Wednesday, February 12, 2025

Worm surface chemistry reveals secrets to their development and survival

University of Nottingham

Nematode surface chemistry — image:
*Pristionchus pacificus precision predation*. Adult *P. pacificus* wildtype predating on *C. elegans* wildtype larvae that are composed of unique surface chemistry as identified using 3D-OrbiSIMS
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Credit: University of Nottingham - Veered Chauhan

A new study has revealed the clearest-ever picture of the surface chemistry of worm species that provides groundbreaking insights into how animals interact with their environment and each other. These discoveries could pave the way for strategies to deepen our understanding of evolutionary adaptations, refine behavioural research, and ultimately overcome parasitic infections.

Scientists from the University’s School of Pharmacy used an advanced mass spectrometry imaging system to examine the nematodes Caenorhabditis elegans and Pristionchus pacificus, aiming to characterise species-specific surface chemical composition and its roles in physiology and behaviour. Their results show that nematode surfaces are predominantly oily or lipid-based, forming a complex chemical landscape. The findings have been published today in the journal JACS.

Nematodes, or worms, are found in nearly every environment on Earth, including inside animals, soil, plants, seeds, water, and even humans. Infections caused by nematodes can lead to serious health conditions in severe cases.

This research was led by Dr Veeren Chauhan, an Assistant Professor in Whole Organism Analytics at the School of Pharmacy, he explained: “Nematodes are an excellent model for human biology and are considered to be some of the most completely understood animals on the planet – especially in terms of genetics, neurology and developmental biology. We share around 60-70% of our DNA with these worms so any new discoveries about them can significantly enhance our understanding of human biology and can contribute towards solving global human health challenges.

Using world-leading mass spectrometry facilities, we studied the surface chemical properties of nematodes throughout their development. This allowed us to track molecular changes in detail and observe how surface chemistry differs during development, varies between species, and, importantly, influences their interactions with one another.”

The team used the state-of-the-art 3D-OrbiSIMS instrument at the University of Nottingham to reveal that the surface chemistry of both worm species change over time and they are made up of predominantly lipids, which account for approximately 70-80% of the molecular composition.

The University of Nottingham was one of the first institutions in the world to obtain a 3D-OrbiSIMS instrument. This instrument enables an unprecedented level of mass spectral molecular analysis across a range of materials, including hard and soft matter as well as biological cells and tissues. When the surface sensitivity, high mass resolution and spatial resolution, are combined with a depth profiling sputtering beam, the instrument becomes an extremely powerful tool for chemical analysis as demonstrated in this recent work.

Dr Chauhan continues: “Discovering that these worms have predominantly oily, or lipid-based, surface is a significant step in understanding their biology. These lipid surfaces help maintain hydration and provide a barrier against bacteria, which are essential for their survival. What is also very interesting is that these lipids also appear to serve as chemical cues that influence interspecies interactions, such as predation. For example, the predatory behaviour of Pristionchus pacificus is guided by physical contact with the surface lipids of its prey, Caenorhabditis elegans, and alterations in these lipids can increase the susceptibility of the prey to predation.”

Gaining this level of understanding of the surface chemistries of these worms and how they influence interaction and survival opens up new areas of scientific discovery and could ultimately help in developing strategies to fight parasitic worms and the diseases that they cause.”

This research was conducted in collaboration with the Lightfoot Lab, led by Dr James Lightfoot, at the Max Planck Institute for Neurobiology of Behavior – caesar in Bonn, Germany. This work was funded by a Nottingham Research Fellowship (University of Nottingham), the Engineering and Physical Sciences Research Council, the Max Planck Society, and by the German Research Foundation.

