Skin has a sex: females and males do not renew their skin in the same way

Université libre de Bruxelles

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By filming skin stem cells in living mice over five months, researchers at the Université libre de Bruxelles (ULB), in collaboration with the University of Cambridge, have discovered that in females these cells renew the skin in a more coordinated way than in males. This difference, controlled by sex hormones, goes hand in hand with faster wound healing in female mice. This research could eventually pave the way for future personalized treatments taking into account patients' sex.

For a long time, differences between females and males were mainly associated with the reproductive organs. Yet organs that have nothing to do with reproduction, such as the skin, can also be shaped by sex. This question, essential for better preventing and treating inflammatory diseases and cancer, has long been underestimated by part of the scientific community.

The study, published in the prestigious journal Nature, was led by Prof. Cédric Blanpain, MD/PhD, investigator at the WEL Research Institute, director of the Laboratory of Stem Cells and Cancer and professor at the Université libre de Bruxelles, in collaboration with the team of Prof. Benjamin Simons at the University of Cambridge and other partner institutions.

The researchers used a microscopy technique that makes it possible to film cells through the skin of a living mouse. They were thus able to follow the same stem cells and their descendants for five months, an unprecedented tracking period. Having set out to understand how the skin renews itself, they uncovered an unexpected difference between females and males and then showed that sex hormones are responsible for it.

How the skin renews itself

The outer layer of the skin is constantly being renewed. At the very bottom lie the stem cells, which multiply. Some of their “daughter” cells remain stem cells; others become specialized skin cells that ensure the skin barrier function and are incapable of division (a process called differentiation), move up towards the surface and are eventually shed.

How this process is organized has been debated for decades. By filming the same areas of skin for five months, the team showed that stem cells do not turn directly into mature skin cells: they first go through an intermediate stage, during which they can only divide a limited number of times, before becoming fully specialized.

In females, stem cells are highly synchronized

Even more surprisingly, in females two “sister” cells, born from the division of the same cell, tend to make the same choice at the same time: to divide again or to specialize. Like two rowers synchronizing their strokes, they move in step. In males, each cell follows its own rhythm to a greater extent.

“We initially set out to understand how the skin renews itself, and whether there is a hierarchy with stem cells at the top. We were surprised to discover strong differences in the way stem cells renew the skin in females and males,” explains Doctor Dan Engelman, the first author of the study.

Sex hormones set the tempo

To understand where this difference comes from, the researchers turned to sex hormones. Castration of male mice, which removes the main source of male hormone called testosterone, showed that male sex hormones control the speed at which skin cells differentiate and leave the stem cell layer: after castration, male skin behaves more like female skin, whereas treatment with dihydrotestosterone (DHT), an active form of testosterone, restores the male behaviour.

Conversely, removal of the ovaries (ovariectomy) in females reduces stem cell proliferation, an effect reversed by treatment with oestradiol, the female hormone, and almost abolishes the signature of coordination between sister cells.

In short, testosterone, which is more abundant in males, controls the rate of skin cell maturation, whereas oestrogens, which are more abundant in females, drive stem cell proliferation and contribute to their coordination.

Finally, in human skin reconstructed in the laboratory, testosterone also accelerates stem cell differentiation, suggesting that this mechanism also exist in humans.

Faster wound healing in females

The researchers also observed that a wound on the skin of the back closes markedly faster in female mice, especially during the first few days. This head start is partly explained by an earlier activation of stem cells, which also work in a more coordinated way. The gap then narrows as the wound closes.

Why it matters

Doctors and researchers have long observed that wound healing, the severity of certain inflammatory diseases and the frequency of certain skin cancers differ between men and women, without really understanding why. By identifying cellular and hormonal mechanisms behind these differences in the skin, this study lifts part of the veil.

In the long run, it could pave the way for treatments that take the patient’s sex into account, for example for burns, recovery after surgery or chronic wounds in people with diabetes, which affect millions of people worldwide. It could also inspire new strategies to prevent skin cancers, which are extremely common.

These results also shed light on a long-standing debate among specialists about how the skin renews itself.

