Embryonic development is one of the most dynamic biological processes in nature. Cells and tissues organize and reorganize themselves following incredibly precise patterns, while remaining flexible and robust. Scientists are increasingly probing the role the physical properties of embryonic tissues—such as rigidity or stiffness—play in this process.

Researchers have captured the first atomic structures of human SMUG1, an enzyme that helps cells repair damaged DNA. The findings provide new insight into how cells recognize and remove harmful DNA bases, and may support future efforts to develop drugs that target this DNA repair pathway.

Canadian scientists have made a significant advance in understanding the mechanisms that enable embryos to properly form their limbs, thanks to new research led by Université de Montréal medical professor Marie Kmita at the Montreal Clinical Research Institute (IRCM). In findings published in the Proceedings of the National Academy of Sciences, Kmita and her team highlight the crucial role of certain molecular systems that act as true "genetic brakes," ensuring that development proceeds correctly.

Industrial oxidation chemistry is a cornerstone of modern manufacturing, accounting for nearly one-third of all chemical industrial processes. While essential for making pharmaceuticals, dyes, and many specialty chemicals, industrial oxidation typically relies on high-temperature, high-pressure processes involving toxic oxidizing agents. This has motivated scientists to look into cytochrome P450 monooxygenases (P450s) as a compelling alternative.

A team of Israeli scientists at the Hebrew University of Jerusalem has developed a novel method to significantly lower the production costs of cultivated meat. The new study demonstrates that preloading plant-derived cellulose scaffolds with growth factors supports the cost-efficient proliferation and differentiation of bovine stem cells. By binding these vital proteins directly to an anisotropic, directionally frozen framework instead of dispersing them in liquid media, this method achieves high-quality tissue development using up to 10 times fewer expensive factors. Upon multi-week cultivation and subsequent pan-frying, the cell-bound constructs show partially similar mechanical and visual responses to traditional sirloin cuts.

Rod-shaped fragments of RNA called “obelisks” were discovered in gut and mouth bacteria for the first time

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Water deficit resistance in plants has long been a topic of interest for cultivating reliable crops. Some plants can alter their above-ground structure to lock in moisture, while others develop deep, industrious roots that find hard-to-reach water sources. While such responses are obvious to the naked eye, we know little about how responses to environmental stress occur at the microscopic, cellular level.

Plastics, medicines, cosmetics—there are very few everyday products that do not rely on using fossil resources. A European research team led by Charité—Universitätsmedizin Berlin is now aiming to revolutionize this cornerstone of the chemical industry: as part of the CarboNcare project, scientists are developing bacteria that can produce important chemical base materials from sustainable methanol—thereby replacing fossil resources.

Scientists from six Asian countries have launched an ambitious 10-year effort to build synthetic cells from non-living molecules, marking the region's first coordinated push to create an artificial single-celled biological system. The roadmap, published on May 26 in Nature Biotechnology and led by the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences, was developed through the SynCell Asia Initiative, which comprises more than 100 scientists from China, Japan, South Korea, Singapore, Thailand, and Malaysia.

Cells are typically studied outside the body under controlled laboratory conditions. However, conventional flat cell culture methods do not fully reproduce the complex three-dimensional environments that cells experience in living tissues. Tiny hydrogel capsules offer one way to culture cells in a confined three-dimensional space, allowing researchers to study how cells grow, organize and interact under more tissue-like conditions. Current methods to do this come with a high cost and a set of requirements that put such research out of reach to many.

What if a process we associate with aging actually helps the body heal? A study led by Mikolaj Ogrodnik, LBI Trauma, published in Nature Cell Biology, shows that cells enter a state of senescence within minutes to hours after an injury—and that this rapid response not only plays a key role in wound healing, but also changes the paradigm of how slowly senescence was expected to arise.

Decades of reliance on the antibiotic rifampicin have fueled the rise of drug-resistant Mycobacterium tuberculosis (Mtb). But as the bacterium mutates to protect itself from the drug, it also creates new weak points that other therapies could exploit. Now, a new study published in Nature Microbiology shows that the most common rifampicin-resistance mutation slows bacterial RNA polymerase, creating vulnerabilities that future combination therapies may be able to target.

Scientists discovered that fog droplets can host living bacteria that grow and help remove harmful pollutants from the atmosphere, revealing fog as a surprisingly active microbial environment. Every breath you take may contain microscopic hitchhikers floating through the atmosphere. Scientists have known for years that bacteria drift through clouds and air currents, but new research [...]

