What caused this megatooth shark’s massive toothache?

Peer-Reviewed Publication

NORTH CAROLINA STATE UNIVERSITY

 

IMAGE: ARTISTIC RECONSTRUCTION OF OTODUS MEGALODON FEEDING UPON AN ANCIENT SWORDFISH ~11 - 3.7 MILLION YEARS AGO. A PUNCTURE INJURY TO THE TOOTH GUM SUCH AS THIS MAY HAVE CAUSED GEMINATION OF THE DEVELOPING TOOTH BUDS. view more 

CREDIT: IMAGE: JORGE GONZALEZ

Did the world’s largest prehistoric shark need an orthodontist, or did it just have a bad lunch? 

Researchers from North Carolina State University and the North Carolina Museum of Natural Sciences examined a deformed tooth from an Otodus megalodon shark in a search for the root cause: was it developmental, or related to feeding? The work could give paleontologists more insight into the developmental processes associated with tooth injury in ancient sharks, as well as feeding behavior.

At issue is an abnormality referred to as double tooth pathology, in which a single tooth appears “split.” There are several possible causes: during tooth development two tooth buds can fuse into one or one tooth bud can split into two (a process called gemination). Gemination and fusion can be caused by disease, genetics or physical injury to the tooth bud.

“We don’t have a lot of data on double tooth pathologies in ancient shark species,” says Harrison Miller, former NC State undergraduate student and corresponding author of a paper describing the work. “So this was an opportunity to fill in those gaps – and perhaps learn more about the sharks in the process.”

The researchers examined three abnormal teeth: one 4-inch tooth from O. megalodon, an apex predator the size of a school bus that ruled the seas in the Miocene and early Pliocene periods (from 11 to 3.7 million years ago); and two from Carcharhinus leucas, a much smaller bull shark species that lived during the same period and still roams the seas today.

All three oddly-shaped teeth displayed a form of double tooth pathology. The researchers compared the teeth to normal teeth from both species and performed nano-CT imaging of the deformed teeth so that they could examine what was going on inside.

While the pathological teeth did have more internal canals than normal teeth – confirming either the incomplete splitting or joining of two teeth during development – the researchers were unable to definitively establish a developmental cause.

“Part of the difficulty was in applying terminology from work in humans and other mammals to sharks,” says Haviv Avrahami, NC State doctoral student and paper co-author.

“Sharks have cartilaginous skeletons, not boney skeletons, so preservation of their jaws is rare in the fossil record, and usually, we only find the individual isolated teeth. Additionally, sharks have different mechanisms for tooth development – they have continuous tooth replacement, so you can’t look at what is happening in the rest of the jaw to rule out fusion or gemination.”

Given what the researchers know about this kind of pathology in modern shark teeth, however, they lean toward feeding-related injury as a more probable cause.

“With O. megalodon in particular, the current understanding is that they fed mostly on whales,” Avrahami says. “But we know that tooth deformities in modern sharks can be caused by something sharp piercing the conveyor belt of developing teeth inside the mouth. Based on what we see in modern sharks, the injury was most likely caused by chomping down on a spiny fish or taking a nasty stab from a stingray barb.”

“We also know that O. megalodon had nesting grounds around Panama, and that relatives of modern stingray species also inhabited that area,” Harrison says. “And these spines can get very thick. So a tooth injury of this type could indicate that O. megalodon was more of a generalist predator – and that this O. megalodon in particular just had a bad day.”

Lindsay Zanno, head of paleontology at the N.C. Museum of Natural Sciences, associate research professor at NC State and co-author of the research, agrees.

“When we think of predator-prey encounters, we tend to reserve our sympathy for the prey, but the life of a predator, even a gigantic megatooth shark, was no cakewalk either.” 

The work appears in PeerJ, and was made possible by Mark Kostich’s donation of the pathological O. megalodon tooth (NCSM 33639) to the Paleontological Collections of the N.C. Museum of Natural Sciences.