Journal

JACS

DOI

10.1021/jacs.4c12519

Method of Research

Imaging analysis

Subject of Research

Animals

Article Title

Surface lipids in nematodes are influenced by development and species-specific adaptations

Article Publication Date

12-Feb-2025

Worm study shows hyperactivated neurons cause aging-related behavioral decline

Nagoya University

Head of the nematode C. elegans — image:
Head of the nematode *C. elegans* overlaid with red fluorescence of neurons
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Credit: Kentaro Noma

A study of nematodes by researchers at Nagoya University in Japan has found that aging-related decline in brain function is caused by the excessive activation of certain neurons over time, rather than a decline in neuronal activity. This finding, published in the journal Proceedings of the National Academy of Sciences, suggests that interventions aimed at reducing neuronal hyperactivation, such as dietary changes, could potentially mitigate age-related cognitive decline.

Proper brain function occurs when a large number of neurons are connected to each other and work in an appropriate way. In this sense, declines in brain function with age have generally been attributed to a decrease in the activity of neurons over time.

However, in humans, some types of neurons have been reported to become hyperactive with age. A research group led by Associate Professor Kentaro Noma of Nagoya University conducted experiments on nematodes to determine the cause-and-effect relations between the hyperactivation of neurons and the decline in brain function with age.

"In this study, we used the nematode Caenorhabditis elegans, which is only one millimeter long and has a lifespan of only two weeks. The nematodes exhibit a variety of behaviors with their 302 neurons," Noma said. "C. elegans shares many genes and mechanisms with humans. So, we thought that the cause of the decline in brain function over time in C. elegans may apply to humans."

This study took advantage of the ability of C. elegans to learn by association in a behavior called thermotaxis. In this behavior, C. elegans kept in an environment with food at 23 degrees Celsius will move toward 23 degrees when placed in an environment with a temperature gradient from 17 to 23 degrees. However, the animals will choose not to do so if kept in an environment where there is no food. This suggests that C. elegans learns to associate the presence or absence of food with the temperature of their environment.

"Our previous studies found that the brain function for associative learning in C. elegans declines over time, and we thought this was due to a decline in neuronal activity with age," said Binta Maria Aleogho, first author of the study. "In our latest study, however, we found that the activities of AFD sensory neurons and AIY interneurons, both of which are thought to be essential for associative learning, have barely changed with age."

The researchers then studied the behavior of C. elegans when each of six types of neurons thought to be involved in associative learning—the sensory neurons AWC and ASI, and the interneurons AIZ, AIB, RIA, and AIA—was removed from the brains of nematodes. Surprisingly, after removing AWC or AIA from their brains, the nematodes could move to the 23-degree location.

The researchers also measured the activities of the neurons in aged nematodes. They found that AWC and AIA are spontaneously and excessively activated with age. "This finding suggests that the hyperactivation of these two types of neurons with age disrupts the normal neuronal network, rendering them unable to carry out the thermotaxis behavior," Noma said.

"In addition, we were able to suppress neuronal hyperactivation and prevent behavioral decline in aged nematodes by changing the type of bacteria as their food source. So, we humans might be able to prevent the aging of our brains by changing our diet."

He concluded: "So far, we have tended to focus on the decline in neuronal activity with age. Our findings may lead people to focus on the hyperactivation of neurons. We will continue to study C. elegans to determine how to reduce the hyperactivation of neurons to improve brain function. We believe this will help us understand the basis of aging in brain function."

Schematic of the head of an aged C. elegans in which hyperactive neurons interfere with proper migration to the previous culture temperature

Credit

Kentaro Noma

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2412391122

Method of Research

Experimental study

Article Title

Aberrant neuronal hyperactivation causes an age-dependent behavioral decline in Caenorhabditis elegans

Wealth gap fuels health inequality for over 50s: new study reveals lifestyle divide and depression link

University of Surrey

Wealth gap fuels health inequality for over 50s: new study reveals lifestyle divide and depression link

There is a "silent emergency” brewing under our noses as research from the University of Surrey finds that there is a clear wealth gap among adults over 50 who meet physical activity and dietary guidelines. The research also found that poorer adults are nearly three times more likely to be depressed than their wealthier counterparts.

