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Comment by Dr. Krishna Kumari Challa on October 16, 2025 at 10:21am

Human cells activate self-destruction when viruses disrupt RNA production, study shows

Viruses are masters at taking over our cells: They disable our defenses and hijack the cellular machinery in order to multiply successfully. For example, the herpes simplex virus 1, which causes blister-like skin rashes, and influenza viruses specifically block a crucial step in gene activity in which the production of RNA molecules is completed—known as transcription termination. The blockade results in unnaturally long RNA molecules that cannot be translated into proteins. This suppresses the antiviral defense in the cells and creates optimal conditions for the viruses to multiply.

A new study published in Nature now shows that human cells are not helpless against this viral sabotage. They recognize the disruption of transcription termination as an alarm signal, activate a "self-destruction program" and sacrifice themselves—even before the virus can multiply in them. This enables them to nip the spread of the infection in the bud.

Researchers discovered that the unnaturally long RNA molecules adopt a special structure: They twist into left-turning double strands, known as Z-RNAs. These unusual RNA forms are recognized by the cellular protein ZBP1. And then the controlled cell death begins.

It is particularly noteworthy that Z-RNAs form primarily in those sections of these unnaturally long RNA molecules that originate, among other things, from remnants of previous viral infections. These otherwise silent areas of our genome are only transcribed into RNA due to the virus-related disruption of transcription termination.

Our cells therefore use these genetic remnants of ancient viral infections to detect and ward off current viral attacks.

Evolution has thus turned the tables: what once began as a viral invasion now serves as an alarm signal for the antiviral immune defense. This discovery impressively demonstrates how closely virus and host have been intertwined over millions of years—and how our cells can transform viral sabotage into highly effective protective strategies.

 Chaoran Yin et al, Host cell Z-RNAs activate ZBP1 during virus infections, Nature (2025). DOI: 10.1038/s41586-025-09705-5

Comment by Dr. Krishna Kumari Challa on October 16, 2025 at 10:16am

Differences in coexistence create new species

A simple change in species composition can impact the course of evolution: A research team shows that the presence of just one other fish species is enough to drive the emergence of new species in sticklebacks.

It has long been assumed that adaptation to different habitats plays an important role in the evolution of new species. Yet how important this influence truly is—particularly during the initial stages of the speciation process—and which ecological differences are most critical remain major questions in evolutionary research.

For the current study, the research team studied populations of threespine stickleback—small fish about the size of a finger—from lakes in western Canada. These lakes formed after glaciers from the last ice age melted less than 12,000 years ago and were then colonized by sticklebacks from the sea. While many of these lakes are environmentally similar, they differ in one aspect: in some, another fish species, the prickly sculpin, lives alongside sticklebacks, while in other lakes sculpins are absent.

This seemingly simple ecological difference—living with or without sculpins—has repeatedly pushed sticklebacks down distinct evolutionary paths: in lakes with sculpins, sticklebacks have evolved into slimmer open-water forms, while in sculpin-free lakes they have become stockier bottom-feeding specialists.

 Marius Roesti et al, A species interaction kick-starts ecological speciation in allopatry, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2506625122

Comment by Dr. Krishna Kumari Challa on October 16, 2025 at 10:13am

Electric charge connects jumping worm to aerial prey

A tiny worm that leaps high into the air—up to 25 times its body length—to attach to flying insects uses static electricity to perform this astounding feat, scientists have found.

The journal PNAS published the work on the nematode Steinernema carpocapsae, a parasitic roundworm. 

Researchers identified the electrostatic mechanism this worm uses to hit its target, and we've shown the importance of this mechanism for the worm's survival. Higher voltage, combined with a tiny breath of wind, greatly boosts the odds of a jumping worm connecting to a flying insect.

They conducted the experiments, including the use of high-speed microscopy techniques to film the parasitic worm—whose length is about the diameter of a needle point—as it leaped onto electrically charged fruit flies.

The researchers showed how a charge of a few hundred volts, similar to that generated by an insect's wings beating the air, initiates an opposite charge in the worm, creating an attractive force. They identified electrostatic induction as the charging mechanism driving this process.

Using physics, scientists learned something new and interesting about an adaptive strategy in an organism.

Ranjiangshang Ran et al, Electrostatics facilitate midair host attachment in parasitic jumping nematodes, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2503555122

Comment by Dr. Krishna Kumari Challa on October 16, 2025 at 10:05am

A rare variety of wheat with three ovaries—gene discovery could triple production

Researchers discovered the gene that makes a rare form of wheat grow three ovaries per flower instead of one. Since each ovary can potentially develop into a grain of wheat, the gene could help farmers grow much more wheat per acre. Their work is published in the journal Proceedings of the National Academy of Sciences.

