21ST CENTURY ALCHEMY

Stanford researchers unveil new material infused with gold in an exotic chemical state

Peer-Reviewed Publication

STANFORD UNIVERSITY

For the first time, Stanford researchers have found a way to create and stabilize an extremely rare form of gold that has lost two negatively charged electrons, denoted Au2+. The material stabilizing this elusive version of the valued element is a halide perovskite—a class of crystalline materials that holds great promise for various applications including more-efficient solar cells, light sources, and electronics components.

Surprisingly, the Au2+ perovskite is also quick and simple to make using off-the-shelf ingredients at room temperature.

"It was a real surprise that we were able to synthesize a stable material containing Au2+—I didn't even believe it at first," said Hemamala Karunadasa, associate professor of chemistry at the Stanford School of Humanities and Sciences and senior author of the study published Aug. 28 in Nature Chemistry. "Creating this first-of-its-kind Au2+ perovskite is exciting. The gold atoms in the perovskite bear strong similarities to the copper atoms in high-temperature superconductors, and heavy atoms with unpaired electrons, like Au2+, show cool magnetic effects not seen in lighter atoms."

"Halide perovskites possess really attractive properties for many everyday applications, so we've been looking to expand this family of materials," said Kurt Lindquist, the lead author of the study who conducted the research as a Stanford doctoral student and is now a postdoctoral scholar in inorganic chemistry at Princeton University. "An unprecedented Au2+ perovskite could open some intriguing new avenues."

Heavy electrons in gold

As an elemental metal, gold has long been valued for its relative scarcity as well as its unmatched malleability and chemical inertness—meaning it can be easily shaped into jewelry and coins that do not react with chemicals in the environment and tarnish over time. An additional key reason for its value is gold's namesake color; arguably no other metal in its pure state has such a distinctively rich hue.

The fundamental physics behind gold's acclaimed appearance also explains why Au2+ is so rare, Karunadasa explained. 

The root reason is relativistic effects, originally postulated in Albert Einstein's famed theory of relativity. "Einstein taught us that when objects move very fast and their velocity approaches a significant fraction of the speed of light, the objects get heavier,” Karunadasa said.

This phenomenon applies to particles, too, and has profound consequences for “massive” heavy elements, such as gold, whose atomic nuclei boast a large number of protons. These particles collectively exert immense positive charge, forcing negatively charged electrons to whirl around the nucleus at breakneck speeds. As a consequence, the electrons grow heavy and tightly surround the nucleus, blunting its charge and allowing outer electrons to drift farther than in typical metals. This rearrangement of electrons and their energy levels leads to gold absorbing blue light and therefore appearing yellow to our eye.

Because of the arrangement of gold's electrons, thanks to relativity, the atom naturally occurs as Au1+ and Au3+, losing one or three electrons, respectively, and spurning Au2+. (The “2+” indicates a net positive charge from the loss of two negatively charged electrons, and the "Au" chemical symbol for gold hails from “aurum,” the Latin word for gold.)

A squeeze of vitamin C

With just the right molecular configuration, Au2+ can endure, the Stanford researchers found. Lindquist said he "stumbled upon" the new Au2+-harboring perovskite while working on a broader project centered on magnetic semiconductors for use in electronic devices.

Lindquist mixed a salt called cesium chloride and Au3+-chloride together in water and added hydrochloric acid to the solution "with a little vitamin C thrown in," he said. In the ensuing reaction, vitamin C (an acid) donates a (negatively charged) electron to the common Au3+ forming Au2+. Intriguingly, Au2+ is stable in the solid perovskite but not in solution.

"In the lab, we can make this material using very simple ingredients in about five minutes at room temperature," said Lindquist. "We end up with a powder that's very dark green, nearly black, and is surprisingly heavy because of the gold it contains."

Recognizing that they may have hit new chemistry paydirt, so to speak, Lindquist performed numerous tests on the perovskite, including spectroscopy and X-ray diffraction, to investigate how it absorbs light and to characterize its crystal structure. Stanford research groups in physics and chemistry led by Young Lee, professor of applied physics and of photon science, and Edward Solomon, the Monroe E. Spaght Professor of Chemistry and professor of photon science, further contributed to studying the behavior of Au2+.

The experiments ultimately bore out the presence of Au2+ in a perovskite and, in the process, added a chapter to a century-old story of chemistry and physics involving Linus Pauling, who received the Nobel Prize in Chemistry in 1954 and the Nobel Peace Prize in 1962. Early in his career, he worked on gold perovskites containing the common forms Au1+ and Au3+. Coincidentally, Pauling also later studied the structure of vitamin C—one of the ingredients required to yield a stable perovskite containing the elusive Au2+.