“We’re incredibly grateful to Mark for gifting this specimen to the museum so we could learn more about these ancient animals,” Zanno says. “So many important fossils are hidden away in private collections, where they are unable to shed new light on our wondrous world.”

CAPTION

Normal versus deformed O. megalodon and C. leucas teeth.

CREDIT

Photo: Matthew Zeher

-peake-

Note to editors: An abstract follows.

“Dental pathologies in lamniform and carcharhiniform sharks with comments on the classification and homology of double tooth pathologies in vertebrates”

DOI:  10.7717/peerj.12775

Authors:  Harrison Miller, Haviv Avrahami, Lindsay Zanno, North Carolina State University and North Carolina Museum of Natural Sciences
Published: May 11, 2022 in PeerJ

Abstract:
Double tooth pathologies are important indicators of trauma, disease, diet, and feeding biomechanics, and are widely documented in mammals.  However, diagnosis of double tooth pathologies in extinct non-mammalian vertebrates is complicated by several compounding factors including: a lack of shared terminology reflecting shared etiology, inconsistencies in definitions and key features within and outside of mammals (e.g., gemination, fusion, twinning, concrescence); differences in tooth morphology, heterodonty, regeneration, and implantation between mammals and non-mammalian vertebrates; and the unmet need for diagnostic criteria that can be applied to isolated teeth, which are common in the fossil record.

Here we report on double tooth pathologies in the lamniform and carcharhiniform Cenozoic sharks Otodus megalodon (NCSM 33639) and Carcharhinus leucas (NCSM 33640, 33641).  All three teeth bear a singular bifid crown with mirrored halves and abnormal internal microstructure—a single, bifurcating pulp cavity in C. leucas and a more than tripling of vessels in O. megalodon (from two to seven main ascending canals).  We identify these abnormalities as likely examples of gemination due to their symmetry, which rules out fusion of tooth buds in one tooth file in different developmental stages in polyphyodont taxa; however, we note that incomplete forms of mesiodistal tooth fusion can be morphologically indistinguishable from gemination, and thus fusion cannot be rejected.  We further compile and recategorize, when possible, the diversity of tooth pathologies in sharks.

The identification of double tooth pathologies in O. megalodon and C. leucas has paleobiological implications.  Such pathologies in sharks are largely hypothesized to stem from trauma to developing tooth buds.  Carcharhinus leucas is known to feed on prey documented to cause feeding-related oral traumas (e.g., rays, sawfish, spiny fish, and sea urchins).  However, O. megalodon, is considered to have largely fed on marine mammals, and perhaps turtles and/or fish, raising the possibility that the dietary diversity of this species is, as of yet, underappreciated.

The genetic underpinnings of ​​tooth morphogenesis and regeneration is highly conserved throughout vertebrate evolution, suggesting a homologous framework can be established.  However, more research is needed to link developmental, paleobiological, and/or paleoenvironmental factors to gemination/fusion in polyphyodont taxa.  We argue that the definitions and diagnostic criteria for dental pathologies in vertebrates require standardization in order to advance macroevolutionary studies of feeding trauma in deep time.

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JOURNAL

PeerJ

DOI

10.7717/peerj.12775 

METHOD OF RESEARCH

Imaging analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Dental pathologies in lamniform and carcharhiniform sharks with comments on the classification and homology of double tooth pathologies in vertebrates

ARTICLE PUBLICATION DATE

11-May-2022

How shark teeth can decipher evolutionary processes

Tooth shapes of the tiger shark: Already the embryo changes - and swallows - its teeth

Peer-Reviewed Publication

UNIVERSITY OF VIENNA

 

IMAGE: TIGER SHARK (© DIRK KRÜSSMANN view more 

CREDIT: © DIRK KRÜSSMAN

From embryo to turtle cracker: a team led by palaeobiologist Julia Türtscher from the University of Vienna studied the multiple changes in tooth shape in the tiger shark. The study, recently published in the Journal of Anatomy, is also central in drawing conclusions about extinct species from the myriad of preserved shark teeth in the field of palaeontology.

