Genetically modified mosquitoes can put a dent in dengue cases. The first evidence of the health effects of releasing the insects into the real world comes from a year’s worth of disease data from Brazil, says biotech company Oxitec, the mosquitoes’ engineer.
Over much of the city of Piracicaba, where conventional methods of mosquito control were used, cases of the debilitating virus dropped 52 percent from mid-2015 to mid-2016. But in neighborhoods where Oxitec released GM Aedes aegypti mosquitoes as an extra control, the results were even better. Dengue cases there dropped 91 percent, from 133 to 12, according to a press statement from Oxitec, based in Abingdon, England. SUBSCRIBE Oxitec’s genetically modified line of Ae. aegypti mosquitoes attack a wild population by romantic deception. The GM males sire offspring with built-in self-destruct DNA that kills the new generation off in the wild before they begin to bite. This is the modern biotech twist on a decades-old strategy for controlling insects by releasing sterile males in such numbers that many females waste their reproductive effort, and a population eventually breeds itself out of existence.
In tests around the world before this, Oxitec has published or released evidence that mosquito numbers go down when the GM decoys swarm through a neighborhood. But this is the first claim that reducing those mosquitoes indeed means less disease. That information — though not the result of a full epidemiological study — could address a gap in the debate in the Florida Keys over a proposed test release there. Opponents of introducing GM organisms, even ones pretty reliably programmed to die, have objected that there has been no evidence the measure brings any health benefit.
Brazil, where dengue and now Zika have wreaked havoc, has been much more open to the use of GM mosquitoes. In this case, Oxitec looked at the numbers of dengue cases reported mid-year to mid-year from Piracicaba’s epidemiologic surveillance program. The GM mosquito test focused on an area, called CECAP/Eldorado, of about 5,000 residents where the dengue rates were higher than in the rest of the city in 2014‒2015 — 2.66 percent incidence rate versus 0.902 percent. After a year of control measures including releasing the GM mosquitoes, the 2015‒2016 numbers show the test area now fares better than the rest of the city. Its dengue incident rate dropped to 0.24 percent compared with the municipality incidence rate of 0.437 percent.
Data on mosquito populations and diseases are rare and important, says Grayson Brown, who directs the Public Health Entomology lab at the University of Kentucky in Lexington. He wonders how far down the GM mosquitoes drove the wild population before dengue rates started dropping. (Oxitec reports that mosquito numbers dropped 82 percent, but, Brown asks, 82 percent of what?) Such a useful number turns out to be virtually unknown for most mosquito-borne diseases and their countermeasures, except for malaria, he says. Plenty of programs monitor disease outbreaks as they treat mosquitoes, but ethically and politically, “you can’t just leave a section of the city untreated.” Adding the extra measure of the GM treatments offers a way to fill that data gap.
Alcoholism may stem from using genes incorrectly, a study of hard-drinking rats suggests.
Rats bred either to drink heavily or to shun alcohol have revealed 930 genes linked to a preference for drinking alcohol, researchers in Indiana report August 4 in PLOS Genetics.
Human genetic studies have not found most of the genetic variants that put people at risk for alcoholism, says Michael Miles, a neurogenomicist at Virginia Commonwealth University in Richmond. The new study takes a “significant and somewhat novel approach” to find the genetic differences that separate those who will become addicted to alcohol from those who drink in moderation. It took decades to craft the experiment, says study coauthor William Muir, a population geneticist at Purdue University in West Lafayette, Ind. Starting in the 1980s, rats bred at Indiana University School of Medicine in Indianapolis were given a choice to drink pure water or water mixed with 10 percent ethanol, about the same amount of alcohol as in a weak wine. For more than 40 generations, researchers selected rats from each generation that voluntarily drank the most alcohol and bred them to create a line of rats that consume the rat equivalent of 25 cans of beer a day. Simultaneously, the researchers also selected rats that drank the least alcohol and bred them to make a line of low-drinking rats. A concurrent breeding program produced another line of high-drinking and teetotaling rats.
