche forecasting is essentially pattern recognition,” he adds--and understanding the layering structure of snow.
However, determining where the hazards lie can be tricky. While a dense layer of snow over a softer, weaker layer may be a recipe for an avalanche, there’s so much variability in snowpack that no one formula can predict the trigger. Further, observing and measuring snow at a single point may not be representative of all nearby slopes. Finally, there’s not enough historical data to help avalanche scientists create better prediction models.
That, however, may be changing.
Last year, an international group of researchers created computer simulations of snow cover using 16 years of meteorological data to forecast avalanche hazards, publishing their research in Cold Regions Science and Technology. They believe their models, which categorize different kinds of avalanches, can support forecasting and determine whether the avalanche is natural (caused by temperature changes, wind, additional snowfall) or artificial (triggered by a human or animal).
With smell receptors ranging from 800 million for an average dog, to 4 billion for scent hounds, canines remain key to finding people caught in slides.
With data from two sites in British Columbia and one in Switzerland, researchers built computer simulations of five different avalanche types. “In terms of real time avalanche forecasting, this has potential to fill in a lot of data gaps, where we don't have field observations of what the snow looks like,” says Simon Horton, a postdoctoral fellow with the Simon Fraser University Centre for Natural Hazards Research and a forecaster with Avalanche Canada, who participated in the study. While complex models that simulate snowpack layers have been around for a few decades, they weren’t easy to apply until recently. “It's been difficult to find out how to apply that to actual decision-making and improving safety,” says Horton. If you can derive avalanche problem types from simulated snowpack properties, he says, you’ll learn “a lot about how you want to manage that risk.”
The five categories include “new snow,” which is unstable and slides down the slope, “wet snow,” when rain or heat makes it liquidly, as well as “wind-drifted snow,” “persistent weak layers” and “old snow.” “That's when there's some type of deeply buried weak layer in the snow that releases without any real change in the weather,” Horton explains. “These ones tend to cause the most accidents.” One step by a person on that structurally weak layer of snow will cause a slide. Horton is hopeful that computer simulations of avalanche types can be used by scientists in different snow climates to help predict hazard levels.
Greene is doubtful. “If you have six slopes that are lined up next to each other, and you're going to try to predict which one avalanches and the exact dimensions and what time, that's going to be really hard to do. And I think it's going to be a long time before we're able to do that,” says Greene.
What both researchers do agree on, though, is that what avalanche prediction really needs is better imagery through satellite detection. “Just being able to count the number of avalanches that are out there will have a huge impact on what we do,” Greene says. “[Satellites] will change what we do, dramatically.” In a 2022 paper, scientists at the University of Aberdeen in England used satellites to study two deadly Himalayan avalanches. The imaging helped them determine that sediment from a 2016 ice avalanche plus subsequent snow avalanches contributed to the 2021 avalanche that caused a flash flood, killing over 200 people. The researchers say that understanding the avalanches characteristics through satellite imagery can inform them how one such event increases the magnitude of another in the same area.
Avy dogs trainers hide in dug-out holes in the snow, teaching the dogs to find buried victims
Sarah McLear
Lifesaving combo: human tech and Mother Nature’s gear
Even as avalanche forecasting evolves, dogs with their built-in rescue mechanisms will remain invaluable. With smell receptors ranging from 800 million for an average dog, to 4 billion for scent hounds, canines remain key to finding people caught in slides. (Humans in comparison, have a meager 12 million.) A new study published in the Journal of Neuroscience revealed that in dogs smell and vision are connected in the brain, which has not been found in other animals. “They can detect the smell of their owner's fingerprints on a glass slide six weeks after they touched it,” says Nicholas Dodman, professor emeritus at Cummings School of Veterinary Medicine at Tufts University. “And they can track from a boat where a box filled with meat was buried in the water, 100 feet below,” says Dodman, who is also co-founder and president of the Center for Canine Behavior Studies.
Another recent study from Queens College in Belfast, United Kingdom, further confirms that dogs can smell when humans are stressed. They can also detect the smell of a person’s breath and the smell of the skin cells of a deceased person.
The emerging avalanche-predicting human-made tech and the incredible nature-made tech of dogs’ olfactory talents is the lifesaving “equipment” that Leffler believes in. Even when human-made technology develops further, it will be most efficient when used together with the millions of dogs’ smell receptors, Leffler believes. “It is a combination of technology and the avalanche dog that will always be effective in finding an avalanche victim.”
Living with someone changes your microbiome, new research shows
Some roommate frustration can be expected, whether it’s a sink piled high with crusty dishes or crumbs where a clean tabletop should be. Now, research suggests a less familiar issue: person-to-person transmission of shared bacterial strains in our gut and oral microbiomes. For the first time, the lab of Nicola Segata, a professor of genetics and computational biology at the University of Trento, located in Italy, has shown that bacteria of the microbiome are transmitted between many individuals, not just infants and their mothers, in ways that can’t be explained by their shared diet or geography.