Cartilaginous fishes, i.e. sharks, skates and rays possess a so-called revolver dentition: as soon as they lose a tooth, a new one follows, throughout their entire lives. "Accordingly, we have an incredible amount of teeth from both living and fossil cartilaginous fishes, which we can use to investigate when and how which species emerged or died out again," explains Julia Türtscher from the Department of Palaeontology at the University of Vienna. A particular challenge in this type of research is: In most shark species, the shape of the teeth changes over the course of their lives.

Multiple tooth shapes make the analysis more difficult

"This so-called heterodonty, i.e. the occurrence of different tooth shapes in the same jaw, has proven to be one of the greatest challenges for these analyses, because systematic knowledge is scarce in this area so far," says the scientist. Although numerous shark species are discovered and described each year, detailed descriptions of tooth shapes and heterodonty patterns are scarce or poorly known for most species. 

For the tiger shark, this gap has now been closed with a study that was conducted at the Department of Palaeontology of the University of Vienna and published in the Journal of Anatomy at the end of April. Using geometric morphometrics on teeth of the tiger shark Galeocerdo cuvier, Julia Türtscher and her colleagues analysed and described in detail the tooth shapes for its four different developmental stages, from embryo to adult.

"Our results show that the shape of shark teeth changes gradually and subtly during the shark's life: The teeth become larger on the one hand and more complex on the other" , Türtscher says. As such the teeth of these sharks exhibit multiple serrations, and each of these serrations is serrated again – secondarily – in adult animals. This complex structure allows adult tiger sharks to feed on an incredibly wide range of prey: They can even cut through turtle shells with ease, as well as through large prey such as other sharks or marine mammals. 

The younger and smaller tiger sharks, on the other hand, have only simple serrated teeth: They mainly feed on smaller fish, for which this additional cutting aid is not necessary. 

Tiger shark embryos already form teeth in the womb

The present study also provides the first comprehensive description of the tooth form of tiger shark embryos: According to this study, the embryos already form teeth in the mother's womb, although initially without serrations. Even before birth, however, the permanent change of teeth begins and the newly formed teeth show the first primary serrations. "This means that the first teeth are even changed in the womb – and swallowed in the process" , Türtscher explains.

The larger the animals grow, the larger the teeth become and the more primary serrations are added. Secondary serrations, however, develop relatively late, when the animals have reached a considerable size. "There generally seems to be a correlation between double-serrated teeth and large body size: Tiger sharks are among the largest predatory sharks in our oceans, with a maximum length of 5.5 meters. Moreover, we also see in their extinct relatives that the large species had double-serrated teeth, while smaller species only had single serrations" , explains second author Patrick L. Jambura from the Department of Palaeontology at the University of Vienna.

"Overall, the present study contributes significantly to our knowledge of dental characteristics during the evolution of the tiger shark – thus providing a basis for further morphological and genetic studies of tooth variation in sharks – and will certainly help to unravel the many developmental and evolutionary processes of present and past cartilaginous fishes" , says Jürgen Kriwet, Head of the Evolutionary Morphology Group at the Department of Palaeontology.

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JOURNAL

Journal of Anatomy

DOI

10.1111/joa.13668 

ARTICLE TITLE

Heterodonty and ontogenetic shift dynamics in the dentition of the tiger shark Galeocerdo cuvier (Chondrichthyes, Galeocerdidae)

Jellyfish’s stinging cells hold clues to biodiversity

Peer-Reviewed Publication

CORNELL UNIVERSITY

ITHACA, N.Y. -- The cnidocytes – or stinging cells – that are characteristic of sea anemones, hydrae, corals and jellyfish, and make us careful of our feet while wading in the ocean, are also an excellent model for understanding the emergence of new cell types, according to new Cornell research.

