New study sheds light on the evolution of animals

Peer-Reviewed Publication

UNIVERSITY OF OXFORD

 

IMAGE: RECONSTRUCTION OF THE EDIACARAN SEAFLOOR FROM THE NAMA GROUP, NAMIBIA, SHOWING EARLY ANIMAL DIVERSITY. CREDIT: OXFORD UNIVERSITY MUSEUM OF NATURAL HISTORY / MIGHTY FOSSILS view more 

CREDIT: OXFORD UNIVERSITY MUSEUM OF NATURAL HISTORY / MIGHTY FOSSILS

Key points:

• Scientists have been mystified as to why animals are missing in much of the fossil record;
• Researchers have developed a new method to determine if animals really were absent during certain geological eras, or if they were present but too fragile to be preserved;
• The findings establish a new maximum point at which animals first evolved on Earth.

A study led by the University of Oxford has brought us one step closer to solving a mystery that has puzzled naturalists since Charles Darwin: when did animals first appear in the history of Earth? The results have been published today in the journal Trends in Ecology & Evolution.

Animals* first occur in the fossil record around 574 million years ago. Their arrival appears as a sudden ‘explosion’ in rocks from the Cambrian period (539 million years ago to 485 million years ago) and seems to counter the typically gradual pace of evolutionary change. Many scientists (including Darwin himself) believe that the first animals actually evolved long before the Cambrian period, but they cannot explain why they are missing from the fossil record.

The ‘molecular clock’ method, for instance, suggests that animals first evolved 800 million years ago, during the early part of the Neoproterozoic era (1,000 million years ago to 539 million years ago). This approach uses the rates at which genes accumulate mutations to determine the point in time when two or more living species last shared a common ancestor. But although rocks from the early Neoproterozoic contain fossil microorganisms, such as bacteria and protists, no animal fossils have been found.

This posed a dilemma for palaeontologists: does the molecular clock method overestimate the point at which animals first evolved? Or were animals present during the early Neoproterozoic, but too soft and fragile to be preserved?

To investigate this, a team of researchers led by Dr Ross Anderson from the University of Oxford’s Department of Earth Sciences have carried out the most thorough assessment to date of the preservation conditions that would be expected to capture the earliest animal fossils.

Lead author Dr Ross Anderson said: ‘The first animals presumably lacked mineral-based shells or skeletons, and would have required exceptional conditions to be fossilised. But certain Cambrian mudstone deposits demonstrate exceptional preservation, even of soft and fragile animal tissues. We reasoned that if these conditions, known as Burgess Shale-Type (BST) preservation, also occurred in Neoproterozoic rocks, then a lack of fossils would suggest a real absence of animals at that time.’

To investigate this, the research team used a range of analytical techniques on samples of Cambrian mudstone deposits from almost 20 sites, to compare those hosting BST fossils with those preserving only mineral-based remains (such as trilobites). These methods included energy dispersive X-ray spectroscopy and X-ray diffraction carried out at the University of Oxford’s Departments of Earth Sciences and Materials, besides infrared spectroscopy carried out at Diamond Light Source, the UK’s national synchrotron.

The analysis found that fossils with exceptional BST-type preservation were particularly enriched in an antibacterial clay called berthierine. Samples with a composition of at least 20% berthierine yielded BST fossils in around 90% of cases.

Microscale mineral mapping of BST fossils revealed that another antibacterial clay, called kaolinite, appeared to directly bind to decaying tissues at an early stage, forming a protective halo during fossilisation.

‘The presence of these clays was the main predictor of whether rocks would harbour BST fossils’ added Dr Anderson. ‘This suggests that the clay particles act as an antibacterial barrier that prevents bacteria and other microorganisms from breaking down organic materials.’

The researchers then applied these techniques to analyse samples from numerous fossil-rich Neoproterozoic mudstone deposits. The analysis revealed that most did not have the compositions necessary for BST preservation. However, three deposits in Nunavut (Canada), Siberia (Russia), and Svalbard (Norway) had almost identical compositions to BST-rocks from the Cambrian period. Nevertheless, none of the samples from these three deposits contained animal fossils, even though conditions were likely favourable for their preservation.