Greenhouse gases trap heat within the atmosphere. One such gas that exists beneath the ocean floor is methane. Ice-like substances on the seafloor that contain methane, known as methane hydrates, can break apart or melt, releasing methane gas into the ocean, risking further global warming. Melting permafrost, active tectonics, daily tidal patterns, and changing sea levels can similarly trigger methane’s escape from sediments. However, scientists don’t understand how these triggers will respond to future climate change.

A team of researchers hypothesized that future global warming could actually accelerate methane’s escape into the ocean. To investigate this hypothesis, they focused on an ancient global warming event approximately 56 million years ago, called the Paleocene-Eocene Thermal Maximum or PETM. Arctic Ocean temperatures at times exceeded 20°C (68°F) during this event. These elevated temperatures serve as an analog for today’s rapidly warming conditions. 

Once methane enters seawater, its fate is largely determined by 2 sets of biological processes. Today, 90% of methane released into the ocean from the seafloor is consumed by tiny organisms called microbes via a process known as anaerobic methane oxidation. During this process, microbes consume methane alongside sulfate, producing a solid iron-sulfur mineral, pyrite. Anaerobic methane oxidation prevents methane from escaping into the atmosphere by trapping it in minerals. In this case, the ocean becomes a reservoir, or sink, for methane. 

Despite this, too much methane could overwhelm the sulfate-dependent cycle. If that occurs, a different set of microbes consumes methane alongside oxygen in a process known as aerobic methane oxidation. Aerobic methane oxidation produces carbon dioxide, a potent heat-trapping greenhouse gas that escapes from the ocean. Aerobic oxidation accounts for 10% of methane consumption in oceans today, though this could have been different in the past. 

To determine how much anaerobic versus aerobic methane oxidation occurred during the PETM, the team extracted data from sediments retrieved from the Arctic Ocean floor. As sediment piles up on the seafloor, it compacts. Scientists can drill deep into the seafloor to extract a cylindrical sample, or core, of this compacted sediment. 

The age of sediments in a core increases with depth. Therefore, younger sediments exist at the top of the core, and older sediments exist at the bottom. For this project, the team used a previously extracted core from the Arctic Ocean that contained sediments dating back 100 million years. They found 56-million-year-old sediments from the PETM at a depth of 386 meters, or 1,266 feet, in this core. 

The researchers explained that microbes leave behind unique carbon-based molecules called organic biomarkers when they decompose. These organic biomarkers accumulate in seafloor sediments. The 2 different types of methane-consuming microbes leave behind 2 different biomarkers, one for anaerobic methane oxidation and one for aerobic methane oxidation. This team measured the amount of each biomarker in the sediment core to determine which microbes were dominant during the PETM. 

The biomarker left behind from microbes performing aerobic methane oxidation is called hop(17)21-ene. The researchers noticed that the amount of hop(17)21-ene increased by a factor of 4 during the PETM. At the same time, the biomarker left behind from microbes performing anaerobic methane oxidation, called glycerol dialkyl tetraether, decreased to half. They interpreted these trends to reflect the rise of aerobic methane cycling and the shutdown of anaerobic methane cycling, respectively. They attributed this transition to the release of enough methane to overwhelm the sulfate-dependent methane cycle under warming conditions.

To estimate the amount of carbon dioxide produced by aerobic methane oxidation during the PETM, the researchers located another biomarker in the sediment core, called phytane. Phytane is produced by organisms that consume carbon dioxide during photosynthesis, and its structure preserves clues to the amount of carbon dioxide available at the time. The researchers found that during and well after the PETM, the concentration of carbon dioxide in the Arctic Ocean was 4 times greater than modern levels. They concluded that the Arctic Ocean became a prolonged source of carbon dioxide to the atmosphere, even after the PETM.

The team suggested that the uptick in aerobic methane oxidation during the PETM serves as an analog for the modern Arctic Ocean, which continues to warm rapidly in the face of modern climate change. Their results highlight how the transformation of methane into carbon dioxide poses a threat. More carbon dioxide in the atmosphere warms the air, which heats the oceans, causing more methane to escape from the seafloor and eventually be converted into additional carbon dioxide. When triggered, this feedback would continue to amplify and could become difficult to recover from.  

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Rod-shaped fragments of RNA called “obelisks” were discovered in gut and mouth bacteria for the first time

© Science Photo Library/Getty Images