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  • The First Person to Receive a Pig Kidney Transplant Has Died

    The First Person to Receive a Pig Kidney Transplant Has Died

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    Richard “Rick” Slayman, the first person to receive a kidney from a genetically modified pig, has died almost two months after the transplant. He was 62.

    The historic procedure was carried out on March 16 at Massachusetts General Hospital. In a statement released on May 11, the hospital said it had “no indication” that Slayman’s death was the result of the pig kidney transplant.

    Slayman had previously received a kidney from a human donor in 2018, but it began to fail in 2023. He was a candidate for another human kidney transplant, but because of a shortage of available organs, he would have likely waited years to receive one. Kidneys are the most needed of all donor organs, with nearly 90,000 people in the US alone waiting to receive one. For decades, researchers have been interested in the idea of using animal organs to address this problem.

    Slayman’s doctors suggested a pig kidney transplant after months of dialysis complications. In dialysis, a machine connects to a major blood vessel to remove waste and excess fluid when the kidneys have stopped functioning. But Slayman’s blood vessels kept clotting and failing, landing him in the hospital regularly and significantly impacting his quality of life.

    Pig kidney transplants had been tested only in recently deceased individuals up until then. Slayman was the first living person to receive one. “I saw it not only as a way to help me, but a way to provide hope for the thousands of people who need a transplant to survive,” Slayman said in a hospital statement in March.

    In a press conference on March 21, Slayman’s surgical team reported that the kidney had started working normally shortly after it was in place. About a week after the transplant, however, doctors noticed initial signs of rejection. They were able to treat Slayman quickly with drugs to counteract this, and afterward he was doing so well that he was released from the hospital. No further details are known about Slayman’s condition after his discharge. When contacted by WIRED, a spokesperson for Massachusetts General said the hospital could not provide any other information at this time.

    A second living person, 54-year-old Lisa Pisano, received a genetically engineered pig kidney last month. That surgery, which also included transplanting the pig’s thymus gland, was carried out at NYU Langone Health.

    Transplanting organs from one species to another is known as xenotransplantation. The primary hurdle with using pig organs in people is the human immune system, which recognizes animal tissue as foreign and rejects it.

    To address this incompatibility, scientists have turned to genetic engineering. In Slayman’s case, surgeons used a pig with 69 genetic edits, created by eGenesis, a biotech company in Cambridge, Massachusetts. The edits removed harmful pig genes and added certain human ones.

    In the New York case, Pisano received a kidney from a pig with a single genetic edit, produced by Revivicor in Virginia. Her doctors are instead relying on the implanting of the pig’s thymus, an organ that’s part of the immune system, to help prevent rejection. Patients that get pig transplants will also need to take immunosuppressant drugs for the rest of their lives to reduce the risk of rejection.

    In 2022 and 2023, surgeons at the University of Maryland tried transplanting hearts from gene-edited pigs into two patients who were not eligible for human ones. In those cases, pigs with 10 genetic edits were used. Both individuals died around two months after their transplants.

    In a statement released by Mass General, Slayman’s family said they feel comforted by the optimism he provided other patients who are waiting for a transplant. “His legacy will be one that inspires patients, researchers, and health care professionals everywhere,” they said.

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  • Pigs seem less stressed if their barn is scented with lavender

    Pigs seem less stressed if their barn is scented with lavender

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    Conditions in farms can be stressful for pigs

    KSCHiLI/Shutterstock

    Farmed pigs appear to find life less stressful when they can sniff the scent of lavender a few times a day.

    When it is sprayed into the pigs’ pens, lavender oil leads to less aggression and self-directed tail biting, as well as more time spent lying down, a study has found. This suggests the plant extract might help young pigs cope with the constraints of commercial farming better, says Alberto Elmi at the University of Pisa in Italy.

    …

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  • In Defense of Parasitic Worms

    In Defense of Parasitic Worms

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    CAPTION: Chelsea Wood kneels to search for shore crabs at a beach in Tacoma, Washington. She will later dissect the crabs to search for parasites.
    CREDIT: Jesse Nichols/Grist

    The parasites were a sign that the local shorebirds were doing great, Wood explained.

    As scientists have learned more about parasites, some have argued that many ecosystems might actually need them in order to thrive. “Parasites are a bellwether,” she said. “So if the parasites are there, you know that the rest of the hosts are there as well. And in that way they signal about the health of the ecosystem.”

