"Men giving birth to children" has come true? For the first time, adult mice with two "fathers" have been bred | Science Weekly

Compiled by Zhou Shuyi and Pingsheng

New research confirms a "super-Earth" in the habitable zone

A study published in Astronomy & Astrophysics on January 28 confirmed the existence of a "super-Earth" near the habitable zone of a sun-like star. This result provides more clues for the future search for Earth-like exoplanets that may be suitable for life.

Super-Earths, also known as super-Terrestrial planets, are large, Earth-like planets that are typically composed of gas and rock and can be several times more massive than Earth. Some researchers speculate that these planets have plate tectonics similar to Earth's.

The newly discovered planet, named HD 20794 d, is six times more massive than Earth and is located about 20 light-years from Earth around a star similar to our sun. Its orbit is within the system's habitable zone, meaning it is at the right distance from the star to sustain liquid water on its surface, a key ingredient for life.

The planet was first discovered in 2022 by Dr. Michael Cretignier, a researcher at the Department of Physics at the University of Oxford. Dr. Cretignier discovered a candidate exoplanet signal while analyzing archived data recorded by the High Accuracy Radial Velocity Planet Searcher (HARPS) spectrometer at the La Sia Observatory in Chile, but due to the weak signal, its specific source could not be confirmed.

To verify this signal, an international research team analyzed high-precision data recorded over the past 20 years by HARPS and the Rocky Exoplanet and Stable Spectral Observation Echelle Spectrograph (ESPRESSO), also located in Chile. The researchers said that advanced processing methods and meticulous analysis are needed to distinguish planetary signals from background noise and instrument differences. By combining the results of the two instruments, the researchers finally confirmed the existence of this "super-Earth".

Researchers said that although the planet is located in the habitable zone of the relevant galaxy, it is too early to determine whether it can support life. Unlike most planets, HD 20794 d's orbit is not circular, but elliptical. This causes its distance from the star to vary greatly, that is, it will move from the outer edge of the habitable zone to the inner edge within one operating cycle. However, researchers believe that HD 20794 d will provide a valuable test case for future space projects to detect signs of life outside the solar system. (Xinhuanet)

FDA approves first non-opioid painkiller in decades

On January 30, local time, the U.S. Food and Drug Administration (FDA) announced the approval of Suzetrigine (trade name: Journalavx), a new non-opioid analgesic drug from Vertex Pharmaceuticals, for the treatment of moderate to severe acute pain in adults. This is the first new mechanism drug approved in the United States for the treatment of acute pain in more than two decades. Jessica Oswald, a pain medicine expert at the University of California, San Diego and a member of Vertex's Acute Pain Steering Committee, said: "Suzetrigine is an effective and well-tolerated drug, and there is currently no evidence that it is addictive."

Acute pain is often caused by surgery, accidents or injuries and can be disabling. Traditional nonsteroidal anti-inflammatory drugs have limited analgesic effects, and opioids have a serious risk of addiction. More than 80 million Americans take medications to treat moderate to severe acute pain each year, of which about 40 million take opioids, and about 85,000 patients suffer from opioid use disorder.

The efficacy of Suzetrigine has been verified in two randomized, double-blind, placebo- and active-controlled clinical trials for acute postoperative pain, one of which was for patients undergoing abdominoplasty and the other for patients undergoing bunionectomy. The experiments showed that Suzetrigine's analgesic effect was comparable to that of opioids, but with fewer side effects, and was even superior to placebo in many safety indicators.

“To me, this is very exciting,” Oswald said. Although the drug occasionally causes nausea, headaches, dizziness and constipation, it is “extremely well tolerated,” making it a viable, even preferred, alternative to opioids.

Currently, the wholesale procurement cost of Suzetrigine in the United States is US$15.50 (approximately RMB 112) per tablet (50 mg).

Over the past century, men's height and weight have increased at twice the rate of women

A study published in Biology Letters on January 22 analyzed data from dozens of countries and found that over the past century, the growth rate of men's height and weight worldwide has been twice that of women, which means that the height and weight gap between the sexes is widening.

Previous studies have shown that males and females of many species differ in size. For many species, males are larger due to competition for mates or female preferences. In some cases, females are larger due to reproductive needs. In humans, males are generally taller, heavier, and stronger than females.