"We love Linus Pauling’s connection to our work," Karunadasa said. "The synthesis of this perovskite makes for a good story."

Looking ahead, Karunadasa, Lindquist, and colleagues plan to study the new material further and tweak its chemistry. The hope is that an Au2+ perovskite can be used in applications that require magnetism and conductivity as electrons hop from Au2+ to Au3+ in the perovskite.

"We're excited to explore what an Au2+ perovskite could do," Karunadasa said.

Karunadasa is also a senior fellow at the Precourt Institute for Energy and a principal investigator and faculty scientist at the Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory. Solomon is a professor of photon science at Stanford Synchrotron Radiation Lightsource, SLAC. Additional Stanford co-authors are Christina R. Deschene and Alexander J. Heyer, graduate students in the Department of Chemistry; and Jiajia Wen, a staff scientist at SLAC. Additional co-authors include Armin Eghdami and Alexander G. Smith, graduate students in the Department of Physics, University of California-Berkeley, and Jeffrey B. Neaton, professor of physics at the University of California-Berkeley; and Dominic H. Ryan, professor of physics at McGill University.

The research was funded in part by the U.S. National Science Foundation, the U.S. Department of Energy, the Fonds de recherche du Québec–Nature et technologies, and the Natural Sciences and Engineering Research Council Canada.

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JOURNAL

Nature Chemistry

DOI

10.1038/s41557-023-01305-y 

ARTICLE TITLE

Stabilizing Au2+ in a mixed-valence 3D halide perovskite

 

Study pinpoints the length of incidental activity linked to health benefits

Peer-Reviewed Publication

UNIVERSITY OF SYDNEY

A new wearables study tracking over 25,000 people provides the best evidence yet that short bouts of incidental activity, the kind we do as part of daily living, could reduce risk of heart attack, stroke and even premature death – but the length of activity and intensity matters.

“From walking up the stairs to speedily mopping the floors; in recent years we’ve come to understand that it is not just structured exercise that is good for our health, but we know very little about how these short bouts of incidental activity translate to health benefits,” said the study’s senior author Professor Emmanuel Stamatakis from the University of Sydney’s Charles Perkins Centre.

In a study published in The Lancet Public Health today, a University of Sydney led team of international researchers with collaborators from University College London, University of Glasgow, University of Edinburgh, Loughborough University and University of Oxford set out to answer that question.

They used wrist-worn wearables data from the UK Biobank and machine learning to analyse the seven-day incidental physical activity patterns of 25, 241 UK adults aged 42 to 78, down to a 10-second time window. They then linked these physical activity micropatterns with participants' health records, following them for close to eight years to identify how length and intensity of physical activity bouts were linked to health status.

In this cohort of people who self-reported no participation in exercise or sport they found;

• 97% of incidental physical activity was accrued in bouts lasting <10 minutes
• Short bouts of <10 minutes at a moderate to vigorous intensity were associated with a steep decrease in major cardiac events (heart attack/stroke) and death by any cause.
• Moving consistently for at least 1 to 3 minutes was associated with significantly more benefit (29% lower) than very short bouts <1 minute.
• The longer the bouts the better (e.g., accrued in 2 minutes vs 30 seconds), regardless of total activity levels.
• The higher the % of vigorous activity in each bout the better – those who huffed and puffed for at least 15% of the bout (roughly 10 seconds per minute) saw the greatest benefit.
• Bouts <1 minute were also associated with benefits if the above 15% vigorous activity rule was applied.

 

“This study suggests people could potentially reduce their risk of major cardiac events by engaging in daily living activities of at least moderate intensity where they are ideally moving continuously for at least one to three minutes at a time. In fact, it appears that this can have comparable health benefits to longer bouts lasting 5 to 10 minutes,” said lead author Dr Matthew Ahmadi, Postdoctoral Research Fellow at the University of Sydney’s Charles Perkins Centre.

“The take-home message here is any type of activity is good for your health, but the more effort you put into those daily tasks and the longer you keep up that energy, the more benefits you are likely to reap,” said Professor Stamatakis.

“If you are huffing and puffing and unable to hold a conversation for some of that time you have hit the sweet spot.”

The observational nature of the study means researchers cannot prove a cause-and-effect relationship with certainty. However, the researchers made extensive use of the UK Biobank’s baseline health information allowing them to account for a number of factors such as diet, smoking, alcohol consumption, sleep and sedentary time. They also took precautionary measures against the potential effects of reverse causation, whereby poor health may influence activity patterns, by excluding those who had a cardiac event within five years of the wearables measurement, high frailty, and poor self-rated health.