For the new study, Muir and colleagues collected DNA from 10 rats from each of the high- and low-drinking lines. Comparing complete sets of genetic instructions from all the rats identified 930 genes that differ between the two lines.
Such a large number of genes, “shows how complex the genetic underpinnings of the drive to consume alcohol might be,” says Miles.
Often, human genetic studies known as genome-wide association studies, or GWAS, can’t determine which of many genes in a particular region of DNA is involved in a disease or addiction. But the Indiana researchers’ DNA data allowed them to pinpoint the exact genetic tweaks implicated in the rats’ drinking. “With GWAS, they’re just trying to get down to the gene — we’ve got it down to the parts of the genes,” Muir says.
That precision “is clearly an advance,” says John Crabbe, a neuroscientist at the Portland VA Medical Center in Oregon. “No one has gone into this much detail before in any alcohol-related trait.” Most of the time, the genetic variant associated with drinking behavior wasn’t located within the part of the gene containing blueprints for a protein, the researchers discovered. Only four genes contained variants in their protein-producing parts. The majority of the differences were in surrounding DNA that regulates gene activity. Those changes could alter how much protein is produced from the genes, says study coauthor Feng Zhou, a neurobiologist at Indiana University School of Medicine. In turn, altering amounts of proteins could shift biochemical reactions important for determining behavior.
Until recently, scientists thought alcoholism and other problems stemmed from inheriting altered forms of genes that would produce faulty proteins. “Well, that game’s over,” says Crabbe. Now researchers realize that regulating gene activity is often just as important as changing the genes themselves.
The researchers don’t yet know whether the genes identified in the rats are the same ones that lead to drinking problems in people.
Understanding sea anemones’ exceptional healing abilities may help scientists figure out how to restore hearing.
Proteins that the marine invertebrates use to repair damaged cells can also repair mice’s sound-sensing cells, a new study shows. The findings provide insights into the mechanics of hearing and could lead to future treatments for traumatic hearing loss, researchers report in the Aug. 1 Journal of Experimental Biology.
“This is a preliminary step, but it’s a very useful step in looking at restoring the structure and function of these damaged cells,” says Lavinia Sheets, a hearing researcher at Harvard Medical School who was not involved in the study. Tentacles of starlet sea anemones (Nematostella vectensis) are covered in tiny hairlike cells that sense vibrations in the water from prey swimming nearby. The cells are similar to sound-sensing cells found in the ears of humans and other mammals. When loud noises damage or kill these hair cells, the result can range from temporary to permanent hearing loss.
Anemones’ repair proteins restore their damaged hairlike cells, but landlubbing creatures aren’t as lucky. Glen Watson, a biologist at the University of Louisiana at Lafayette, wondered if anemones’ proteins — which have previously been shown to mend similar cells in blind cave fish — might also work in mammals.
Watson and colleagues mimicked traumatic hearing loss in mice hair cells by depriving them of calcium ions, which are crucial for maintaining cell structure and transmitting sounds. Within a few hours, the normally stiff, hairlike structures that detect sound “looked like spaghetti,” he says. Researchers bathed the damaged hair cells in a cocktail of anemone repair proteins. After an hour, the cells showed remarkable improvement compared with untreated cells. Proteins rebuilt molecular tethers that bundle hair cells and act as gatekeepers for calcium ions. As a result, the cells absorbed more fluorescent dye — an indication of how well calcium flows into the cells.
What’s more, researchers identified a bevy of mice proteins that are analogs of anemones’ repair proteins. But mammalian versions work less effectively than anemone proteins, if at all. More research could point the way to one day harnessing human repair proteins, Sheets says.
Moving forward, Watson plans to investigate the ability of the anemones’ proteins to repair damaged cells in the ears of living mice. “If we could get to those hair cells before they commit to die and treat them, there’s a possibility we could reduce hearing loss,” he says.