    To understand this counterintuitive idea, it’s helpful to look at another class of animals that people used to hate: predators.

    For years, many communities used to treat predators as a kind of vermin. Hunters were encouraged to kill wolves, bears, coyotes, and cougars in order to protect themselves and their property. But eventually, people started noticing some major consequences. And nowhere was this phenomenon more apparent than in Yellowstone National Park.

    In the 1920s, gray wolves were systematically eradicated from Yellowstone. But once the wolf population had been eliminated from the park, the number of elk began to grow unchecked. Eventually, herds were overgrazing near streams and rivers, driving away animals including native beavers. Without beavers to build dams, ponds disappeared and the water table dropped. Before long, the entire landscape had changed.

    In the 1990s, Yellowstone changed its policy and reintroduced gray wolves into the park. “When those wolves came back in, it was like a wave of green rolled over Yellowstone,” Wood said. This story became one of the defining parables in ecology: Predators weren’t just killers. They were actually holding entire ecosystems together.

    “I think there’s a lot of parallels between predator ecology and parasite ecology,” Wood said.

    As with the gray wolves in Yellowstone, scientists are just starting to recognize the profound ways that ecosystems are shaped by parasites.

    Take, for example, the relationship between nematomorphs, a type of parasitic worm, and creek water quality. The worms are born in the water, but spend their lives on land inside of bugs, like crickets or spiders.

    Courtesy of Grist

    CAPTION: A nematomorph worm swims in a beaker in Chelsea Wood’s office in Seattle.

    At the end of their lives, nematomorphs need to move back to the water to mate. Instead of making the dangerous journey themselves, they trick their infected hosts into giving them a ride by inducing a “water drive,” an impulse on the part of its insect host to immerse itself in water. The insect will move to the edge of the water, consider it for a little while and then jump in—to its own death, but to this parasite’s benefit.

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  • Monkeys can learn to tap to the beat of the Backstreet Boys

    Monkeys can learn to tap to the beat of the Backstreet Boys

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    With a bit of training, macaques can make rhythmic movements in time with music, an ability only shown before by a handful of animals

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  • Longest-living cat breeds revealed by life expectancy study

    Longest-living cat breeds revealed by life expectancy study

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    Birman cats are among the most long-lived

    Nils Jacobi / Alamy Stock Photo

    The longest-lived breeds of cats, including Birmans and Burmese, live more than twice as long as the shortest-lived breed, according to a study of thousands of pet cats in the UK.

    “In terms of life expectancy, there has been very little research done on cats,” says Dan O’Neill at the Royal Veterinary College in the UK. “They’re kind of invisible to science, especially compared to dogs.”

    To learn more about cat longevity, O’Neill and his colleagues analysed data on 7936 cats that died between 2019 and 2021, taken from vets in the UK.

    Overall, cats had a life expectancy of just over 11.7 years. Female cats outlived their male counterparts, with an expected lifespan of 12.5 years compared with 11.2 years.

    Crossbred cats tended to live longer than purebreds, with the two groups having expected lifespans of 11.9 and 10.4 years respectively.

    Twelve breeds, including crossbreeds, had 15 or more deaths in the data – enough to estimate their life expectancy. Topping the longevity list are Birman and Burmese cats, both with life expectancies of 14.4 years. At the bottom are Bengal cats and sphynxes, with life expectancies of 8.5 and 6.7 years respectively.

    Unlike with dogs, how long cats live doesn’t appear to correlate with traits such as body size.

    “Cats are boring – the variance between cats is usually just the length or colour of their hair,” says O’Neill. “We’re not talking like in dogs, where some breeds have twisted spines or no muzzles.”

    The team also created what are known as life tables, which predict the average remaining lifespan of cats at different ages and can be used to help cat owners decide how to treat their ill pets.

    “If your cat is 11 or 12 years old and is only expected to live another year, then it’s probably not worth doing surgery, for example,” says O’Neill.

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  • Sperm whale clicks could be the closest thing to a human language yet

    Sperm whale clicks could be the closest thing to a human language yet

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    Sperm whales seem to communicate with sequences of clicks

    Amanda Cotton

    Sperm whale calls are far more complex than we thought – and could be an animal communication system that is the closest thing to human language yet discovered.

    The claim is based on an analysis of thousands of exchanges made by east Caribbean sperm whales (Physeter macrocephalus), which were recorded over several years.

    “It’s really extraordinary to see the possibility of another species on this planet having the capacity for communication,” says Daniela Rus at the Massachusetts Institute of Technology. “We used to believe that we are the only ones.”