In new research published in the Proceedings of the National Academy of Sciences on May 2, Leslie Babonis, assistant professor of ecology and evolutionary biology in the College of Arts and Sciences, showed that these stinging cells evolved by repurposing a neuron inherited from a pre-cnidarian ancestor.

“These surprising results demonstrate how new genes acquire new functions to drive the evolution of biodiversity,” Babonis said. “They suggest that co-option of ancestral cell types was an important source for new cell functions during the early evolution of animals.”

Understanding how specialized cell types, such as stinging cells, come to be is one of the key challenges in evolutionary biology, Babonis said. For nearly a century, it’s been known that cnidocytes developed from a pool of stem cells that also gives rise to neurons (brain cells), but up to now, no one knew how those stem cells decide to make either a neuron or a cnidocyte. Understanding this process in living cnidarians can reveal clues about now cnidocytes evolved in the first place, Babonis said.

Cnidocytes (“cnidos is Greek for “stinging nettle”), common to species in the diverse phylum Cnidaria, can launch a toxic barb or blob or enable cnidarians to stun prey or deter invaders. Cnidarians are the only animals that have cnidocytes, but lots of animals have neurons, Babonis said. So she and her colleagues at the University of Florida’s Whitney Lab for Marine Bioscience studied cnidarians – specifically sea anemones – to understand how a neuron could be reprogrammed to make a new cell.

“One of the unique features of cnidocytes is that they all have an explosive organelle (a little pocket inside the cell) that contains the harpoon that shoots out to sting you,” Babonis said. “These harpoons are made of a protein that is also found only in cnidarians, so cnidocytes seem to be one of the clearest examples of how the origin of a new gene (that encodes a unique protein) could drive the evolution of a new cell type.”

Using functional genomics in the starlet sea anemone, Nematostella vectensis, the researchers showed that cnidocytes develop by turning off the expression of a neuropeptide, RFamide, in a subset of developing neurons and repurposing those cells as cnidocytes. Moreover, the researchers showed that a single cnidarian-specific regulatory gene is responsible both for turning off the neural function of those cells and turning on the cnidocyte-specific traits.

Neurons and cnidocytes are similar in form, Babonis said; both are secretory cells capable of ejecting something out of the cell. Neurons secrete neuropeptides – proteins that rapidly communicate information to other cells. Cnidocytes secrete poison-laced harpoons.

“There is a single gene that acts like a light switch – when it’s on, you get a cnidocyte, when it’s off you get a neuron,” Babonis said. “It’s a pretty simple logic for controlling cell identity.”

This is the first study to show that this logic is in place in a cnidarian, Babonis said, so this feature was likely to regulate how cells became different from each other in the earliest multicellular animals.

Babonis and her lab plan future studies to investigate how widespread this genetic off/on switch is in creating new cell types in animals. One project, for example, will investigate whether a similar mechanism drives the origin of the novel skeleton-secreting cells in corals.

This research was supported by the National Science Foundation and NASA.

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2113701119 

Smaller female North Atlantic right whales have fewer calves: Declining body size may contribute to low birth rates

Aerial photos reveal that body size of North Atlantic right whales is related to the number of calves they produce.

Peer-Reviewed Publication

NOAA FISHERIES WEST COAST REGION

 

IMAGE: NORTH ATLANTIC RIGHT WHALE CATALOG #3560 ‘SNOW CONE’ SIGHTED DECEMBER 2, 2021 ENTANGLED AND WITH A NEW CALF. view more 

CREDIT: FLORIDA FISH AND WILDLIFE CONSERVATION COMMISSION UNDER NOAA PERMIT 20556.

The declining body size of North Atlantic right whales may have critical consequences for the future of the species. New research shows that smaller females produce fewer calves. 

Earlier research showed that North Atlantic right whales are declining in size, in part due to frequent entanglements in fishing gear. The new findings suggest that reducing the impacts of such sub-lethal stresses could help the population to grow.