In a paper published in the Journal of Public Health, researchers from Surrey analysed recent data from over 3,000 adults aged 50-90, from the English Longitudinal Study of Ageing (ELSA), and found that while nearly 70% of older adults reported engaging in some form of physical activity, there were stark differences based on wealth.

Older adults in the highest wealth quintile were, in fact, nearly twice as likely to be physically active compared to those in the lowest wealth quintile. Similar disparities were found in fruit and vegetable consumption, with those in the highest wealth bracket reporting over 70% adherence to the ‘5-a-day' dietary guidelines, compared to just over 40% in the lowest bracket. Not meeting government guidelines for physical activity and diet has important health consequences, and the study also found a clear link to depression risk.

Dr Simon Evans, lead author of the study from the University of Surrey, said:

"There is a silent emergency brewing in our country – for older people, being in a lower wealth bracket might be a bigger barrier to good health than your age. Our research shows that poorer older adults are nearly three times more likely to experience depression and far less likely to meet government health guidelines than their wealthier peers. There is an urgent need for action to address these disparities before it’s too late."

The research found that just under 19% of participants showed significant symptoms of depression, with the highest risk among women, people living alone, smokers, and those in lower-income groups – rates of depression were around 3 times higher in the lowest wealth quintile (32.6%) compared to the highest (11.1%). Regular exercise was linked to much lower depression rates, with 30% of inactive individuals experiencing depression compared to just 13.7% of those who were active. Interestingly, eating five or more portions of fruit and vegetables daily was also associated with a lower risk of depression, with rates of 23.4% among those who didn’t meet the ‘5-a-day' guidelines versus 15.7% among those who did.

[ENDS]

Dr Simon Evans is available for interview, please contact mediarelations@surrey.ac.uk to arrange.

The full paper is available here.

An image of Dr Evans is available upon request.

Journal

Journal of Public Health

DOI

10.1007/s10389-025-02411-6

Article Title

Health‑related behaviours and depression incidence amongst UKadults aged 50+: Evidence from the English Longitudinal Studyof Ageing

Antarctica’s only native insect’s unique survival mechanism

Antarctic midge 1st reported organism using both quiescence and obligate diapause in multiple overwintering

Osaka Metropolitan University

Antarctic midges mating — image:
The Antarctic midge is the only known insect native to Antarctica.
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Credit: Yuta Shimizu / Osaka Metropolitan University

Picture an Antarctic animal and most people think of penguins, but there is a flightless midge, the only known insect native to Antarctica, that somehow survives the extreme climate. How the Antarctic midge (Belgica antarctica) copes with freezing temperatures could hold clues for humans about subjects like cryopreservation, but there remain many mysteries about the tiny insect.

One mystery appears to have been solved by an Osaka Metropolitan University-led international research team. Graduate School of Science Professor Shin G. Goto and Dr. Mizuki Yoshida, a graduate student at the time of the research who is now a postdoc at Ohio State University, found that the midge deals with the seasons during its two-year life cycle by undergoing quiescence in its first year and obligate diapause in its second.

Quiescence is a form of dormancy in immediate response to adverse conditions, and when conditions improve, the organism becomes active again. Obligate diapause is a dormant period naturally induced at a fixed time in an organism’s life cycle, a rare form seen in insects in temperate regions.

“We were able to establish a method for rearing the Antarctic midge over a period of six years to find out some of their environmental adaptation mechanisms,” Dr. Yoshida explained.

The team found that Antarctic midge larvae usually grow to their second instar by the first winter and undergo quiescence so that they can quickly resume development at any moment when it suddenly becomes warmer. As the second winter approaches, the larvae reach the final fourth instar, but they do not pupate. Instead, they enter obligate diapause so that they all emerge as adults when summer arrives. As adults, they have only a few days of life and need to find a mate, so this timing mechanism is key to their survival.