“This study is a technological tour de force, and the discovery of differences between male and female skin stem cells is fascinating and entirely unexpected. It sheds light on a series of clinical observations that previously lacked a biological explanation. It opens up a wide range of new questions, spanning from fundamental stem cell biology to clinical issues such as wound healing, cancer development, and autoimmune diseases. Sex is a parameter too often overlooked in biology and medicine. We will now investigate the differences between males and females during the formation and progression of skin cancers, as well as the molecular mechanisms responsible for these differences” says Prof. Cédric Blanpain, who led the study.

Collaborations and funding

This study is a collaboration between the team of Prof. Blanpain (ULB, Belgium) and that of Prof. Simons (University of Cambridge, UK), with the teams of Michele De Luca (University of Modena and Reggio Emilia, Italia), Yulia Shwartz (Broad CIRM Center, University of Southern California, Los Angeles, US) and Esther Hoste (VIB-Ghent University, Belgium).

This work was made possible by the support of the FNRS (including FRIA fellowships), TELEVIE, the WEL Research Institute, the Fondation contre le Cancer, the Fondation ULB, the Fonds Erasme, the Fondation Julie et Françoise Drion, the Fonds Yvonne Boël, the joint FNRS/FWO EOS (Excellence of Science) programme and the European Research Council (ERC).

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Journal

Nature

DOI

10.1103/b3pw-my97

Article Title

Sexual dimorphism in epidermal stem cell dynamics

Article Publication Date

14-Oct-2026

 

Scientists alarmed as Super El Niño collides with ‘strange uptick’ in Galapagos iguana trafficking

The only lizard in the world that can live and forage at sea may now be in a fight for survival

Simon Fraser University

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Galapagos marine iguanas soak up the sun on Marchena Island in the Galapagos Archipelago. 

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Credit: Photo by Juan José Alava

The only lizard in the world that can live and forage at sea may now be in a fight for survival. International scientists warn black-market trafficking of Galapagos marine iguanas is peaking just as the Super El Niño decimates their natural food source.

The 2026/27 El Niño event started warming equatorial waters in May, the same month Ecuadorian officials discovered four Galapagos iguanas being kept in a home near Guayaquil. Shortly after, they found a dozen more at a nearby airport, stuffed in handbags with their limbs bound. 

Another 32 were discovered tied up in small plastic containers inside a suitcase in late August. Two weeks later, the El Niño event hit ‘super’ status.

“Marine iguana populations already face threats from chemical spills and plastics pollution, and now this strange uptick in trafficking to supply the exotic pet trade is happening at the same time the Super El Niño is wiping out intertidal macroalgae,” explains Juan José Alava, marine eco-toxicologist at Simon Fraser University and co-author of a letter published in Science.

“That macroalgae is the iguana’s primary food source. They are already shrinking in size and facing mass mortality, either by starvation or by trying to swim longer distances in search of food,” he says. “This species is already very vulnerable to climate change. We wrote this letter to call attention to this added threat of trafficking.”

At least one confiscated iguana was found dead and several more have died from the smuggling attempts, but even those that survive face a long road home, says Alava, a leading researcher in ocean pollution and marine species of the Galapagos Islands. 

There are at least 11 known subspecies, each highly evolved to survive on specific islands in the Galapagos Archipelago chain; once rescued and rehabilitated, the iguanas must be DNA-tested to figure out which island they came from so they can be safely returned, he says.

Out of the Galapagos and through the loopholes

Galapagos marine iguanas are classified as Vulnerable by the International Union for Conservation of Nature, though 10 out of the 11 recognized subspecies are locally categorized as Endangered or Critically Endangered. International trade is strictly banned by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and the species is fully protected under Ecuadorian law. 

But the smuggling wasn’t detected within the Galapagos Marine Reserve, which means international traffickers are finding local ways around ecological inspection checkpoints, says Alava. 

Iguanas are likely pulled from shorelines and shallow waters around the Galapagos Islands while coastal fishing communities in Ecuador’s main coast, for example, are facing intense economic hardship and extortion from organized crime and may feel pressured to participate in this black market. 

Trafficking networks then use local logistics operators and national or international facilitators to make sure the iguanas pass through inspection points and into Ecuador, destined for exports and overseas markets in Africa, Asia, Europe, North America, and the Pacific, Alava says.

These networks obtain CITES export permits by falsely declare wild-caught Galapagos iguanas as “captive bred” in Uganda, Switzerland, Mali, and Japan—despite there being no authorized breeding facilities in these countries.