    Sperm whales are long-lived animals with complex social lives, with females and their young living in small groups. They hunt their prey – mainly squid – using echolocation that involves streams of regular clicks. It was known that the whales often vocalise at each other with short bursts of irregular click patterns lasting a few seconds, but their significance was unclear.

    “They dive together, they eat together, they hunt together,” says Rus. “There is so much collaboration and we hear their vocalisations while they do all these activities, so the question is, what does all this stuff mean?”

    To investigate, Rus and her team analysed nearly 9000 sperm whale calls that had been recorded using devices stuck to the animals with suction cups, as part of a monitoring project conducted between 2014 and 2018.

    Previously, it was thought that this group of whales used 21 different click patterns, known as codas. In the latest analysis, the team found that there are really 18 different basic codas, but they can be changed to give several further levels of complexity.

    For instance, sometimes a known coda would have an extra click tagged on either at the start or the end – this often seemed to indicate that it was the listening whale’s turn to speak.

    Another discovery is that sometimes known codas are stretched out by slowing them down while maintaining their rhythmic pattern.

    Based on these findings, the researchers estimate that there are several hundred possible click patterns, although only 156 were seen in this dataset. They have drawn up a sperm whale “phonetic alphabet” to help them classify future recordings.

    The whales also seem to be adding complexity by combining different codas in sequences, in the same way that human language involves adding together different letters to make words.

    “Once you have this combinatorial basis, it allows you to take a finite set of symbols [and] compose them to create an infinite number of symbols by following a set of rules,” says Pratyusha Sharma, also at MIT. “Now that we have this alphabet, the next thing we’re trying to do is see how they sequence together.”

    Paul White at the University of Southampton, UK, who wasn’t involved in the work, says the fact that sperm whales use these sounds for echolocation while hunting suggests they can accurately perceive small changes in the intervals between clicks. “There’s logic to assuming those intervals could convey information.”

    “It’s always been a mystery how sperm whales, which have quite complex social structures, communicate with each other when their signals are boring sets of pulses,” he says. “This idea that it’s the fine structure within the codas that’s conveying the information is an interesting concept.”

    If it is shown that combinations of clicks do convey a wide range of meanings, the sperm whales’ communication abilities would be unique among non-human animals.

    Some other species, including various primates, can signal to each other with a small set of calls or movements. For instance, some monkeys use different alarm calls to warn each other about various predators, such as leopards, snakes and eagles, which would require different escape strategies.

    But these communication systems are too limited to be classed as language, which is usually defined as unfettered expression of thoughts into signals.

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  • Zebras bob their heads at each other to signal cooperation

    Zebras bob their heads at each other to signal cooperation

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    Zebras seem to communicate by bobbing their heads

    Martin Lindsay / Alamy

    Zebras bob their heads to attract attention and initiate social interactions such as grooming or moving together. This may be one of the few documented examples of signals that animals use to coordinate their behaviour.

    The capacity for multiple animals to focus on shared goals or objects in their environment, known as joint attention, is key to cooperation in humans, but it has rarely been investigated in wild animals.

    Severine…

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  • No One Knows How Far Bird Flu Has Spread

    No One Knows How Far Bird Flu Has Spread

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    In late March, the US Department of Agriculture (USDA) announced it had detected cases of bird flu in dairy cattle. Initially discovered in dairy farms in Texas, Kansas, and New Mexico, there are now 36 confirmed outbreaks in dairy herds in nine states.

    Although the H5N1 virus circulates widely in wild birds, it is now circulating among dairy cattle in the US. The USDA has confirmed transmission between cows in the same herd, from cows to birds, and between different dairy cattle herds.

    But the reported outbreaks are likely to be a major underestimation of the true spread of the virus, says James Wood, head of veterinary medicine at the University of Cambridge. “It’s likely there is going to be a fair amount of underreporting and underdiagnosis,” he says.

    Tests by the Food and Drug Administration (FDA) of retail milk samples might give some indication of how widespread the virus is. The agency found viral fragments in one in five samples of commercial milk, although this virus had been deactivated by pasteurization so was not infectious.

    So far there is only one confirmed human infection in the outbreak: someone in Texas who had close contact with dairy cattle. Their only reported symptom was conjunctivitis, and the individual was told to isolate themselves and take an antiviral drug for flu. But anecdotal reports of illness on dairy farms hints that infections among humans may be more widespread than official data suggests. Although human infections have tended to be rare, the virus is dangerous—just over half of the human cases recorded by the World Health Organization over the past two decades have been fatal.