“We determined that for the Antarctic midge obligate diapause ends with the onset of low temperatures in winter so that the larvae all pupate at the same time and emerge as adults at the same time,” Professor Goto stated. “Although seasonal adaptation strategies involving overwintering multiple times using both quiescence and obligate diapause have not been reported in other organisms, we believe that insects inhabiting harsh environments such as the Arctic and high altitudes might be employing similar strategies.”

###

About OMU

Established in Osaka as one of the largest public universities in Japan, Osaka Metropolitan University is committed to shaping the future of society through “Convergence of Knowledge” and the promotion of world-class research. For more research news, visit https://www.omu.ac.jp/en/ and follow us on social media: X, Facebook, Instagram, LinkedIn.

Journal

Scientific Reports

DOI

10.1038/s41598-025-86617-4

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Obligate diapause and its termination shape the life-cycle seasonality of an Antarctic insect

Article Publication Date

12-Feb-2025

How Earth's early cycles shaped the chemistry of life

The Hebrew University of Jerusalem

A new study explores how complex chemical mixtures change under shifting environmental conditions, shedding light on the prebiotic processes that may have led to life. By exposing organic molecules to repeated wet-dry cycles, researchers observed continuous transformation, selective organization, and synchronized population dynamics. Their findings suggest that environmental factors played a key role in shaping the molecular complexity needed for life to emerge. To simulate early Earth, the team subjected chemical mixtures to repeated wet-dry cycles. Rather than reacting randomly, the molecules organized themselves, evolved over time, and followed predictable patterns. This challenges the idea that early chemical evolution was chaotic. Instead, the study suggests that natural environmental fluctuations helped guide the formation of increasingly complex molecules, eventually leading to life’s fundamental building blocks.

A new study led by Dr. Moran Frenkel-Pinter, from the Institute of Chemistry at The Hebrew University of Jerusalem, as well as Prof. Loren Williams, from the Georgia Institute of Technology, investigates how chemical mixtures evolve over time, shedding light on potential mechanisms that contributed to the emergence of life on Earth. Published in Nature Chemistry, the research examines how chemical systems can undergo continuous transformation while maintaining structured evolution, offering new insights into the origins of biological complexity.

Chemical evolution refers to the gradual transformation of molecules in prebiotic conditions, a key process in understanding how life may have arisen from non-living matter. While much research has focused on individual chemical reactions that could lead to biological molecules, this study establishes an experimental model to explore how entire chemical systems evolve when exposed to environmental changes.

The researchers used mixtures containing organic molecules with diverse functional groups, including carboxylic acids, amines, thiols, and hydroxyls. By subjecting these mixtures to repeated wet-dry cycles—conditions that mimic the environmental fluctuations of early Earth—the study identified three key findings: chemical systems can continuously evolve without reaching equilibrium, avoid uncontrolled complexity through selective chemical pathways, and exhibit synchronized population dynamics among different molecular species. These observations suggest that prebiotic environments may have played an active role in shaping the molecular diversity that eventually led to life.

“This research offers a new perspective on how molecular evolution might have unfolded on early Earth,” said Dr. Frenkel-Pinter. “By demonstrating that chemical systems can self-organize and evolve in structured ways, we provide experimental evidence that may help bridge the gap between prebiotic chemistry and the emergence of biological molecules.” Beyond its relevance to origins-of-life research, the study’s findings may have broader applications in synthetic biology and nanotechnology. Controlled chemical evolution could be harnessed to design new molecular systems with specific properties, potentially leading to innovations in materials science, drug development, and biotechnology.

Journal

Nature Chemistry

DOI

10.1038/s41557-025-01734-x

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Evolution of Complex Chemical Mixtures Reveals Combinatorial Compression and Population Synchronicity

Article Publication Date

12-Feb-2025

WAR IS ECOCIDE

Ukraine war forces planes to take longer routes, raising CO2

University of Reading

Global aviation carbon dioxide emissions increased by 1% in 2023 because planes had to fly longer routes to avoid Russian airspace, according to a new study.