In the latest study, researchers used a data set of millions of people collected by the World Health Organization since 1900, and selected about 135,000 individual cases covering 62 countries for in-depth analysis to study how height and weight change with living conditions. Living conditions are measured by the Human Development Index (HDI), which is based on life expectancy, education time and per capita income, ranging from 0 to 1. They found that for every 0.2 increase in the Human Development Index, women's height increased by an average of 1.7 cm and their weight increased by 2.7 kg; while men's height increased by an average of 4 cm and their weight increased by 6.5 kg. This shows that as living conditions improve, height and weight will increase, but the growth rate of men is more than twice that of women. In the UK, for example, in the first half of the 20th century, the average height of women increased from 159 cm to 162 cm, an increase of 1.9%, while the average height of men increased from 170 cm to 177 cm, an increase of 4%. Michael Wilson, professor of ecology, evolution and behavior at the University of Minnesota, said the accelerated growth rate of men's height and weight was "shocking."

The researchers speculate that women's sexual preferences may be fueling the trend towards taller, more muscular men. "Women may find taller men attractive because it may make them look more powerful, and being taller may also indicate that they are physically fit."

Exoskeleton helps pianists break through skill bottlenecks

For well-trained individuals such as athletes and musicians, their performance often stagnates after a lot of training, which is the so-called "ceiling effect." In a study recently published in Science Robotics, researchers designed a robotic exoskeleton to help pianists break through the "ceiling effect" by experiencing previously difficult performance experiences.

This mechanical exoskeleton can control the lifting or lowering of each finger individually by connecting independent motors at the base of each finger, at a speed of up to four times per second. The researchers recruited 118 pianists who had been playing the piano since before the age of 8 and had practiced for at least 10,000 hours. The researchers asked them to practice the same piece for two consecutive weeks until their skills reached a bottleneck.

Next, the performers received 30 minutes of "hand-on" training with the mechanical exoskeleton. The exoskeleton trained the performers' right hand fingers in different combinations of simple, complex, slow and fast modes. The results showed that the performers who received fast and complex training were able to better coordinate their right hand movements and move their fingers faster after removing the exoskeleton, and the training effect lasted until the next day. This, combined with brain scan evidence, proves that the training changed the performers' cerebral cortex, enabling them to better control finger movements. Interestingly, the training experience is "transferred" between the left and right hands - when using one hand for exoskeleton training, the untrained contralateral hand also shows improved motor skills.

“This is the first time I’ve seen anyone use an exoskeleton to push the limits of normal dexterity, to push you to learn things you can’t do naturally,” says Nathan Lepora of the University of Bristol in the UK. “It’s a bit counterintuitive because you might think that voluntary learning is the way to go, but now it seems that passive learning can be just as effective.”

If you don't sleep overnight, your brain will age the next day

For many people, the Spring Festival holiday is a rare time to stay up late. Have you ever felt this way: after staying up all night, your body is exhausted, but your brain is abnormally excited? In fact, staying up all night occasionally can indeed make people feel better - a study published in Neuron in 2023 showed that short-term acute sleep deprivation, that is, occasionally staying up late, can produce a strong antidepressant effect that lasts for several days.

In this study, researchers at Northwestern University designed an animal experiment to gently interfere with the sleep of healthy mice, causing them to experience a "sleepless day" (mice are active at night and dormant during the day, which is contrary to the circadian rhythm of humans). The behavior of these mice became more aggressive, hyperactive, and hypersexual. The researchers then used optogenetics and genetic encoding tools to detect neuronal activity in the mouse brains. The results showed that after a temporary lack of sleep, the three brain regions of the prefrontal cortex, nucleus accumbens, and hypothalamus were affected, among which the neurons releasing dopamine in the prefrontal cortex became more active, dopamine release increased, and synaptic plasticity became stronger. These changes kept the animals in high spirits for the next few days.

The researchers speculate that this mechanism may be derived from evolutionary factors. "Acute sleep deprivation will somehow 'activate' the organism. You can imagine that in some cases, if you are facing a predator or some kind of danger, you need to stay awake and delay sleep." However, the researchers also warned people not to stay up all night to relieve depression. Although this study shows that occasionally staying up all night can brighten your mood, the happiness gained by sacrificing sleep is temporary, and the harmful effects of staying up late are far-reaching and lasting.

A study published in The Journal of Neuronscience in 2023 showed that if you don’t sleep for just one night, your brain will instantly age the next day.