A radio signal detected last year has sparked speculation that an advanced alien civilization is broadcasting from a relatively nearby planet. But recent scans have turned up nothing, suggesting the blip was a false alarm and nothing more than earthly interference.
In May 2015, astronomers detected a blast of radio waves coming from the direction of HD 164595, a sunlike star about 94 light-years away in the constellation Hercules. The signal, reported online August 27 on the blog Centauri Dreams, lasted just a few seconds and reached a peak power of about 750 millijansky — fairly strong by radio astronomy standards (1 jansky equals 10-26 watts per square meter per hertz). The researchers aren’t claiming that they found E.T., but they are asking other astronomers to monitor the star — home to a planet at least 16 times as massive as Earth — in case the signal repeats. So far, all is quiet.
Scientists with the SETI Institute, whose mission is to seek out signs of extraterrestrial intelligence, turned the Green Bank Telescope in West Virginia toward HD 164595 on August 28 to scan for signals. “There was nothing there,” says Dan Werthimer, a SETI astronomer at the University of California, Berkeley. The original claim, however, “is consistent with someone pushing the button on a CB radio for a couple of seconds.”
Radio telescopes have to contend with interference from the civilization on this planet before picking out transmissions from our galactic neighbors. Earth-based satellites, power lines and cellphones all emit radio waves that can overwhelm cosmic signals. One type of radio chirp whose origin had eluded astronomers for years recently turned out to be coming from microwave ovens, a fact discovered when researchers at the Parkes observatory in Australia who were tracking the signal prematurely opened an oven door without waiting for the ding signal (SN: 5/16/15, p. 5).
“We see strong signals like this all the time,” says Werthimer. With enough information, such as frequency and location, researchers can usually figure out the cause of an incoming signal. But this latest finding, recorded at the RATAN-600 radio observatory near the Caucasus Mountains in Russia, is missing a lot of details that could help astronomers assess its origin. Without precise frequency measurements or statistics on how often the observatory detects comparable events, says Werthimer, it’s hard to tell how unusual this signal is.
The signal was detected around a frequency of 11 gigahertz. That suggests interference from telecommunication devices, says Italian astronomer Claudio Maccone, who was part of the discovery team. “This is precisely why many countries have to watch the star with different technologies,” he says. “By comparing results, we may be able to find the answer.” The long delay in sharing the results, he says, comes from a reluctance among his Russian colleagues to interact with Western researchers. “They are a closed community,” he says. “It’s an unfortunate circumstance.” The team will present the findings September 27 at a meeting of the International Academy of Astronautics in Guadalajara, Mexico. If the signal didn’t originate on Earth, there are also plenty of natural cosmic sources. Jean Schneider, an astrophysicist at the Paris Observatory in Meudon, France, contends that a gravitational microlens might be responsible. Gravity from an object, such as a star or planet, can temporarily amplify light — including radio waves — received on Earth from other more distant bodies that the interloper passes in front of. Testing that idea would require meticulously tracking the movement of stars that lie in the direction of the radio signal, says Schneider, and seeing if anything could have lined up on the day of the detection.
The discovery is reminiscent of an infamous — and still unexplained — detection known as the “Wow!” signal, named after what astronomer Jerry Ehman wrote on a printout of the signal. Detected in 1977 at the Big Ear radio telescope in Delaware, Ohio, the Wow! signal was at least 70 times as powerful as the one at RATAN-600, lasted for about 72 seconds and appeared to originate in the constellation Sagittarius. Many ideas have been put forth about the signal’s origin, including comets in our solar system, Earth-orbiting space debris and, of course, extraterrestrials.
If aliens do reside around HD 164595, and they are trying to get our attention, they could do so with precisely aimed transmitters no more powerful than anything on Earth, Werthimer says. But if we eavesdropped on a signal that was blasting in all directions into space, then our neighbors are far more advanced than us; such a device would require tapping into the entire power output of their sun.