Dr Anderson added: ‘Similarities in the distribution of clays with fossils in these rare early Neoproterozoic samples and with exceptional Cambrian deposits suggest that, in both cases, clays were attached to decaying tissues, and that conditions conducive to BST preservation were available in both time periods. This provides the first “evidence for absence” and supports the view that animals had not evolved by the early Neoproterozoic era, contrary to some molecular clock estimates.’

According to the researchers, the study suggests a possible maximum age to the origin of animals of around 789 million years: the youngest estimated age of the Svalbard formation. The group now intend to search for progressively younger Neoproterozoic deposits with conditions for BST preservation. This will confirm the age of rocks in which animals are missing from the fossil record because they really were absent, rather than because conditions did not enable them to be fossilised. They also intend to perform laboratory experiments to investigate the mechanisms that underpin clay-organic interactions in BST preservation.

Dr Anderson added: ‘Mapping the compositions of these rocks at the microscale is allowing us to understand the nature of the exceptional fossil record in a way that we have never been able to do before. Ultimately, this could help determine how the fossil record may be biased towards preserving certain species and tissues, altering our perception of biodiversity across different geological eras.’

*‘Animals’ can be defined as multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals feed on organic matter, breathe oxygen, reproduce sexually, have specialized sense organs and a nervous system, and are able to respond rapidly to stimuli.

Dickinsonia, one of the oldest animal fossils from the Ediacara Biota, Ediacaran Rawnsley Quartzite Formation, Australia. 560–550 million years old. Credit: Lidya Tarhan

CREDIT

Lidya Tarhan

Image of one of the Tonian sites with BST preservation but no animal fossils from fieldwork. Svanbergfjellet Formation, De Geerbukta, Svalbard, Norway. Credit: Ross Anderson / University of Oxford

CREDIT

Credit: Ross Anderson / University of Oxford

Reconstruction of Charnia, a candidate for the first animal fossil from the Ediacaran Period as old as 574 million years ago. Credit: Oxford University Museum of Natural History / Mighty Fossils

CREDIT

Credit: Oxford University Museum of Natural History / Mighty Fossils

Notes for editors:

For interview requests and media enquiries, please contact Dr Ross Anderson: ross.anderson@earth.ox.ac.uk. A package of photographs and images for media use (including captions) is available at https://drive.google.com/drive/folders/1veGl8EGPdmoynExnfgsVNcY1Vhix19f5

The study ‘Fossilisation processes and our reading of animal antiquity’ will be published in Trends in Ecology & Evolution. On Tuesday 27 June at 16:00 BST/ 11:00 ET: https://doi.org/10.1016/j.tree.2023.05.014. To view a copy of the paper under embargo before this, please contact Dr Ross Anderson: ross.anderson@earth.ox.ac.uk.

About the University of Oxford

 Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the seventh year running, and ​number 2 in the QS World Rankings 2022. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.

Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.

Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 200 new companies since 1988. Over a third of these companies have been created in the past three years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.

---

JOURNAL

Trends in Ecology & Evolution

DOI

10.1016/j.tree.2023.05.014 

ARTICLE TITLE

Fossilisation processes and our reading of animal antiquity

ARTICLE PUBLICATION DATE

27-Jun-2023

Chemical imbalance in the forebrain discovered in people with obsessive-compulsive disorder

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

• Using a high-powered MRI scanner, scientists have discovered an imbalance between neurochemicals in parts of OCD patients’ brains key to decision-making and habit.

• Chemical imbalances were related to OCD symptom severity, as well as habitual tendencies in a decision-making task.

• A similar but less pronounced neurochemical imbalance was also detected in healthy individuals with milder compulsive tendencies.    

• Neuroscientists argue that the findings are a “major piece of the puzzle” in understanding OCD, and could open up new lines of treatment.

Scientists at the University of Cambridge have used powerful new brain imaging techniques to reveal a neurochemical imbalance within regions of the frontal lobes in patients with obsessive-compulsive disorder (OCD).

The study shows that the balance between glutamate and GABA – two major neurotransmitter chemicals – is “disrupted” in OCD patients in two frontal regions of the brain.

Researchers also found that people who do not have OCD but are prone to habitual and compulsive behaviour have increased glutamate levels in one of these brain regions.

Neuroscientists behind the study say the findings will open up new avenues for treating OCD, a psychiatric disorder that affects up to 3% of Western populations and can be deeply disabling.