The researchers are calling on CITES to close these permitting loopholes, and for countries to strengthen oversight of the permitting system within their borders. Ecuador must also “aggressively combat and litigate organized crime and provide financial support and sustainable alternative livelihoods to coastal citizens,” the researchers write. 

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Journal

Science

DOI

10.1126/science.aek3898

Article Title

Combat Galapagos marine iguana trafficking

 

Worcester Polytechnic Institute researchers identify bamboo as fuel alternative

Bamboo-derived biofuel could rival gasoline and diesel on price, emissions; replace corn ethanol fuel production

Peer-Reviewed Publication

Worcester Polytechnic Institute

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Worcester Polytechnic Institute Professor Michael Timko 

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Credit: Worcester Polytechnic Institute

A new study from researchers, including those in Worcester Polytechnic Institute’s Department of Chemical Engineering, has found the fastest-growing plant on Earth may offer a sustainable and cost-effective alternative to petroleum-derived transportation fuels.

The researchers, including Michael Timko, the William B. Smith Professor of chemical engineering and head of the department, and Timothy Woodard, MS’23, PhD ’26, have demonstrated that bamboo could serve as a highly promising raw material for the production of sustainable liquid fuels to power vehicles, planes, and trains. The team’s study, published in the journal Sustainable Energy & Fuels, finds that bamboo can be turned into fuel at a production cost that is competitive to conventional petroleum fuels and with substantially lower greenhouse gas emissions. The study combined laboratory experiments measuring bamboo-to-biocrude conversion efficiency with economic and life-cycle assessment modeling.

“Our study suggests bamboo has a role to play in the future of fuel,” says Timko. “I think this research is especially timely and important because fuel prices are high and the transportation sector produces more greenhouse gas emissions in the U.S. than any other. Bamboo would use different land than we are using for food production, so there is no food versus fuel trade-off. Farmers win, consumers win.”

Key factors in the study are the hydrothermal liquefaction (HTL) technology that converts biomass to fuel and the choice of feedstock. Using bamboo for fuel can reduce greenhouse gasses in two ways: The process to convert it into biocrude is more efficient than when using other feedstocks, and bamboo itself captures and stores large amounts of carbon both above and below ground. Because of the plant’s fast growth even in poor soil conditions, the study finds that converting bamboo into fuel through HTL could match the level of corn-ethanol production in the U.S. while also using roughly 13% as much cultivated land. Unlike annual crops used for many biofuels, bamboo is a perennial grass that can produce large amounts of biomass with relatively low agricultural inputs. And, compared with other perennial grasses, bamboo has very low ash content (less than 1% by dry weight), meaning that the conversion process generates negligible waste.

Economic modeling indicates that bamboo-based fuel could sell for as little as $2.75 per gasoline-gallon equivalent under mature commercial-scale conditions, accounting for the money required to build and operate the fuel plant, suggesting strong economic competitiveness as the renewable-fuel industry expands.

The team’s analysis also finds that using bamboo as a fuel source creates a level of greenhouse gas emissions 26 times lower than those of conventional petroleum diesel fuel: A life-cycle assessment, considering the ability of bamboo to store large amounts of carbon in its underground rhizomes , finds producing fuel from bamboo and its use would generate a greenhouse gas intensity of 3.5 grams of carbon dioxide-equivalent per megajoule of energy.

In addition, the study suggests bamboo as a strong choice as a fuel source because it can grow faster and on smaller plots of land than other fuel feedstocks. “The U.S. has enormous land area under cultivation for corn ethanol, a fuel which is often blended into gasoline,” says Timko. “Freeing up at least some of that land could allow for more food production and reduce the burden on the environment.” The researchers also point out that bamboo can be cultivated on former industrial land or heavily farmed properties where other crops and vegetation may struggle to grow. 

“Bamboo may eventually offer industry a way to generate low-carbon liquid fuels at scale,” says Timko. “With further research and development, bamboo could be a compelling option for decarbonization in sectors that are difficult to electrify, including heavy-duty transport and aviation fuel supply chains.”

Timko and Woodard co-authored the research study with Charles Cai, associate professor in the Department of Bioproducts and Biosystems at Aalto University in Finland, and James Walters, CEO of Avos BioEnergy.

Using a reactor like the one seen in the background, bamboo can be processed into a biocrude.