After Russia invaded Ukraine in February 2022, Western airlines were banned from flying over Russia. This forced them to take much longer routes between Europe or North America and East Asia, burning more fuel in the process.

Published today (Wednesday, 12 February) in Communications Earth & Environment, the study found that detours caused by the Ukraine war led to planes using 13% more fuel on average compared to their original routes. The impact was even greater for flights between Europe and Asia, which saw a 14.8% increase in fuel consumption. Flights between North America and Asia experienced a smaller but still significant 9.8% increase.

Professor Nicolas Bellouin, currently seconded to the Institut Pierre-Simon Laplace (Sorbonne University/École Polytechnique/UVSQ) co-authored the research from the University of Reading. He said: “After the invasion of Ukraine, there was a drop in flights between Western countries and East Asia as airlines adjusted their routes. Over time, flights resumed but had to take significant detours, either flying south of Russia or over the Arctic.

“The affected flights make up about 1,100 flights per day, but the extra distance they must fly has a notable impact on aviation's overall carbon footprint. These detours added 8.2 million tonnes of CO2 to global aviation emissions in 2023.”

The research team used flight tracking data and sophisticated computer models to calculate how much extra fuel planes use on their new routes. Their analysis took into account factors like wind patterns, which can significantly affect fuel consumption.

Airspace restrictions over Libya, Syria, and Yemen were also considered by the research team. They found conflicts in each country affect between 60 and 100 flights per day. Planes avoiding Libyan airspace used 2.7% more fuel on average, while those avoiding Syria saw a 2.9

Engineered animals show new way to fight mercury pollution

Scientists use bacterial genes to enable fish and flies to break down dangerous methylmercury into diluted gas

Macquarie University

Australian scientists have found an effective new way to clean up methylmercury, one of the world’s most dangerous pollutants, which often builds up in our food and environment because of industrial activities such as illegal gold mining and burning coal. The discovery, published in Nature Communications on 12 February 2025, could lead to new ways of engineering animals to protect both wildlife and human health.

The research team from Macquarie University's Applied BioSciences, CSIRO, Macquarie Medical School, and the ARC Centre of Excellence in Synthetic Biology, has successfully genetically modified fruit flies and zebrafish to transform methylmercury into a far less harmful gas that disperses in air.

“It still seems like magic to me that we can use synthetic biology to convert the most environmentally harmful form of mercury and evaporate it out of an animal,” says synthetic biologist Dr Kate Tepper from Macquarie University, lead author on the paper.

Methylmercury causes environmental harm due to its high bioavailability and poor excretion: it can easily cross the digestive tract, the blood-brain barrier, and the placenta and becomes increasingly concentrated as it moves up through food webs to levels that can cause harm to neural and reproductive health.

The team modified the DNA of fruit flies and zebrafish by inserting variants of genes from bacteria to make two enzymes that together can convert methylmercury to elemental mercury which evaporates from the animals as a gas.

"When we tested the modified animals, we found that not only did they have less than half as much mercury in their bodies, but the majority of the mercury was in a much less bioavailable form than methylmercury," says Dr Tepper.

"The research is still in the early stages, and extensive testing is needed to make sure it's effective and completely safe," says Associate Professor Maselko.

The researchers included safety measures to ensure the modified organisms cannot spread uncontrollably in nature, and they also highlight the need for regulatory control for any real-world use.

Journal

Nature Communications

DOI

10.1038/s41467-025-56145-w

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Methylmercury demethylation and volatilization by animals expressing microbial enzymes

Article Publication Date

12-Feb-2025

COI Statement

Aspects of this research were ﬁled under patent application WO/2023/183984 by K.Tepper and M.Maselko. K.T., C.P., and M.Maselko are co-founders of EntoZyme PTY LTD. The remaining authors declare no competing interests.