“Smaller females appear to have less capacity to raise calves as frequently as larger whales,” said Joshua Stewart, a research biologist with NOAA Fisheries’ Southwest Fisheries Science Center, who collaborated with other researchers from Oregon State University, Woods Hole Oceanographic Institution, the New England Aquarium, and SR3 on the findings. “Their smaller size means they may take longer to recover from the energetic cost of giving birth, especially in light of other stresses on the population.”

The research underscores the importance of expanding and enforcing protections under the Marine Mammal Protection Act and Endangered Species Act. NOAA Fisheries has designated North Atlantic right whales one of its Species in the Spotlight, in need of focused recovery actions.

 

Aerial Photos Show Relationship Between Body Size and Reproduction

Scientists took body measurements from high-resolution aerial photographs, collected over two decades, using airplanes and drones to track the sizes of North Atlantic right whales. “We were able to measure whales by flying a camera high above them, essentially giving them a health check without them knowing we were there,” said John Durban, a co-author formerly at the Southwest Fisheries Science Center and now at Oregon State University. 

Scientists examined the aerial photos of 41 female North Atlantic right whales taken from 2000 to 2019, comparing their sizes with their reproductive histories. The relationship showed that smaller whales produced fewer offspring per reproductive year. The birth rate of the population, which now numbers less than 350 animals, is already at a 40-year low. 

The size of the mother is important for baleen whale reproduction. Larger maternal size and good condition are associated with larger and more robust calves. The new study found that larger female North Atlantic right whales also appear to have more young over the course of their reproductive years. This suggests that declining body sizes are a potential contributor to low birth rates over the past decade, which may limit the population’s ability to recover.

  

CAPTION

The declining body size of North Atlantic right whales may have critical consequences for the future of the species because smaller females produce fewer calves, new research shows. Aerial photos from the study show that the whales’ body size is related to the number of calves they produce.

CREDIT

Michael Moore and Carolyn Miller, under NMFS permit #21371

Right Whales Face Many Human-Caused Threats

“After decades of research on this species, we have learned about the stressors right whales face and, with this study, have gained further insights into how these stressors are affecting their reproduction,” said Amy Knowlton, Senior Scientist in the New England Aquarium’s Right Whale Research Program and coauthor of the study. “The remedies to address these threats are clear: shifting how humans operate in the ocean so that they do not inadvertently harm whales. That means adapting to weaker ropes used for fishing and ultimately ropeless fishing gear as well as broader areas of vessel speed restrictions in the right whale’s range. With these changes, we could reverse the decline we are witnessing in this species.” 

The New England Aquarium curates the North Atlantic Right Whale Catalog and monitors human impacts and their effects on the health of the whales using more than a million photographs. Such high-resolution information is rare for marine species and these detailed databases, maintained since the 1980s, were essential to this study.

Other hard-to-observe factors undoubtedly also influence reproduction and fecundity in North Atlantic right whales beyond female body length. These include:

• Prey availability

• Climate impacts on the main feeding grounds

• Maternal health 

“Sublethal stressors such as acoustic, vessel, and entanglement trauma, drain energy acquired by feeding, diverting it from calf productivity,” said Michael Moore, Senior Scientist at the Woods Hole Oceanographic Institution, and a co-author of the study. 

“By identifying potential mechanisms that are contributing to their reduced birth rates, we can highlight tangible opportunities for interventions,” said Stewart. “Doing everything we can to relieve pressure on the population and help support their recovery and resiliency will become increasingly important in the face of a rapidly changing ocean." 

  

CAPTION

An adult North Atlantic right whale mother that brought her young calf from the calving grounds of the coast of Florida and Georgia to coastal waters of Cape Cod Bay in April 2019. Image taken with a remotely controlled drone at non-invasive altitude of at least 130ft above the whales.