The special trait of growing three ovaries per flower was initially discovered in a spontaneously occurring mutant of common bread wheat. But it wasn't clear what genetic changes led to the new trait. The UMD team created a highly detailed map of the multi-ovary wheat's DNA and compared it to regular wheat.

They discovered that the normally dormant gene WUSCHEL-D1 (WUS-D1) was "switched on" in the multi-ovary wheat.
When WUS-D1 is active early in flower development, it enlarges the flower-building tissues, enabling them to produce extra female parts like pistils or ovaries.

If breeders can control or mimic this genetic trick of activating WUS-D1, they could design new wheat varieties that grow more kernels per plant. Even small gains in the number of kernels per plant can translate into huge increases in food supply at the global scale.

Pinpointing the genetic basis of this trait offers a path for breeders to incorporate it into new wheat varieties, potentially increasing the number of grains per spike and overall yield, say the researchers. By employing a gene editing toolkit, scientists can now focus on further improving this trait for enhancing wheat yield. This discovery provides an exciting route to develop cost-effective hybrid wheat.

The discovery of WUS-D1 could also lead to the development of similar multi-ovary varieties of other grain crops.

 Adam Schoen et al, WUSCHEL-D1upregulation enhances grain number by inducing formation of multiovary-producing florets in wheat, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2510889122

Comment by Dr. Krishna Kumari Challa on October 15, 2025 at 9:16am

Men’s brains shrink more with age
Men’s brains shrink more as they age than women’s brains do, which could scupper the theory that age-related brain changes explain why women are more frequently diagnosed with Alzheimer’s disease than men. Using more than 12,500 brain scans from 4,726 people, researchers found that men experienced a greater reduction in volume across more regions of the brain over time than women did. This suggests that sex differences in brain volume don’t play a part in the development of Alzheimer’s, but “just looking at age-related changes in brain atrophy is unlikely to explain the complexities behind [the disease]”, say neurophysiologists.

 Proceedings of the National Academy of Sciences paper

https://www.pnas.org/doi/10.1073/pnas.2510486122

https://www.nature.com/articles/d41586-025-03353-5?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on October 15, 2025 at 8:51am

Fetal hearing begins to develop a little more than halfway through pregnancy, around 24 weeks into what is normally a 40-week gestation period. As the fetus grows, the uterus expands and the uterine wall thins.

Late in pregnancy, more sounds, including the mother's conversations, reach the fetus. At birth, full-term newborns recognize their mother's voice and prefer the sounds of their parents' native language to other languages, prior research has shown.

These factors suggest that listening to Mom's voice contributes to brain maturation in the latter half of a full-term pregnancy.

So in their work the researchers realized that by supplementing the sounds that premature babies hear in the hospital so they resemble what they would have heard in the womb, they had a unique opportunity to possibly improve brain development at this stage of life.

 Listening to Mom in the Neonatal Intensive Care Unit: A randomized trial of increased maternal speech exposure on white matter connectivity in infants born preterm, Frontiers in Human Neuroscience (2025). DOI: 10.3389/fnhum.2025.1673471

Part 2

Comment by Dr. Krishna Kumari Challa on October 15, 2025 at 8:49am

Mom's voice boosts language-center development in preemies' brains, study finds

Hearing the sound of their mother's voice promotes development of language pathways in a premature baby's brain, according to a new  study.

During the study, which is published in Frontiers in Human Neuroscience, hospitalized preemies regularly heard recordings of their mothers reading to them. At the end of the study, MRI brain scans showed that a key language pathway was more mature than that of preemies in a control group who did not hear the recordings. It is the first randomized controlled trial of such an intervention in early development.

This is the first causal evidence that a speech experience is contributing to brain development at this very young age.

Premature babies—born at least three weeks early—often spend weeks or months in the hospital, typically going home around their original due dates. During hospitalization, they hear less maternal speech than if they had continued to develop in utero.

Parents can't usually stay at the hospital around the clock; they may have older children to care for or jobs they must return to, for example. Preemies are at risk for language delays, and scientists have suspected that reduced early-life exposure to the sounds of speech contributes to the problem.

The researchers decided to boost preemies' exposure to their mom's voices during hospitalization. They did this by playing recordings of the mothers speaking, a total of two hours and 40 minutes a day, for a few weeks at the end of the babies' hospital stays.

Babies were exposed to this intervention for a relatively short time. In spite of that, researchers saw very measurable differences in their language tracts. It's powerful that something fairly small seems to make a big difference.

Part 1

Comment by Dr. Krishna Kumari Challa on October 15, 2025 at 8:36am

A neural basis for flocking

When animals move together in flocks, herds, or schools, neural dynamics in their brain become synchronized through shared ways of representing space, a new study by researchers  suggests. The findings challenge the conventional view of how collective motion arises in nature.