Anna Frebel can’t explain her fascination with the stars. It’d be like explaining why “berry purple-pink” is one of her favorite colors. “They are just a part of me,” says Frebel, an astronomer at MIT. “What’s going on with them and what they can tell us — there is something magical.”
Frebel’s fascination has led to the discovery of at least three record-breaking stars. Dating back roughly 13 billion years, the stars — all within the Milky Way galaxy — might be elders from the second generation of stars ever formed in the universe. She has also found that one of the tiny galaxies flitting around outside the Milky Way might be a fossil that has survived from not long after the Big Bang. The light from these ancient relics encodes stories about the birth of the first stars, the assembling of galaxies and the origin of elements essential to creating planets and life as we know i “Anna has a really good track record of finding these amazing things,” says Alexander Ji, one of the three graduate students Frebel mentors at MIT. “She’s always finding things that change our understanding of the universe.” As a young girl living in Germany, Frebel wanted to be an astronaut, but she passed on that dream when she learned about the centrifuge that whips trainees around to simulate launch acceleration. Not for her. She instead studied physics and astronomy, first at the University of Freiburg in Germany and then at the Australian National University in Canberra. Since then, Frebel, now 36, has earned a reputation as a “stellar archaeologist,” with the patience and perseverance to search through the universe’s most ancient debris.
Only someone with a galaxy’s worth of patience could sift through the tiny rainbows of light, the spectra, produced by thousands of stars, handpicking the specimens that might preserve clues to the conditions shortly after the first stars lit up the universe. And only a persistent person would spend more than two years pointing Australia’s 2.3-meter-wide Advanced Technology Telescope at 1,200 of the most promising candidates (“105 stars per night was my record,” she says) and eventually, with observations from other telescopes too, land on one star that was, for a while, among the oldest known.
She was first drawn to this research after hearing astronomer Norbert Christlieb, then a visiting researcher at the Australian National University, talk about his work on old stars. “It hit me: Oh my God, this project combines all my interests,” Frebel says. There were stars, chemistry, nuclear physics and the periodic table. “There are so many, for me, cool topics that come together.”
In combing through her stars, Frebel was looking for ones that contained hydrogen and helium — but little else. Most heavier elements up to iron are forged in the cores of stars, where atomic nuclei smash together. As the universe aged, its inventory of atoms such as carbon, silicon and iron steadily increased. The earliest stars, however, came on the scene when there were far fewer of these pollutants floating around. Her efforts paid off in 2005 with a star branded HE 1327-2326, reported in
Nature
asthe most pristine star known at the time
. “She found one that took us closer back to the beginning of time as we know it,” says Frebel’s Ph.D. adviser, astronomer John Norris of Australian National. “It became clear to us early on that she was quite gifted.”
Her gifts netted her the Charlene Heisler Prize in 2007, given by the Astronomical Society of Australia for outstanding Ph.D. thesis. She has since won several recognitions, including the Annie Jump Cannon Award in 2010, given to notable young female researchers by the American Astronomical Society, for her “pioneering work in advancing our understanding of the earliest epochs of the Milky Way galaxy through the study of its oldest stars.”
Carbon seeding The geriatric stars that Frebel finds are not perfectly pristine; they preserve in their atmospheres the chemical makeup of interstellar gas that had been seeded with a smidgen of heavy elements from the explosions of stars that came before. Chemical abundances in many of these stellar fossils are out of balance compared with modern stars. The fossil stars have much more carbon relative to iron, for example — carbon that had to have come from the debris of that very first crop of stars.
Frebel worked with theorists to show that excess carbon could have allowed successive generations of stars (and planets) to form, reporting the work in 2007 in Monthly Notices of the Royal Astronomical Society Letters. “I’ve always been interested in understanding the main message of the data,” she says, which leads her away from the telescope to computer simulations and theory. In this case, the message is that carbon “might have been the most important element in the universe.”