CREDIT

Jacob Barbaro and Brandon Tao, under NMFS permit # 21371

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JOURNAL

Marine Ecology Progress Series

DOI

10.3354/meps14040 

METHOD OF RESEARCH

Observational study

ARTICLE TITLE

Larger females have more calves: Influence of maternal body length on fecundity in North Atlantic right whales

ARTICLE PUBLICATION DATE

12-May-2022

SFU researchers mapping landslides that could wipe out Fraser River salmon

Reports and Proceedings

SIMON FRASER UNIVERSITY

A team of researchers from Simon Fraser University have returned to the scene of a massive 2018 landslide as part of a project aimed at preventing future extinction-level events.

On Nov. 1, 2018, the Big Bar landslide in British Columbia blocked the Fraser River, prevented salmon from getting back to their spawning grounds in the Upper Fraser Basin and threatened the future of the species.  

Remediation efforts are still ongoing, but researchers led by SFU are back at Big Bar to map the effects of the slide. Their work is part of a larger project aimed at assessing and mitigating the risk of landslides to critically important salmon in the Fraser River. 

“The 2018 landslide raised the issue that I think a lot of people knew might be possible, but no one really thought too much about: that if there was a landslide lower in the Fraser Basin, it would wipe out and cause the Fraser salmon to become extinct,” says Jeremy Venditti, director of SFU’s School of Environmental Science and principal investigator on the project. “We tend to think about landslides as being natural hazards in the sense that they can affect people. We don’t think of them as the sorts of events that can wipe out populations of plants and animals, but they can.”  

The federal and provincial governments announced funding last summer for Venditti and his team but some of the fieldwork was delayed by landslides in B.C. last fall, further highlighting the urgency of the project.  

The Big Bar location was a previous field site for Venditti’s team so they’ll be comparing their measurements from 2009 to now, to see how the 2018 slide changed the river and to understand how to better predict these types of events.  

The team will map the locations of past landslides using Light Detection and Ranging (LiDAR) data and surface exposure dating to establish a chronology of river blockages that can be compared to proxies of salmon abundance in the Fraser Basin.   

The project team includes experts in natural hazards, geomorphology, remote sensing, salmon migration and population genetics. Traditional Indigenous perspectives and oral history are also integral to the project. 

They will then identify sites of potential future impacts using a combination of riverbed surveys and bank topography, and LiDAR mapping to identify sites that require further geotechnical assessment. 

Possible mitigation could include engineering solutions, like fishways that can be built to help fish get over blocked passages in the event of a slide. 

“Our goal is to determine where the next landslide that can threaten salmon is going to happen,” says Venditti. “We enter this understanding landslides, understanding rivers and understanding how fish migrate, and have a team that’s excited to conserve and restore Fraser River salmon.” 

Other partners in this project include researchers from University of Northern British Columbia, University of Victoria, Durham University, University of Massachusetts Amherst, the Department of Fisheries and Oceans, Fraser Basin Council, the Hakai Institute, Fraser Salmon Management Council and Indigenous communities. 

Chemists synthesize psychotropic compound from rainforest tree

Scripps Research scientists found the chemical binds to opioid receptors in the brain and may have utility as an antidepressant or anti-anxiety drug

Peer-Reviewed Publication

SCRIPPS RESEARCH INSTITUTE

LA JOLLA, CA—The bark of the Galbulimima belgraveana tree, found only in remote rainforests of Papua New Guinea and northern Australia, has long been used by indigenous people for both healing and ceremony. A tea brewed from the bark not only induces a dreamlike state but is said to ease pain and fever. To probe these effects, researchers have isolated more than 40 unique chemicals from the tree bark but have struggled to reproduce the compounds in the lab or study their biology.