Credit

Worcester Polytechnic Institute

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Journal

Sustainable Energy & Fuels

DOI

10.1039/d6se00296j 

 

Two paths to healthier soils: Scientists reveal how straw and biochar store carbon differently

Adding straw or biochar to manure can help salt-affected soils capture more carbon, but new research reveals that the two materials achieve this through fundamentally different mechanisms

Biochar Editorial Office, Shenyang Agricultural University

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Divergent pathways of straw versus biochar integration with manure to enhance SOC sequestration in coastal saline soils

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Credit: Xiaolong Bai, Jie Zhou, Ruixiao Dong, Shang Wang, Mengmeng Chen, Jing Wang, Xiaobin Li, Haoruo Li, Gilles Colinet, Hongyuan Zhang & Yuyi Li

Soils are among the planet's largest carbon reservoirs, yet salinity and land degradation threaten their ability to store carbon and support agriculture. Improving carbon storage in salt-affected farmland could therefore offer a dual benefit: restoring soil health while supporting climate change mitigation.

In a study published in Biochar, researchers from the Chinese Academy of Agricultural Sciences and collaborating institutions discovered that combining manure with straw or biochar significantly increased soil organic carbon, but through two distinct pathways. Straw primarily stimulated microbial activity and carbon transformation, while biochar improved soil structure and the physical protection of carbon.

"Both straw and biochar can improve carbon storage in saline soils, but they work in different ways," said Hongyuan Zhang, a corresponding author of the study. "Understanding these differences is essential for developing soil management strategies that improve fertility and support carbon sequestration."

The researchers conducted a two-year field experiment in China's Yellow River Delta, where high soil salinity and low organic matter levels pose major challenges to agricultural productivity. Four fertilizer treatments were compared, including conventional chemical fertilizer, manure supplementation, and manure combined with either straw or biochar.

The team examined soil carbon, microbial communities, enzyme activities, and soil pore structures to understand how each treatment influenced carbon accumulation.

Both straw and biochar combinations increased soil organic carbon by approximately 19% compared with manure alone in 2023. However, the underlying processes differed substantially.

When straw was combined with manure, it provided readily available organic materials that stimulated soil microorganisms. This increased carbon-cycling enzyme activities and promoted the accumulation of microbial necromass, the remains of dead microorganisms that contribute to soil organic matter.

Compared with manure alone, the straw treatment increased microbial necromass carbon by 10.8% and fungal necromass carbon by 11.2%. These findings suggest that microbial processing plays an important role in transforming straw-derived carbon into soil carbon.

Biochar followed a different route. Rather than primarily stimulating microbial carbon transformation, it enhanced soil aggregation and pore structure, helping protect organic carbon within larger soil particles.

The biochar treatment increased large soil aggregates by 40.9% and improved aggregate stability by 31.9%, compared with manure alone. It also increased soil porosity, creating a more favorable physical environment for carbon retention.

Microbial community analyses revealed another important distinction. Straw reduced the abundance of certain Actinobacteria-dominated microbial groups, while biochar promoted fungal groups dominated by Ascomycota that were positively associated with soil carbon storage.

Together, these findings highlight two complementary carbon sequestration strategies: biological transformation driven by straw and physical protection enhanced by biochar.

The researchers emphasize that longer-term field observations are needed to determine how these mechanisms influence carbon persistence over time.

"Our findings show that selecting organic amendments should involve more than measuring how much carbon they add to soil," Zhang explained. "Understanding how carbon is processed and protected can help guide more effective restoration of degraded agricultural land."

The study provides new insights for improving saline soil management, supporting sustainable agriculture, and strengthening soil-based carbon sequestration strategies.

 

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Journal Reference: Bai, X., Zhou, J., Dong, R. et al. Divergent pathways of straw versus biochar integration with manure to enhance SOC sequestration in coastal saline soils. Biochar 8, 139 (2026).   

https://doi.org/10.1007/s42773-026-00656-2  

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About Biochar

Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field. 

Follow us on Facebook, X, and Bluesky.  