Using magnetic resonance spectroscopy, the researchers measured levels of glutamate and GABA in regions of the cerebral cortex, the outermost and most highly developed part of the human brain.

Glutamate is an “excitatory” neurochemical: it facilitates electrical impulses that fire neurons to send information around brain networks. GABA is an “inhibitory” neurotransmitter that works in opposition to glutamate by dampening neural excitability, creating a balance.

OCD sufferers had higher levels of glutamate and lower levels of GABA in the anterior cingulate cortex, compared to people without OCD.

Additionally, the severity of OCD symptoms, along with the inclination towards habitual and compulsive behaviour, was related to higher glutamate levels in the supplementary motor region. This was found to be the case in OCD patients as well as in healthy participants with milder compulsive tendencies.

The anterior cingulate cortex and the supplementary motor area are both centrally involved in deciding the balance between our conscious goals and more automatic habits. The research suggests that “compulsions arise from a dysregulated brain system for controlling habits” say scientists.

The research is funded by the Wellcome Trust, and the latest findings are published today in the journal Nature Communications. 

“Understanding obsessive-compulsive disorder is a central question for psychiatry. We have now shown definitive changes in these key neurotransmitters in OCD sufferers,” said senior author Prof Trevor Robbins from Cambridge’s Department of Psychology. “Excess glutamate and reduced GABA is disrupting the neural circuitry in key regions of the OCD brain.”

“Our findings are a major piece of the puzzle for understanding the mechanisms behind OCD. The results suggest new strategies for medication in OCD based on available drugs that regulate glutamate. In particular, drugs that inhibit presynaptic glutamate receptors,” said Robbins. A presynaptic receptor is the part of a nerve cell that controls release of neurotransmitter chemicals.

Severe OCD is a mental health disorder that causes untold misery for some sufferers. It can lead to loss of work and relationships, and social isolation. “Symptoms of intrusive thoughts and repetitive rituals can confine patients to their homes for months on end,” said Robbins. In extreme cases, the lack of control and sense of hopelessness caused by OCD can result in thoughts of suicide .

Current treatments for OCD are limited. While people with milder symptoms can benefit from some anti-depressants, for those with severe symptoms there are few options – often extreme – such as deep-brain stimulation and even neurosurgery to remove the anterior cingulate cortex entirely.

“Some treatments already target glutamate imbalance in a roundabout way,” said Dr Marjan Biria, study lead author, who conducted the work in Robbins’ Cambridge lab. “Now we have the evidence for why certain approaches seem to have some beneficial effects.”

The Wolfson Brain Imaging Centre at Cambridge is home to one of only seven ultra-powerful 7-Tesla Magnetic Resonance Spectroscopy (MRS) scanners in the UK. For the latest study, researchers scanned 31 clinically-diagnosed OCD sufferers, and 30 healthy volunteers as a control group.

“Standard MRS scanners can be quite crude, not picking up the glutamate signal very accurately. The 7-Tesla machine allows us to separate the overlapping signals and measure glutamate and GABA more precisely,” said Biria.

In addition to scans, researchers conducted tests and questionnaires with all participants to gauge obsessive-compulsive and habitual tendencies. The test used a computer-based task to establish a link between an action and reward. The scientists then uncoupled this link and observed whether participants continued to respond as a measure of habit.

“We tested whether people were more prone to repeating the same responses, like a habit, or adapting their behaviour to better pursue goals,” said Robbins. “Compulsions and habits are not the same, but impaired regulation of habits can be the basis of compulsions and shift people away from their goal-directed behaviour."

“In the supplementary motor area, which is a likely controller of the habit system, even the more mildly repetitive behaviour of healthy volunteers was related to the glutamate-GABA ratio.”

However, only clinical OCD sufferers showed excess glutamate and reduced GABA in their anterior cingulate cortex.

The researchers say that raised glutamate levels may prove to be a “biomarker” for OCD. This could guide new therapies, including medication but also non-invasive use of magnetic stimulation through the scalp, an approach which is showing some promise for treatment of OCD.