Why do we need to know more about incidental activity?

Fewer than one in five middle-aged adults engage in regular exercise. There are a number of reasons for this including cost, time commitment, health status and access to facilities or infrastructure, but the fact remains that most people are not meeting recommended physical activity guidelines.

“The idea of accruing short bouts of moderate to vigorous activity through daily living activities makes physical activity much more accessible to people who are unwilling or unable to take part in structured exercise,” said Dr Ahmadi. “But as we see in this data, the length and the vigour people put into these incidental activities matters.”

The researchers say the study also provides some of the first direct evidence to support the idea that movement doesn’t have to be completed in continuous 10 minute bouts to be beneficial – a widely held belief until the World Health Organization removed this from their physical activity guidelines in 2020, instead focusing on the idea that ‘every move counts towards better health’. 

The researchers write: “If verified in future research, our findings could inform future public health messaging targeting the general population raising awareness of potential health benefits from short physical activity bouts in everyday life, especially for adults who do not or cannot exercise.”

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JOURNAL

The Lancet Public Health

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Brief bouts of device-measured intermittent lifestyle physical activity and its association with major adverse cardiovascular events and mortality in people who do not exercise: a prospective cohort study

ARTICLE PUBLICATION DATE

28-Sep-2023

COI STATEMENT

The authors have no competing interests to declare. The study was funded by an Australian National Health and Medical Research Council Grant and an Ideas Grant. Prof Doherty is supported by the Wellcome Trust. The research was conducted using the UK Biobank Resource.

 

Alcohol 'promotion' detracted from success of Women's World Cup

Peer-Reviewed Publication

SAGE

Broadcasters should avoid focusing on alcohol in crowd shots during major sporting events, such as this summer’s Women’s World Cup final, say researchers.

In a new commentary published in the Journal of the Royal Society of Medicine (JRSM), researchers from the Technological University of the Shannon and the University of Galway in the Republic of Ireland suggest that the ‘thorny issue of alcohol’ detracted from the success of the record-breaking tournament.

The authors, Dr Frank Houghton and Daisy Houghton, highlight a ‘highly problematic’ moment during the final between England and Spain, which was broadcast to tens of millions worldwide. Around 30 minutes into the match, the camera focused on a fan celebrating Spain’s winning goal while holding a cup of beer.

Such coverage “highlights, normalises and glamourises alcohol consumption, as well as showing positives rather than negative consequences,” say the authors. “It also has connotations such as: fans drink alcohol, fans drink while watching sport and drinking alcohol can make you the centre of attention. One aspect of particular concern is the substantial youth audience that were undoubtedly watching this Cup Final match, particularly young girls.”

They argue that the health impacts of alcohol consumption warrant tighter regulation of broadcasters. They say: “Alcohol is an important negative commercial determinant of health for both men and women, with alcohol noted as a significant predictor of breast cancer in women in particular.

“The UK and Ireland have an established problem with alcohol and as such this form of de facto alcohol promotion is highly problematic.”

They call for an alcohol-oriented equivalent of the Framework Convention on Tobacco Control, which they say has been a ‘significant factor’ in controlling tobacco promotion.

However, even this would not be enough; media coverage, because it is not paid advertising, would “fall through the cracks of such international agreements,” they add. “However, an undertaking to avoid a focus on alcohol in crowd shots could easily be included in contractual agreements between broadcasters and those agencies filming sports events and would quickly solve this issue, particularly if financial penalties for non-adherence were included. The implementation of such a contractual rule in negotiations for State-funded television channels should be relatively easy, although more extended work by Public Health advocates may be required with for-profit broadcasters.”

ENDS

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JOURNAL

Journal of the Royal Society of Medicine

DOI

10.1177/01410768231202656 

ARTICLE TITLE

The Women’s Soccer World Cup Final 2023: gender equity and alcohol promotion

ARTICLE PUBLICATION DATE

29-Sep-2023

 

Solving a sticky, life-threatening problem

Candida auris is an emerging fungal threat—and its unique way of sticking to surfaces may underlie its virulence

Peer-Reviewed Publication

MICHIGAN MEDICINE - UNIVERSITY OF MICHIGAN

In 2009, a mysterious fungus emerged seemingly from out of thin air, targeting the most vulnerable among us. It sounds like Hollywood, but the fungus in question poses a very real threat. Scientists are scrambling to figure out what makes the life-threatening fungus Candida auris tick--and why even the best infection control protocols in hospitals and other care settings often fail to get rid of it.

Researchers at U-M have zeroed in on C. auris’ uncanny ability to stick to everything from skin to catheters and made a startling discovery.