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Journal

Biochar

DOI

10.1007/s42773-026-00656-2

Method of Research

Experimental study

Article Title

Divergent pathways of straw versus biochar integration with manure to enhance SOC sequestration in coastal saline soils

Article Publication Date

8-Oct-2026

Turning agricultural waste into soil-building substances: Manganese-modified biochar gives fungi a powerful boost

Biochar Editorial Office, Shenyang Agricultural University

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Manganese-modified biochar enhances white-rot fungi-mediated lignocellulose humification: insights from molecular transformation and multi-omics analyses

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Credit: Feng Wang, Linjie Zhang, Feng Zhou, Wenyue Wang, Yinglong Su, Dongmei Zhou, Seungkwan Hong, Min Zhan & Bing Xie

A new study reveals how manganese-modified biochar helps beneficial fungi break down agricultural residues and accelerate the formation of valuable humic substances, offering a promising approach to sustainable organic waste recycling and soil improvement.

Agricultural residues such as wheat straw are produced in enormous quantities worldwide. Although these materials contain valuable organic carbon, their tough plant fibers resist decomposition, making efficient recycling a major challenge. Now, researchers have discovered that combining manganese-modified biochar with white-rot fungi can significantly improve the conversion of agricultural waste into humic substances, which are essential for soil fertility, carbon cycling, and ecosystem health.

The study, published in Biochar, demonstrates that this combination accelerates the breakdown of plant materials while promoting the formation of more complex and stable organic compounds.

"Agricultural waste is not simply something to dispose of. It is a valuable carbon resource that can be transformed into materials that support healthier soils," said the research team. "Our findings reveal how manganese-modified biochar can work together with beneficial fungi to make this transformation more efficient."

Humic substances are important components of soil organic matter. They help improve soil structure, support nutrient retention, and regulate carbon cycling. However, their natural formation is slow. Accelerating this process, known as humification, could provide new opportunities to recycle agricultural residues into valuable soil amendments.

To investigate this possibility, researchers combined manganese-modified biochar, produced from bamboo-derived biochar, with the white-rot fungus Phanerochaete chrysosporium. They then conducted a 35-day fermentation experiment using wheat straw.

The results were striking. With 5% manganese-modified biochar, lignin degradation increased by 93.4%, cellulose degradation by 77.0%, and hemicellulose degradation by 30.9% compared with the fungus-only control. Even more importantly, humic acid content increased by 47.7%, while an indicator of humic substance polymerization rose by 112.4%.

These improvements suggest that the treatment not only accelerates plant fiber decomposition but also promotes the formation of more complex humic materials.

To understand the underlying mechanisms, the researchers combined advanced molecular analysis, interpretable machine learning, and multi-omics techniques.

They discovered that manganese-modified biochar enhances fungal growth and stimulates enzymes responsible for breaking down resistant plant fibers. Manganese-associated oxidation reactions also contribute to this process, helping release smaller organic molecules that serve as building blocks for humic substances.

Molecular analysis further revealed that the treatment promotes specific chemical transformations, including deamination, dealkylation, and lignin breakdown. These changes favor the formation of more aromatic, oxygen-rich, and structurally complex humic-like substances, particularly through pathways involving polyphenols and quinones.

Meanwhile, gene expression and metabolite analyses showed enhanced activity in pathways associated with plant fiber degradation and the production of humification precursors.

Together, these findings reveal a coordinated process in which biochar, manganese, and fungi work synergistically to accelerate organic matter transformation.

The researchers believe this strategy could support more efficient recycling of lignocellulose-rich agricultural wastes and the development of sustainable soil amendment technologies.

However, further research is needed to evaluate manganese release, long-term environmental safety, and economic feasibility under practical operating conditions.

By uncovering the molecular mechanisms behind accelerated humification, this study provides a scientific foundation for transforming agricultural residues into valuable organic resources and advancing sustainable waste management.

 

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Journal Reference: Wang, F., Zhang, L., Zhou, F. et al. Manganese-modified biochar enhances white-rot fungi-mediated lignocellulose humification: insights from molecular transformation and multi-omics analyses. Biochar 8, 140 (2026).   

https://doi.org/10.1007/s42773-026-00659-z   

=== 

About Biochar

Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field. 

Follow us on Facebook, X, and Bluesky.  

---

Journal

Biochar

DOI

10.1007/s42773-026-00659-z

Method of Research

Experimental study

Article Title

Manganese-modified biochar enhances white-rot fungi-mediated lignocellulose humification: insights from molecular transformation and multi-omics analyses

Article Publication Date

9-Oct-2026