---

JOURNAL

Nature Communications

DOI

10.1038/s41467-023-38695-z 

METHOD OF RESEARCH

Imaging analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Cortical glutamate and GABA are related to compulsive behaviour in individuals with obsessive compulsive disorder and healthy controls

ARTICLE PUBLICATION DATE

27-Jun-2023

Prevalence of iron deficiency, iron-deficiency anemia in females ages 12-21

JAMA

Peer-Reviewed Publication

JAMA NETWORK

About The Study: Among 12- to 21-year-old U.S. females between 2003 and 2020, iron deficiency affected almost 40% and iron deficiency anemia affected 6%, with variation by the ferritin or hemoglobin thresholds used. Menstruation was a risk factor for both, but more than one-quarter of premenarchal individuals had iron deficiency. 

Authors: Angela C. Weyand, M.D., of the University of Michigan Medical School in Ann Arbor, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jama.2023.8020)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

#  #  #

Embed this link to provide your readers free access to the full-text article 

 https://jamanetwork.com/journals/jama/fullarticle/10.1001/jama.2023.8020?guestAccessKey=5e01eda1-2b8b-47f8-9ff8-5126024bd77e&utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_content=tfl&utm_term=062723

---

JOURNAL

JAMA

Fondant: Where baking and thermodynamics mix

Automated kneading and microscopy yield new findings in how sugar crystals form in confectionery, showing promise for improved texture control and potential for healthier, low-calorie alternatives

Peer-Reviewed Publication

AMERICAN INSTITUTE OF PHYSICS

 

IMAGE: A TYPICAL CRYSTALLIZATION PROCESS DURING THE PREPARATION OF FONDANT, WITH SKETCHES OF THE CRYSTALS ON MICROSCOPIC SCALE. CREDIT: HANNAH M. HARTGE view more 

CREDIT: A TYPICAL CRYSTALLIZATION PROCESS DURING THE PREPARATION OF FONDANT, WITH SKETCHES OF THE CRYSTALS ON MICROSCOPIC SCALE. CREDIT: HANNAH M. HARTGE

WASHINGTON, June 27, 2023 – With their unique appearance, texture, and mouthfeel, fondants have intrigued bakers and physicists for years. They present an appetizing enigma in the world of confectionery, an intriguing combination of sugar, water, and heat that, when manipulated correctly, yields a delectably creamy product.

Researchers from the Max Planck Institute for Polymer Research and Technische Universität Berlin studied the kinetic and thermodynamic processes of sugar crystallization in the making of fondant. In Physics of Fluids, by AIP Publishing, they combined a controlled kneading machine with light microscopy to precisely observe the process of fondant creation and link it to theoretical physics models. This allowed the team to track how different preparation methods influence the final structure and texture of fondant.

Such work is poised to provide new ways to better predict and control fondant texture, mouthfeel, and flow process.

“Our works shows the interplay between crystallization speeds and process parameters. Thus, we can predict structure and function,” said author Hannah Hartge. “So far, food systems like fondants were rarely explored in scientific research, especially physics.”

Historically, it has been difficult to reproducibly research thicker sugar solutions because they crystalize under cooling and stirring. To address this challenge, the group required a method with more control than a standard kitchen.

To study fondant creation, the researchers used a laboratory kneader, which allowed them to observe how fondants are produced and how they crystallize under high-force stirring.

As the kneading progressed and more sugar was pulled out of solution into crystals, the torque of the kneader dropped, which indicates a smoother texture. With further kneading, however, the large sugar crystals began to break up, leading to a peak in torque and resulting in a thicker solution more characteristic of a fondant.

“It was surprising to see the sugar crystals in the solution grow first during the early stages of stirring, and then the biggest get smaller again due to the stirring,” said author Thomas Vilgis. “Finally, their sizes adjust themselves, which leads to this fine creamy texture of fondants, provided the concentration, temperatures, and stirring speed are chosen correctly.”

This peak in thickness was highly dependent on the temperature and stirring speed, mimicking a well-established model – called classical nucleation theory – for how dissolved particles glom onto each other.

In future work, Hartge and Vilgis hope to explore the behavior of fondants created with sugar alternatives, such as erythritol and isomalt, paving the way for healthier, low-calorie fondant options. They aspire to inspire more studies on food systems from a fundamental physics perspective.

###

The article “Crystallization in highly supersaturated, agitated sucrose solutions” is authored by Hannah Maria Hartge, Eckhard Flöter, and Thomas A. Vilgis. It will appear in Physics of Fluids on June 27, 2023 (DOI: 10.1063/5.0150227). After that date, it can be accessed at https://doi.org/10.1063/5.0150227.