Now, Scripps Research scientists have developed a method to synthesize one of these chemicals known as GB18. Their approach, described online in the journal Nature on May 12, 2022, includes a new type of reaction that could be useful in synthesizing other chemicals. It also let them produce enough GB18 to study its effects on human brain cells and discover that the chemical binds to opioid receptors—the same molecules targeted by many painkillers. While opioid painkillers activate these receptors, however, GB18 turns them off—a function that some researchers hypothesize could be useful in treating depression and anxiety.

“This goes to show that Western medicine hasn’t cornered the market on new therapeutics; there are traditional medicines out there still waiting to be studied,” says senior author Ryan Shenvi, PhD, a professor of chemistry at Scripps Research. “Our hope is that we can turn GB18 into a useful medicine.”

In the 1950s, Galbulimima belgraveana caught the attention of Australian researchers, who began isolating and studying its chemicals, called GB alkaloids. Some GB alkaloids were found to decrease smooth muscle spasm. Some increased heart rate, whereas others decreased it. A structural outlier, GB18, affected mouse behavior and appeared to be psychotropic. But without the ability to recreate the compounds in the lab, it was difficult to further pursue their potential therapeutic value.

While some members of the Shenvi lab recently worked out ways to synthesize other GB alkaloids—described in Science in March 2022—Scripps graduate student Stone Woo tackled GB18. Its structure was particularly tricky, with a chemical ring tucked in a hard-to-access pocket, like a mug handle attached to the inside of a cup instead of the outside. Woo discovered a series of chemical steps, however, that could produce the desired structure, exactly mimicking the structure of GB18 found naturally in Galbulimima belgraveana bark.

“Stone was able to devise this beautiful choreography for bringing together small chemicals to assemble the complex constellation that is GB18,” explains Shenvi. “He developed a way to build this ring motif that is unprecedented.”

The method that Woo devised, in fact, let him control which side of GB18 the ring could be tacked on to—an innovation with implications for creating variants of GB18 as well as for carrying out other chemical syntheses involving similar rings.

“The way we were able to efficiently assemble these molecular connections could prove useful in other contexts,” says Woo.

Once the researchers had a means to synthesize GB18, they produced enough of it to use in screening experiments conducted through the National Institute of Mental Health Psychoactive Drug Screening Program, run by Professor Bryan Roth of UNC Chapel Hill. These screens revealed that GB18 bound to two different opioid receptors in the brain. These receptors had never before been identified as targets of any GB alkaloids and represent the first new receptors linked to Galbulimima belgraveana activity in more than 35 years.

Now, the researchers are further studying the exact biological impact of GB18’s binding to the opioid receptors. While opioid drugs involved in the ongoing overdose epidemic will activate these receptors, GB18 seems to shut them off. Shenvi says that may make GB18 useful as an antidepressant or anti-anxiety drug, but more work is needed to adapt it to human use.

Shenvi and Woo are the only authors of the study “Synthesis and target annotation of GB18.” A provisional patent for GB18 has been filed by both authors.

This work was supported by funding from the National Institutes of Health (R35GM122606; S10 OD025208), the National Science Foundation (CHE 1856747) and the Skaggs Graduate School.

 

About Scripps Research

Scripps Research is an independent, nonprofit biomedical institute ranked the most influential in the world for its impact on innovation by Nature Index. We are advancing human health through profound discoveries that address pressing medical concerns around the globe. Our drug discovery and development division, Calibr, works hand-in-hand with scientists across disciplines to bring new medicines to patients as quickly and efficiently as possible, while teams at Scripps Research Translational Institute harness genomics, digital medicine and cutting-edge informatics to understand individual health and render more effective healthcare. Scripps Research also trains the next generation of leading scientists at our Skaggs Graduate School, consistently named among the top 10 US programs for chemistry and biological sciences. Learn more at www.scripps.edu.

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JOURNAL

Nature

Water makes tree branches droop at night

Peer-Reviewed Publication

UNIVERSITY OF EASTERN FINLAND

Terrestrial laser scanning data show that trees move their branches in a diurnal pattern, settling down for the night – as if falling asleep. So far, however, researchers have been uncertain as to why this happens.