It’s a finding with wide-ranging implications, yet frustratingly few predictable outcomes. Our microbiomes are an ever-growing and changing collection of helpful and harmful bacteria that we begin to accumulate the moment we’re born, but experts are still struggling to unravel why and how bacteria from one person’s gut or mouth become established in another person’s microbiome, as opposed to simply passing through.
“If we are looking at the overall species composition of the microbiome, then there is an effect of age of course, and many other factors,” Segata says. “But if we are looking at where our strains are coming from, 99 percent of them are only present in other people’s guts. They need to come from other guts.”
If we could better understand this process, we might be able to control and use it; perhaps hospital patients could avoid infections from other patients when their microbiome is depleted by antibiotics and their immune system is weakened, for example. But scientists are just beginning to link human microbiomes with various ailments. Growing evidence shows that our microbiomes steer our long-term health, impacting conditions like obesity, irritable bowel syndrome, type 2 diabetes, and cancer.
Previous work from Segata’s lab and others illuminated the ways bacteria are passed from mothers to infants during the first few months of life during vaginal birth, breastfeeding and other close contact. And scientists have long known that people in close proximity tend to share bacteria. But the factors related to that overlap, such as genetics and diet, were unclear, especially outside the mother-baby dyad.
“If we look at strain sharing between a mother and an infant at five years of age, for example, we cannot really tell which was due to transmission at birth and which is due to continued transmission because of contact,” Segata says. Experts hypothesized that they could be caused by bacterial similarities in the environment itself, genetics, or bacteria from shared foods that colonized the guts of people in close contact.
Strain sharing was highest in mother-child pairs, with 96 percent of them sharing strains, and only slightly lower in members of shared households, at 95 percent.
In Italy, researchers led by Mireia Valles-Colomer, including Segata, hoped to unravel this mystery. They compared data from 9,715 stool and saliva samples in 31 genomic datasets with existing metadata. Scientists zoomed in on variations in each bacterial strain down to the individual level. They examined not only mother-child pairs, but people living in the same household, adult twins, and people living in the same village in a level of detail that wasn’t possible before, due to its high cost and difficulties in retrieving data about interactions between individuals, Segata explained.
“This paper is, with high granularity, quantifying the percent sharing that you expect between different types of social interactions, controlling for things like genetics and diet,” Gibbons says. Strain sharing was highest in mother-child pairs, with 96 percent of them sharing strains, and only slightly lower in members of shared households, at 95 percent. And at least half of the mother-infant pairs shared 30 percent of their strains; the median was 12 percent among people in shared households. Yet, there was no sharing among eight percent of adult twins who lived separately, and 16 percent of people within villages who resided in different households. The results were published in Nature.
It’s not a regional phenomenon. Although the types of bacterial strains varied depending on whether people lived in western and eastern nations — datasets were drawn from 20 countries on five continents — the patterns of sharing were much the same. To establish these links, scientists focused on individual variations in shared bacterial strains, differences that create unique bacterial “fingerprints” in each person, while controlling for variables like diet, demonstrating that the bacteria had been transmitted between people and were not the result of environmental similarities.
The impact of this bacterial sharing isn’t clear, but shouldn’t be viewed with trepidation, according to Sean Gibbons, a microbiome scientist at the nonprofit Institute for Systems Biology.
“The vast majority of these bugs are actually either benign or beneficial to our health, and the fact that we're swapping and sharing them and that we can take someone else's strain and supplement or better diversify our own little garden is not necessarily a bad thing,” he says.
"There are hundreds of billions of dollars of investment capital moving into these microbiome therapeutic companies; bugs as drugs, so to speak,” says Sean Gibbons, a microbiome scientist at the Institute for Systems Biology.
Everyday habits like exercising and eating vegetables promote a healthy, balanced gut microbiome, which is linked to better metabolic and immune function, and fewer illnesses. While many people’s microbiomes contain bacteria like C. diff or E. coli, these bacteria don’t cause diseases in most cases because they’re present in low levels. But a microbiome that’s been wiped out by, say, antibiotics, may no longer keep these bacteria in check, allowing them to proliferate and make us sick.
“A big challenge in the microbiome field is being able to rationally predict whether, if you're exposed to a particular bug, it will stick in the context of your specific microbiome,” Gibbons says.
Gibbons predicts that explorations of microbe-based therapeutics will be “exploding” in the coming decades. “There are hundreds of billions of dollars of investment capital moving into these microbiome therapeutic companies; bugs as drugs, so to speak,” he says. Rather than taking a mass-marketed probiotic, a precise understanding of an individual’s microbiome could help target the introduction of just the right bacteria at just the right time to prevent or treat a particular illness.
Because the current study did not differentiate between different types of contact or relationships among household members sharing bacterial strains or determine the direction of transmission, Segata says his current project is examining children in daycare settings and tracking their microbiomes over time to understand the role genetics and everyday interactions play in the level of transmission that occurs.
This relatively newfound ability to trace bacterial variants to minute levels has unlocked the chance for scientists to untangle when and how bacteria leap from one microbiome to another. As researchers come to better understand the factors that permit a strain to establish itself within a microbiome, they could uncover new strategies to control these microbes, harnessing the makeup of each microbiome to help people to resist life-altering medical conditions.