ABOUT THE JOURNAL

Physics of Fluids is devoted to the publication of original theoretical, computational, and experimental contributions to the dynamics of gases, liquids, and complex fluids. See https://aip.scitation.org/journal/phf.

###

---

JOURNAL

Physics of Fluids

DOI

10.1063/5.0150227 

ARTICLE TITLE

Crystallization in highly supersaturated, agitated sucrose solutions

ARTICLE PUBLICATION DATE

27-Jun-2023

VIS+AI: integrating visualization with artificial intelligence for efficient data analysis

Peer-Reviewed Publication

HIGHER EDUCATION PRESS

 

IMAGE: THREE LEVELS OF INTEGRATION OF VIS AND AI IN DATA ANALYSIS view more 

CREDIT: HIGHER EDUCATION PRESS LIMITED COMPANY

Visualization and artificial intelligence (AI) are well-applied approaches to data analysis. In complex data analysis scenarios, like epidemic traceability and city planning, humans need to understand large-scale data and make decisions, which requires complementing the strengths of both visualization and AI. However, how can AI and visualization complement each other and be integrated into data analysis processes are still missing.

To solve the problems, a research team led by Prof. Wei Chen published their new research in Frontiers of Computer Science co-published by Higher Education Press and Springer Nature.

The team define three integration levels of visualization and AI. Visualization and AI are first used separately, which are data analysis approaches at level 0: independent process. As the technology matures, visualization and AI have been applied to assist each other. Related approaches are known as VIS4AI and AI4VIS, which correspond to level 1: one-way assistance. One-way assistance cannot support feedback. Approaches at level 1 have no chance to assess or optimize the effect of the provided assistance. To further improve data analysis approaches, the next level requires dual-way assistance, which is level 2: deep integration.

VIS+AI aims at barrier-free communication between human intelligence and artificial intelligence in the scenario of visual analysis. The framework of VIS+AI can completely open up the channel between AI and visualization, which further links human intelligence. As shown on the left of the framework, the knowledge generation model is inherited from the previous level to inject human intelligence. As shown on the right of the framework, the channel between AI and visualization consists of three iterative loops: an interaction loop, an execution loop, and an intelligence optimization loop. Through the three loops, AI can adapt to dynamic data analysis processes, and therefore be deeply involved into the data analysis processes guided by humans.

VIS+AI: Integrating Visualization with Artificial Intelligence for Efficient Data Analysis 

The processing flow of LDoS detection

CREDIT

HIGHER EDUCATION PRESS LIMITED COMPANY

Research Article, Published: 06 June 2023

Xumeng WANG, Ziliang WU, Wenqi HUANG, Yating WEI, Zhaosong HUANG, Mingliang XU, Wei CHEN. VIS+AI: integrating visualization with artificial intelligence for efficient data analysis. Front. Comput. Sci., 2023, 17(6): 176709, https://doi.org/10.1007/s11704-023-2691-y

 

About Frontiers of Computer Science (FCS)

FCS was launched in 2007. It is published bimonthly both online and in print by HEP and Springer. Prof. Zhi-Hua Zhou from Nanjing University serves as the Editor-in-Chief. It aims to provide a forum for the publication of peer-reviewed papers to promote rapid communication and exchange between computer scientists. FCS covers all major branches of computer science, including: architecture, software, artificial intelligence, theoretical computer science, networks and communication, information systems, multimedia and graphics, information security, interdisciplinary, etc. The readers may be interested in the special columns "Perspective" and "Excellent Young Scholars Forum".

FCS is indexed by SCI(E), EI, DBLP, Scopus, etc. The latest IF is 2.669. FCS solicits the following article types: Review, Research Article, Letter.

---

JOURNAL

Frontiers of Computer Science

DOI

10.1007/s11704-023-2691-y 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

VIS+AI: integrating visualization with artificial intelligence for efficient data analysis

 

Slow walking could be sign of dementia in older dogs

Peer-Reviewed Publication

NORTH CAROLINA STATE UNIVERSITY

Dogs who slow down physically also slow down mentally, according to a new study from North Carolina State University. Measuring gait speed in senior dogs could be a simple way to monitor their health and to document decline in their neurological function as they age.

“Walking speed in people is strongly associated with cognitive decline,” says Natasha Olby, Dr. Kady M. Gjessing and Rahna M. Davidson Distinguished Chair in Gerontology at NC State and corresponding author of the study. “We hypothesized that the same might be true in dogs.”