Gas needs to be cold, around –270° Celsius, just a few degrees above absolute zero, to clump and form stars. And carbon is an excellent coolant; its electrons are arranged in such a way to let it efficiently radiate energy. The first generation of stars didn’t have carbon’s help. They were probably slow to form and ended up as gargantuan fluffy orbs hundreds of times as massive as the sun. But once those stars exploded and seeded the cosmos with carbon, Frebel’s data suggest, subsequent generations of stars formed that would have looked more like the stars we see today.
Frebel likens her studies to watching her young son learn to walk and talk. “My overall interpretation is that the universe was still trialing things.”
Before she became a parent, she regularly went to one of the twin Magellan telescopes, 2,380 meters above sea level in the Chilean Atacama Desert. On long nights, while waiting for the telescope to soak up light from a star tens of thousands of light-years away, Frebel would feel the pull of the night sky. “I just lie on the ground and stare into the sky and get lost in the universe,” she says.
In recent years, Frebel has expanded her repertoire to include a horde of teeny galaxies that orbit the Milky Way and also serve as archaeological sites. “Now we can use not just one star,” she says. “We can use the entire galaxy as a fossil record.” One of these runts, called Segue 1, appears to be a remnant from the cosmic dawn and might be typical of the pieces that assembled into large galaxies like the Milky Way.
Frebel and her student Ji discovered that another dwarf galaxy, dubbed Reticulum II, contains clues about one of the mechanisms responsible for creating most of the elements heavier than iron. A long-ago smashup between two neutron stars once bombarded the gas in Reticulum II with neutrons, producing atoms, such as uranium, that can’t be formed in stellar cores. Similar run-ins in other galaxies might have helped build up the universe’s stockpile of heavy elements.
Frebel plans to continue her quest to understand the origin of atoms, stars and galaxies. Though the celestial bodies she studies are ancient, “my days never get old,” she says.
DENVER — Barnacles can tell a whale of a tale. Chemical clues inside barnacles that hitched rides on baleen whales millions of years ago could divulge ancient whale migration routes, new research suggests.
Modern baleen whales migrate thousands of kilometers annually between breeding and feeding grounds, but almost nothing is known about how these epic journeys have changed over time. Scientists can glean where an aquatic animal has lived based on its teeth. The mix of oxygen isotopes embedded inside newly formed tooth material depends on the region and local temperature, with more oxygen-18 used near the poles than near the equator. That oxygen provides a timeline of the animal’s travels. Baleen whales don’t have teeth, though. So paleobiologists Larry Taylor and Seth Finnegan, both of the University of California, Berkeley, looked at something else growing on whales: barnacles. Like teeth, barnacle shells take in oxygen as they grow. Patterns of oxygen isotopes in layers of barnacle shells collected from modern beached whales matched known whale migration routes, Taylor said September 25 at the Geological Society of America’s annual meeting. Roughly 2-million-year-old barnacle fossils have analogous oxygen isotope changes, preliminary results suggest. Converting those changes into migration maps, however, will require reconstructing how oxygen isotopes were distributed long ago, Taylor said.
A South African flower catches flies with honey, or in this case, the smell of honeybees.
Several plant species lure potential pollinators with false promises of sweet nectar, sex or even rotting flesh. But Ceropegia sandersonii attracts its primary pollinator, Desmometopa flies, with the scent of fear. The flower mimics the chemical signals, or pheromones, released by alarmed western honeybees (Apis mellifera) during a predator attack. For flies that feast on the bees’ guts, it’s the perfect bait, Stefan Dötterl, a chemical ecologist at the University of Salzburg in Austria, and colleagues report online October 6 in Current Biology. The team compared the compounds that make up the flower’s scent with pheromones released by the bees during simulated attacks. Not only did the two odors have several compounds in common, but the flies were strongly attracted to a mixture of a few of the shared compounds. That chemical cocktail has so far been observed only in the bees and C. sandersonii, the researchers say.
Before flies have a chance to wise up to the trickery, they become trapped inside the flower. The flies eventually escape about a day later, once the flower wilts, only to be duped by other flowers to finish the fertilizing task, Dötterl says.