Flocking animals, such as hundreds of birds sweeping across the sky in unison, are a mesmerizing sight. But how does their collective motion—seen in many species, from swarming locusts to schooling fish and flocking birds—arise?

Researchers have developed a novel theoretical framework that integrates neurobiological principles to upend long-held assumptions about how flocking behavior emerges in nature.

In a recent article published in Nature Communications they demonstrate that flocking does not require individuals to rely on rigid behavioral rules, as is typically assumed. Instead, it can arise naturally from a simple and widespread neural architecture found across the animal kingdom: the ring attractor network.

In the new model, flocking arises because neural activity in each animal becomes linked through perception: Every individual processes its surroundings using a ring attractor—a circular network of neurons that tracks the direction toward perceived objects in space. This way, the animal can maintain bearings toward others relative to stable features in the environment. The researchers found that when many such individuals interact, their neural dynamics synchronize, giving rise to spontaneous alignment and collective movement.

This means that coordinated motion can emerge directly from navigational processes in the brain, challenging decades of theory.

The new framework shows that collective motion emerges when individuals represent the directions of others relative to stable features in their surroundings—a world-centered, or allocentric, perspective. This mechanism underlies what the authors describe as "allocentric flocking."

Mohammad Salahshour et al, Allocentric flocking, Nature Communications (2025). DOI: 10.1038/s41467-025-64676-5

Comment by Dr. Krishna Kumari Challa on October 15, 2025 at 8:32am

New lab-grown human embryo model produces blood cells

Scientists have used human stem cells to create three-dimensional embryo-like structures that replicate certain aspects of very early human development—including the production of blood stem cells. The findings are published in the journal Cell Reports.

Human blood stem cells, also known as hematopoietic stem cells, are immature cells that can develop into any type of blood cell, including red blood cells that carry oxygen and various types of white blood cells crucial to the immune system.

The embryo-like structures, which the scientists have named "hematoids," are self-organizing and start producing blood after around two weeks of development in the lab—mimicking the development process in human embryos.

The structures differ from real human embryos in many ways, and cannot develop into them because they lack several embryonic tissues, as well as the supporting yolk sac and placenta needed for further development.

Hematoids hold exciting potential for a better understanding of blood formation during early human development, simulating blood disorders like leukemia, and for producing long-lasting blood stem cells for transplants.

The human stem cells used to derive hematoids can be created from any cell in the body. This means the approach also holds great potential for personalized medicine in the future, by allowing the production of blood that is fully compatible with a patient's own body.

A post-implantation model of human embryo development includes a definitive hematopoietic niche, Cell Reports (2025). DOI: 10.1016/j.celrep.2025.116373. www.cell.com/cell-reports/full … 2211-1247(25)01144-1

Comment by Dr. Krishna Kumari Challa on October 15, 2025 at 8:24am

Flipping the switch on sperm motility offers new hope for male infertility

Infertility affects about one in six couples, and male factors account for roughly half of all cases—often because sperm don't swim well. Researchers have uncovered a key component of the "switch" that keeps the movement signal strong, offering a promising new avenue for both diagnosis and treatment. When this switch is absent, sperm slow down, and fertilization fails. By restoring that signal in the lab, the team rescued swimming and achieved healthy births in mice.

The study has been published in Proceedings of the National Academy of Sciences.

For sperm to successfully fertilize an egg, they must be able to swim, a process driven by their tail. This movement is activated by an essential signaling molecule called cyclic AMP (cAMP). While it was known that an enzyme named soluble adenylyl cyclase (sAC) produces cAMP inside sperm, the precise mechanism controlling this enzyme's stability and function remained largely a mystery.

The study focused on a protein with a previously unknown function, TMEM217, which is produced specifically in the testes. They engineered mice that could not produce TMEM217 and found that the males were completely infertile, with sperm that were almost entirely immotile. Further investigation revealed that TMEM217 partners with another protein, SLC9C1, to form a stable complex.

This complex is crucial for maintaining the presence of the sAC in mature sperm. Without TMEM217, SLC9C1 is lost and sAC is markedly reduced, causing cAMP levels to plummet and sperm motility to fail.  

In a significant breakthrough, the team took the immotile sperm from these mice and treated them with a cAMP analog—a molecule that mimics cAMP. This treatment successfully restored the sperm's movement and enabled them to fertilize eggs in vitro, leading to the birth of healthy pups.

The study has revealed a fundamental "switch" in sperm, providing a deeper understanding of sperm motility regulation. The discovery of the TMEM217-SLC9C1-sAC axis offers a new target for diagnosing unexplained cases of male infertility.

Formation of a complex between TMEM217 and the sodium-proton exchanger SLC9C1 is crucial for mouse sperm motility and male fertility, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2516573122

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