Olby and her colleagues measured gait speed off leash in 46 adult and 49 senior dogs. The adult dogs, who served as a control group, only had their gait speed measured. The senior dogs did some additional cognitive testing and their owners filled out a cognitive assessment questionnaire, called the CADES questionnaire. A higher CADES score indicates more severe cognitive decline.

The senior dogs were grouped together based on their CADES and cognitive testing scores. Individual gait speed was measured first by walking them over a five meter distance on a leash with a handler, then by offering a treat the same distance away from the dogs, and calling them to retrieve it off leash.

“The challenge with measuring gait speed is that dogs tend to match the speed of their handler when on leash, so we measured both on and off leash to see which was the most useful measure,” Olby says.

“Additionally, we are always concerned that body size and limb length will affect gait speed – but if you see a chihuahua and a great dane walking together off leash, the shorter one isn’t always behind the other,” Olby continues. “We found that on leash, size does correlate with gait speed, but off leash it doesn’t make a difference. Capturing gait speed off leash lets us see the effects of both physical ability and food motivation.”

The researchers found that in the senior dogs, size didn’t matter when it came to speed; in other words, dogs in the last 25% of their expected life span moved more slowly than adult dogs, regardless of relative size.

“Just as in humans, our walking speed is pretty stable through most of our lives, then it declines as we enter the last quarter or so of our lifespan,” Olby says.

Senior dogs who moved more slowly had more severe levels of cognitive decline based on the owner-completed questionnaires and also did worse on the cognitive testing.

The researchers also found that joint pain did not seem to correlate with walking speed, although they note that there were no dogs with severe osteoarthritis in the program. They hope to address this issue in future work.

“When you look at functional aging, the two most important predictors of morbidity are mobility and cognition,” Olby says. “Mobility relies heavily on sensory input, central processing and motor output – in other words, the nervous system – as a result, mobility and cognition are super interconnected. When you have less mobility, the amount of input your nervous system gets is also reduced. It’s not surprising that walking speed and dementia are correlated.

“For me, the exciting part of the study is not only that we show gait speed correlates with dementia in dogs as in people, but also that the method of testing we used is easy to replicate, since it’s food motivated and over a short distance. It could become a simple screening test for any veterinarian to perform on aging patients.”

The work appears in Frontiers in Veterinary Science and was supported by the Kady M. Gjessing and Rahna M. Davidson Distinguished Chair in Gerontology. Alejandra Mondino, postdoctoral researcher at NC State, is lead author of the study.

-peake-

Note to editors: An abstract follows.

“Winning the race with aging: age-related changes in gait speed and its association with cognitive performance in dogs.”

DOI: 10.3389/fvets.2023.1150590

Authors: Alejandra Mondino, Michael Khan, Beth Case, Gilad Fefer, Wojciech K. Panek, Margaret E. Gruen and Natasha J. Olby, North Carolina State University
Published: June 15, 2023 in Frontiers in Veterinary Science

Abstract:
In humans, gait speed is a crucial component in geriatric evaluation since decreasing speed can be a harbinger of cognitive decline and dementia. Aging companion dogs can suffer from age-related mobility impairment, cognitive decline and dementia known as canine cognitive dysfunction syndrome. We hypothesized that there would be an association between gait speed and cognition in aging dogs. We measured gait speed on and off leash in 46 adult and 49 senior dogs. Cognitive performance in senior dogs was assessed by means of the Canine Dementia Scale and a battery of cognitive tests. We demonstrated that dogs’ gait speed off leash, a relatively easy variable to measure in clinical settings, is correlated with fractional lifespan and cognitive performance in dogs, particularly in the domains of attention and working memory. Moreover, food-motivated gait speed off leash proves to be a more effective indicator of age-related deterioration and cognitive decline than gait speed on leash.

---

JOURNAL

Frontiers in Veterinary Science

DOI

10.3389/fvets.2023.1150590 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Winning the race with aging: age-related changes in gait speed and its association with cognitive performance in dogs

 

Hot testicles may hold the secret to elephants’ anti-cancer genes, suggests new study

Peer-Reviewed Publication

SAVE THE ELEPHANTS

A ground-breaking study published today in the prestigious journal, Trends in Ecology & Evolution, unveils an intriguing connection between hot testicles and the evolution of potent anti-cancer genes in elephants.