A new study utilising time-series of terrestrial laser scanning measurements shows that changes in the water status of leaves and branches causes branches to move downward at night, up to 20 cm depending on the tree species. Leaves and branches replenish their water storage during the night, increasing their weight and causing them to droop down. Terrestrial laser scanning is a remote sensing technique that can produce a 3D representation of the surroundings with millimetre accuracy. With repeated measurements, it is possible to study small structural changes in the environment, such as the movement of branches.

“By monitoring the movement of tree branches, we can gain insight into how water moves inside the tree. Climate change reduces the availability of water and increases drought stress, so it is important to understand the movement of water in trees in order to understand changes in forest health,” Postdoctoral Researcher and the lead author of the article Samuli Junttila from the University of Eastern Finland says.

In the laboratory, the researchers found that tree branch position followed changes in tree water status also over a longer time period. These findings also have practical applications. For example, laser scanning could be used to monitor plant water status in a greenhouse to automate watering regimes and save valuable resources.

The study was conducted at the University of Eastern Finland in collaboration with the Finnish Geospatial Research Institute and the University of Helsinki. The study was conducted within the UNITE Flagship Programme funded by the Academy of Finland.

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JOURNAL

Forests

DOI

10.3390/f13050728 

ARTICLE TITLE

Tree Water Status Affects Tree Branch Position

Climate change increases risks of tree death

Peer-Reviewed Publication

UNIVERSITY OF UTAH

 

IMAGE: STRESSED FOREST IN THE WESTERN US view more 

CREDIT: WILLIAM ANDEREGG

Planting a tree seems like a generally good thing to do for the environment. Trees, after all, take in carbon dioxide, offsetting some of the emissions that contribute to climate change.

But all of that carbon in trees and forests worldwide could be thrown back into the atmosphere again if the trees burn up in a forest fire. Trees also stop scrubbing carbon dioxide from the air if they die due to drought or insect damage.

The likelihood of those threats impacting forests is increasing nationwide, according to new research in Ecology Letters, making relying on forests to soak up carbon emissions a much riskier prospect.

“U.S. forests could look dramatically different by the end of the century,” says William Anderegg, study lead author and associate professor in the University of Utah School of Biological Sciences. “More severe and frequent fires and disturbances have huge impacts on our landscapes. We are likely to lose forests from some areas in the Western U.S. due to these disturbances, but much of this depends on how quickly we tackle climate change.”

Wildfire, drought and insects 

The researchers modeled the risk of tree death from fire, climate stress (heat and/or drought) and insect damage for forests throughout the United States, projecting how those risks might increase over the course of the 21st century.

See their findings in an interactive map here.

By 2099, the models found, that United States forest fire risks may increase by between four and 14 times, depending on different carbon emissions scenarios. The risks of climate stress-related tree death and insect mortality may roughly double over the same time.

But in those same models, human actions to tackle climate change mattered enormously—reducing the severity of climate change dramatically reduced the fire, drought and insect-driven forest die-off.

“Climate change is going to supercharge these three big disturbances in the U.S.,” Anderegg says. “We’ve seen devastating fire seasons with increasing severity in the past several years. Generally, we expect the western U.S. to be hit hardest by all three of these. And they’re somewhat interconnected too. Really hot and dry years, driven by climate change, tend to drive lots of fires, climate-driven tree mortality and insect outbreaks. But we have an opportunity here too. Addressing climate change quickly can help keep our forests and landscapes healthy.”

The study is published in Ecology Letters and was supported by the National Science Foundation, U.S. Department of Agriculture, David and Lucille Packard Foundation and Microsoft’s AI for Earth.

After publication, find the full study here.

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JOURNAL

Ecology Letters

DOI

10.1111/ele.14018 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Future climate risks from stress, insects and fire across US forests

ARTICLE PUBLICATION DATE

12-May-2022