    Dairy workers are most at risk of possible infection in the current outbreak, but understanding the extent of any infections is extremely tricky, says James Lawler, professor of infectious diseases at University of Nebraska Medical Center. More than half of workers in the US dairy industry are immigrants, and many of them are undocumented.

    These undocumented workers are unlikely to want to put themselves at risk by coming for testing, Lawler says. “There’s an inherent disincentive that many of the workers, because of their status as undocumented immigrants, are not raising their hands.” The result, Lawler says, is that it’s difficult for scientists to track any possible spread of the virus through humans.

    Another issue is incentivizing owners of dairy farms to report when their animals seem sick. The USDA Animal and Plant Health Inspection Service specifically provides payments for poultry farmers who have to kill their livestock due to bird flu infections. Dairy farmers don’t get compensated for reporting infections, which incentivizes producers to keep quiet, upping the risk that outbreaks get out of hand and spread to other cattle or farm workers.

    This presents a major problem for tracking the spread of the disease. “From the perspective of a producer, how is it going to benefit them to share or even test and understand if there’s a virus circulating in their herd?” Lawler says.

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  • Red squirrels were hosts for leprosy in medieval England

    Red squirrels were hosts for leprosy in medieval England

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    Red squirrels can carry bacteria that cause leprosy

    Karin Greevy/Shutterstock

    The DNA of leprosy-causing bacteria has been found in the remains of people and a red squirrel unearthed at medieval sites in the UK. This makes red squirrels the earliest known non-human hosts of the infection and suggests it may have spread between the rodents and people at the time.

    In 2016, scientists found that red squirrels (Sciurus vulgaris) around the UK carry strains of Mycobacterium leprae, the bacterium that causes the chronic disease leprosy. Some of the strains were similar to ones that infected people in England more than 700 years ago.

    “So, we had an inkling that maybe medieval red squirrels have had it too,” says Sarah Inskip at the University of Leicester in the UK.

    To investigate further, Inskip and her colleagues examined the remains of 25 people uncovered at the site of a medieval hospital for people with leprosy in Winchester and 12 red squirrels found at a nearby site that was home to at least one fur shop between the 11th and 13th centuries.

    Most of the human bones exhibited the characteristic lesions associated with leprosy, while the squirrel bones showed signs of inflammation, another possible sign of the disease.

    By analysing the DNA in the bones, the team found genetic sequences from M. leprae in three people and one red squirrel.

    “There really was leprosy circulating among medieval squirrels,” says Inskip, making the species the earliest reported non-human carrier of leprosy.

    The DNA showed that the strain of M. leprae found in the medieval red squirrel was more closely related to those in the three medieval people than to those in modern red squirrels. This indicates that the infection probably spread back and forth between squirrels and people in England in the Middle Ages.

    “There were a lot of opportunities for transmission in medieval Winchester,” says Verena Schünemann at the University of Basel, Switzerland, who also worked on the study. In addition to the hospital and well-known fur trade in the city, historical reports from the period suggest that people in the area often kept squirrels as pets, she says.

    The findings also suggest that the leprosy strains found in modern squirrels may not necessarily have descended from the strain found in this specimen. “It may be that there has been more than one transmission event between humans and squirrels over history,” says Inskip.

    Although some small populations of red squirrels have leprosy today, it is important to stress that the transmission risk to people is basically zero, says Schünemann.

    “Leprosy has definitely been around for a long time and M. leprae likely has a far more robust ecological history than our previous modern-day observations might have suggested,” says Richard Truman, formerly at the US Public Health Service. “It is important that we understand this better.”

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  • Flies undertake epic migrations that may be vital for pollination

    Flies undertake epic migrations that may be vital for pollination

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    Pied hoverflies migrate to the UK from mainland Europe

    Will Leo Hawkes

    Many species of flies migrate for hundreds or thousands of kilometres, often in vast numbers, a review of the evidence shows. These largely overlooked migrations mean flies may play a key role in many ecosystems, in particular by carrying pollen for much longer distances than other pollinators such as bees.

    This role could be especially important as the world gets hotter, says Will Hawkes at the University of Exeter in the UK, by allowing plants to acquire genetic variants from…

    Article amended on 3 May 2024

    The picture caption was amended to correctly identify the species depicted.

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