This conclusion comes from the data analysis of human volunteers by the German Institute of Neuroscience and Medicine. With the help of machine learning algorithms, researchers analyzed the relevant data of participants in the sleep experiment based on multiple indicators such as brain volume and cerebrospinal fluid to determine the state of the brain. The results showed that the volunteers who did not sleep for a whole night (acute total sleep deprivation) had a brain age of 1 to 2 years older the next day!

Coincidentally, another paper published in Nature Communications made a similar assessment, but used network connections between different brain regions as the basis for judging the state of the brain. The researchers also found that after just one night of sleep deprivation, the characteristics of the neural network pattern looked about 4 years older than before. These changes in the brain can also explain why lack of sleep makes us feel confused. But the good news is that these studies also show that making up for sleep the next day can reverse this abnormality. (Adapted from the official account "Academic Jingwei")

"Men giving birth to children" has come true? For the first time, adult mice with two "fathers" have been bred

In a study published in Cell Stem Cell on January 28, researchers successfully bred "bipaternal mice" (hereinafter referred to as "partner male mice"), whose genetic material all came from the father, and which could survive to adulthood healthily, by repairing the imprinted gene. The new study provides a new perspective for understanding mammalian parthenogenesis disorders and also provides clues for exploring the complex relationship between genes and environmental adaptation.

As early as the 1980s, scientists began to explore mammalian parthenogenesis. However, early experiments all ended in failure. In the early 1990s, scientists discovered a special type of gene in mammals - imprinted genes. Unlike ordinary genes, imprinted genes are only expressed from one side of the father or mother, while the other side is quietly "hidden". This mechanism makes the two sets of genomes of mammals no longer identical. The normal development of offspring is inseparable from the complete genetic information of both parents, which also limits mammals from parthenogenesis.

The new study used a microscope to remove the nucleus of the oocyte, injected mouse sperm, and cultivated haploid embryonic stem cells from male-derived mice. Previous studies have shown that multiple imprinted gene abnormalities are closely related to embryonic development problems, especially abnormal diploidization of paternal DNA, which usually leads to early embryonic death. The research team repaired these imprinted areas one by one in the male-derived haploid embryonic stem cells, and then injected the gene-edited embryonic stem cells and another sperm into the enucleated oocyte. However, the internal organs of the edited male-derived mice were severely edematous and could not survive normally.

Male-female mice with six key imprinted gene segments repaired | Cell Stem Cell

The researchers performed gene editing again. In addition to repairing the imprinted genes, they also expanded to all areas that may be related to embryonic overgrowth. After five rounds of gene editing, abnormal symptoms such as edema of the internal organs of the orphaned mice began to ease, and about 30% of the orphaned mice successfully survived to adulthood. Finally, the researchers successfully constructed orphaned haploid embryonic stem cells carrying 20 gene edits of the imprinted segments and injected them into enucleated oocytes together with sperm. These orphaned embryos not only developed, but also successfully generated viable fetuses and fully functional placentas.

Adult orphan male mice (left) and wild-type control mice of the same age and sex | Cell Stem Cell

Orphaned male mice are significantly different from ordinary mice after birth. When ordinary mice weigh 20 grams, orphaned male mice weigh about 30 grams. And orphaned male mice show a stronger desire to explore. In the open field experiment, they frequently enter the central area, which is contrary to the habit of rodents to move along the edge. Interestingly, not only does the weight growth pattern of orphaned female mice contrast with that of orphaned male mice (they are smaller in weight), but their behavior also contrasts: in the open field experiment, orphaned female mice almost always move along the edge and rarely enter the central area. Orphaned female mice have a longer lifespan, while the lifespan of orphaned male mice is only 60% of that of ordinary mice. The study believes that these differences are likely due to residual gene imprints that have not been fully repaired in their bodies.

New research shows that the evolutionary goal of imprinted genes is not to directly prevent parthenogenesis, but more of an indirect effect: when there are two sets of paternal DNA in the body, the embryo tends to overgrow, which is biologically unsustainable and ultimately affects survival. This process is consistent with the classic conflict hypothesis: imprinted genes balance the space and resources required by regulating the development of the embryo in the mother's uterus. Maternal imprinted genes tend to "shrink" the size of the fetus to adapt to the limited space in the uterus; paternal imprinted genes increase the survival rate of offspring by "increasing" the size of the fetus. The mirror-image differences in weight, behavior, and lifespan between parthenogenetic male and female mice are the byproducts of the gene game between parents.

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