VANCOUVER — Traces of long-lost human cousins may be hiding in modern people’s DNA, a new computer analysis suggests.
People from Melanesia, a region in the South Pacific encompassing Papua New Guinea and surrounding islands, may carry genetic evidence of a previously unknown extinct hominid species, Ryan Bohlender reported October 20 at the annual meeting of the American Society of Human Genetics. That species is probably not Neandertal or Denisovan, but a different, related hominid group, said Bohlender, a statistical geneticist at the University of Texas MD Anderson Cancer Center in Houston. “We’re missing a population or we’re misunderstanding something about the relationships,” he said. This mysterious relative was probably from a third branch of the hominid family tree that produced Neandertals and Denisovans, an extinct distant cousin of Neandertals. While many Neandertal fossils have been found in Europe and Asia, Denisovans are known only from DNA from a finger bone and a couple of teeth found in a Siberian cave (SN: 12/12/15, p. 14).
Bohlender isn’t the first to suggest that remnants of archaic human relatives may have been preserved in human DNA even though no fossil remains have been found. In 2012, another group of researchers suggested that some people in Africa carry DNA heirlooms from an extinct hominid species (SN: 9/8/12, p. 9).
Less than a decade ago, scientists discovered that human ancestors mixed with Neandertals. People outside of Africa still carry a small amount of Neandertal DNA, some of which may cause health problems (SN: 3/5/16, p. 18). Bohlender and colleagues calculate that Europeans and Chinese people carry a similar amount of Neandertal ancestry: about 2.8 percent. Europeans have no hint of Denisovan ancestry, and people in China have a tiny amount — 0.1 percent, according to Bohlender’s calculations. But 2.74 percent of the DNA in people in Papua New Guinea comes from Neandertals. And Bohlender estimates the amount of Denisovan DNA in Melanesians is about 1.11 percent, not the 3 to 6 percent estimated by other researchers.
While investigating the Denisovan discrepancy, Bohlender and colleagues came to the conclusion that a third group of hominids may have bred with the ancestors of Melanesians. “Human history is a lot more complicated than we thought it was,” Bohlender said.
Another group of researchers, led by Eske Willerslev, an evolutionary geneticist at the Natural History Museum of Denmark in Copenhagen, recently came to a similar conclusion. Willerslev’s group examined DNA from 83 aboriginal Australians and 25 people from native populations in the Papua New Guinea highlands (SN: 10/15/16, p. 6). The researchers found Denisovan-like DNA in the study volunteers, the group reported October 13 in Nature. But the DNA is genetically distinct from Denisovans and may be from another extinct hominid. “Who this group is we don’t know,” Willerslev says. They could be Homo erectus or the extinct hominids found in Indonesia known as Hobbits (SN: 4/30/16, p. 7), he speculates. But researchers don’t know how genetically diverse Denisovans were, says Mattias Jakobsson, an evolutionary geneticist at Uppsala University in Sweden. A different branch of Denisovans could be the group that mated with ancestors of Australians and Papuans.
Researchers know so little about the genetic makeup of extinct groups that it’s hard to say whether the extinct hominid DNA actually came from an undiscovered species, said statistical geneticist Elizabeth Blue of the University of Washington in Seattle. DNA has been examined from few Neandertal fossils, and Denisovan remains have been found only in that single cave in Siberia. Denisovans may have been widespread and genetically diverse. If that were the case, said Blue, the Papuan’s DNA could have come from a Denisovan population that had been separated from the Siberian Denisovans for long enough that they looked like distinct groups, much as Europeans and Asians today are genetically different from each other. But if Denisovans were not genetically diverse, the mysterious extinct ancestor could well be another species, she said.
Jakobsson says he wouldn’t be surprised if there were other groups of extinct hominids that mingled with humans. “Modern humans and archaic humans have met many times and had many children together,” he said.