Led by Professor Fritz Vollrath, Chairman of Save the Elephants, the research suggests that the absence of testicular descent in elephants may have driven the development of multiple anti-cancer genes, safeguarding their temperature-sensitive sperm production.

This novel hypothesis presents an exciting avenue for cancer researchers, potentially offering valuable insights into understanding the cellular response to DNA damage in humans.

Despite their large size and a higher number of somatic cell divisions, which traditionally increase cancer risk, elephants defy conventional expectations. This phenomenon, known as Peto’s Paradox, was first observed by renowned Oxford epidemiologist Richard Peto, who noted that elephants and whales appear to be surprisingly resistant to the development of cancers.

Recent scientific advancements have shed light on the importance of elephants in deciphering this intriguing cancer mitigation puzzle. Key is the link between a genetic marker, the TP53 gene, and its protein product p53.  P53 identifies and neutralizes damaged DNA during cell divisions and thus impedes the spread of mutations.

Remarkably, elephants stand out by hosting 20 copies of the TP53 gene, while all other known animals, including humans, possess only a single copy. This begs the question: why have elephants evolved this seemingly magical defence mechanism against cancer when other species have not?

The study published in Trends in Ecology & Evolution highlights that selection on somatic cells, which make up bodies, organs and tissues, is relatively weak and slow due to the intricate mix of healthy and potentially harmful cells. Additionally, evolution tends to proceed gradually when limited to developments occurring in older age, after most offspring have been produced. In contrast, selection on germ cells, such as sperm and eggs, is considerably stronger and faster, as it directly impacts the survival of each individual cell.

This brings us to the intriguing topic of testicle temperature. In mammals, the production of healthy sperm relies on the testes being several degrees cooler than the body temperature. Consequently, the descent of testicles into a scrotum plays a vital role in cooling them as maturity approaches. Elephants, however, lack the genes responsible for this descent, resulting in their testicles remaining inside their bodies even in mature bulls, subjecting them to elevated temperatures.

Considering elephants’ inherent vulnerability to climatic challenges due to their bulk, unfavourable surface ratio, thick skin, and heat exchange mechanisms centred on blood flow in the ear flaps, their body temperatures can soar to levels that are detrimental to mammalian metabolism and detrimental to healthy sperm production.

Under the paradigm presented by this study, the proliferation of TP53 genes would not have primarily evolved to combat cancer but rather to support DNA stabilization in the spermatogonia, ensuring the production of robust spermatozoa and safeguarding the germ line. Nevertheless, this diversification of p53 proteins also offers protective benefits against DNA damage and mutations in somatic cell lines, thus providing additional collateral advantages linked to cancer and aging, an area where p53 is well known to play a prominent role.

Professor Fritz Vollrath, commenting on the research, says, “Elephants provide us with a unique system to study the evolution of a robust defence mechanism against DNA damage and explore the intricate details of the p53 complex in our own battle against cancer and ailments like aging. Novel insights in this field are always important, but especially now that overheating is becoming ever more of an issue also for us humans.”

Read the full study in Trends in Ecology & Evolution 

 ENDS

---

For further information and images, please contact:

Professor Fritz Vollrath
Oxford, UK
fritz.vollrath@biology.ox.ac.uk

OR

Jane Wynyard
Save the Elephants, Kenya
jane@savetheelephants.org

About Save the Elephants

Save the Elephants works to secure a future for elephants. Specialising in elephant research, they provide scientific insights into elephant behaviour, intelligence, and long-distance movements and apply them to the challenges of elephant survival and harmonious coexistence with humanity. High-tech tracking helps plan landscapes while low-tech beehive fences, among other tools, provide people /communities living with elephants with protection as well as income.  Education and outreach programmes share these insights with local communities as the true custodians of this rich heritage.  Save the Elephants runs the Elephant Crisis Fund in partnership with the Wildlife Conservation Network, providing flexible and responsive support to NGOs combatting the ivory trade, promoting human-elephant coexistence, and protecting elephant landscapes. www.savetheelephants.org

---

JOURNAL

Trends in Ecology & Evolution

ARTICLE TITLE

Uncoupling elephant TP53 and cancer

ARTICLE PUBLICATION DATE

27-Jun-2023