Tickle a rat and it will jump for joy, gleefully squeak and beg for more. In addition to describing these delightful reactions to a tickling hand, a new study identifies nerve cells in the brain that help turn rats into squirmy puddles of giggles.
The results, published November 11 in Science, offer insight into how the brain creates glee, an understudied emotion. “People really underrate the positive things — fun, happiness, joy,” says study coauthor Shimpei Ishiyama of Humboldt University of Berlin. Scientists knew that rats seemed to enjoy a good tickle from a human, but how the brain creates that emotion was a mystery. Although no protocol existed, the tickling part of the experiment turned out to be “surprisingly easy,” Ishiyama says. He simply stuck his hand in the cages and scribbled his fingers in the rats’ fur, to their apparent delight. Tickled rats laughed by emitting an ultrasonic 50-kilohertz giggle that humans can’t hear. They also jumped for joy, an acrobatic feat called “Freudensprünge,” and chased Ishiyama’s hand around the cage. Using laughter as a measurement, Ishiyama and colleagues found that the belly, not back or tail, is a rat’s most ticklish spot.
This joyful response may be created in part by nerve cells in the somatosensory cortex. In people, this brain region responds to tickles and is usually associated with touch perception. In tickled rats, many nerve cells in the part of the somatosensory cortex that corresponds to the rodents’ trunks grew active, electrodes revealed. A light stroke activated some of these nerve cells, but not as many.
Because these nerve cells respond to touch, it’s not surprising that they grew active during a tickle, Ishiyama says. But additional experiments found active nerve cells when the rats were chasing a tickling hand without being touched — suggesting the cells are responding to something specific about a tickle, not just touch in general. What’s more, when the researchers used electrodes to stimulate the somatosensory cortex in untouched rats, the rats giggled. It turns out that ticklishness is a flighty state, and not just because some rats like to be tickled more than others. Anxious rats on a platform and in bright lights emitted fewer laughlike vocalizations than calm rats, the researchers found. Nerve cells in the somatosensory cortex were less likely to fire off signals, too, results that highlight just how mood-dependent tickling is.
The new study shows for the first time that laughter can result from stimulation of the somatosensory cortex, says neuroscientist Elise Wattendorf of the University of Fribourg in Switzerland. The brain area’s involvement in both the sensory aspects of tickling and its social context is “unexpected, and constitutes an outstanding result,” she wrote in an e-mail. Using brain scans, Wattendorf and colleagues had previously found that the somatosensory cortex was active when people laughed as they were tickled.
Many brain studies focus on troubles such as depression, Ishiyama says. But by taking the opposite approach, he hopes to reveal new insights into how the brain creates and maintains happiness. Besides, he says, “it’s also fun to study fun.”
Chinese scientists have injected a person with CRISPR/Cas9-edited cells, marking the first time cells altered with the technique have been used in humans. Researchers used the powerful gene editor to alter immune cells to fight lung cancer, Nature reports November 15.
Immune cells called CAR-T cells have already been engineered using other gene-editing technologies. A baby’s leukemia was successfully treated in 2015 with CAR-T cells engineered with gene editors known as TALENs.
Chinese researchers led by oncologist Lu You of Sichuan University in Chengdu got approval to conduct the new trial this summer. U.S. researchers have gotten clearance to begin similar clinical trials.
You’s team removed immune cells from a patient with lung cancer. They then used CRISPR/Cas9 as molecular scissors to cut and inactivate the PD-1 gene in T cells. That gene’s protein usually holds immune cells back from attacking tumors. The hope is that the edited cells will now go on the offensive and help the patient fight cancer. Researchers plan to give the patient a second dose of engineered cells, Nature reports.
The researchers’ progress with the technique could spark a space race–style biomedical competition between the United States and China, Carl June, an immunotherapist at University of Pennsylvania in Philadelphia, told Nature. “I think this is going to trigger ‘Sputnik 2.0,’” he said, hopefully improving the end product.