The investigative team, led by Teresa O’Meara, Ph.D. of the U-M Medical School Department of Microbiology and Immunology and her graduate student Darian Santana, has discovered that C. auris is unlike any other known fungus in that it employs a type of protein, called an adhesin, that acts very similar to those used by oceanic organisms, such as barnacles and mollusks.

Their original hypothesis was that C. auris would use an adhesin from the families of sticky proteins used by other fungi like C. albicans. However, when they checked the usual suspects, namely proteins from the highly conserved ALS and IFF/HYR families, they came up mostly short, except for one protein, IFF4109, with a partial affect.

They then pivoted to a different screening method to systematically break the genome of C. auris and see which mutant lost its ability to stick to 96-well plastic plates—leading to the discovery of a new adhesin they named Surface Colonization Factor (SCF1).

“The new adhesin is only present in C. auris so we don’t know where it came from evolutionarily. It doesn’t look like it came from any other organisms by sequence similarity,” said O’Meara. The bonds formed by Scf1, they revealed, are cation-pi bonds, which are among the strongest non-covalent chemical bonds in nature.

Said O’Meara, “Much of the literature about this type of bond in nature comes from people trying to bioengineer glue that adheres underwater. Hence, they’ve looked to nature for inspiration.”

Furthermore, the team discovered that SCF1 was associated with increased colonization and an enhanced ability to cause disease. Using mouse models, they demonstrated that a loss of both SCF1 and IFF4109 diminished the ability of a strain of C. auris to colonize skin and an in-dwelling catheter. What’s more, strains designed to over express SCF1 saw enhanced virulence and more fungal lesions.

“We don’t know why this adhesin is required to cause disease,” said O’Meara. “It could be that they’re required to attached to blood vessels, or maybe they change the host-receptor interactions which has been true for the related fungus Candida albicans, but we don’t know in this case.”

O’Meara and her team plan to investigate the link between SCF1 and virulence in the hopes of exploiting it for a more effective anti-fungal therapy, as many strains of C. auris are resistant to current medications. The adhesin may also provide a clue about where C. auris came from, said O’Meara, with its barnacle-like adhesive properties suggesting an oceanic origin.

“Unlike SARS-CoV2, which emerged in one place, C. auris suddenly appeared in 5 distinct locations around the world. There’s some selective pressure in the world that changed that allowed C. auris to go from not a threat at all to colonizing people.”

Additional authors include Darian J. Santana, Juliet A. E. Anku, Guolei Zhao, Robert Zarnowski, Chad J. Johnson, Haley Hautau, Noelle D. Visser, Ashraf S. Ibrahim, David Andes , Jeniel E. Nett , and Shakti Singh

Paper cited: “A Candida auris-specific adhesin, SCF1, governs surface association, colonization, and virulence,” Science.

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JOURNAL

Science

DOI

10.1126/science.adf8972 

ARTICLE TITLE

A Candida auris-specific adhesin, SCF1, governs surface association, colonization, and virulence

ARTICLE PUBLICATION DATE

29-Sep-2023

 

New insights into how the human brain organises language

Leipzig scientists publish largest meta-analysis on language processing to date

Peer-Reviewed Publication

UNIVERSITÄT LEIPZIG

Language is the most important tool for human communication and essential for life in our society. “Despite a great deal of neuroscientific research on the representation of language, little is known about the organisation of language in the human brain. Much of what we do know comes from single studies with small numbers of subjects and has not been confirmed in follow-up studies,” says Dr Sabrina Turker from the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig. This meta-analysis aims to help change that.

Based on more than 400 neuroscientific experiments using functional imaging and involving more than 7000 subjects, the analysis provides in-depth insights into how the brain organises language. A quantitative, coordinate-based meta-analysis was used to integrate the many findings from different studies in the most complete and objective way possible. This makes it possible to see where the brain is activated when particular language processes occur. This approach provides insights into fundamental principles of how the brain organises language processing. The researchers not only studied language as a process in general, but also explicitly addressed subordinate processes: the meaning of language at the level of words and sentences (semantics); the phonetic structure of language (phonology); grammar and the arrangement of linguistic elements (syntax); and the phonetic structure of language at sentence level, including melody, intonation and rhythm (prosody).

In addition to the classical language regions in the left hemisphere of the brain, the authors of the study found that structures in the brain regions below the cerebral cortex and the cerebellum play a key role in language processes.

“These regions have been rather neglected in previous neuroscientific research on language,” says Gesa Hartwigsen, Professor of Cognitive and Biological Psychology at Leipzig University. “In particular, the left and right cerebellum are involved in processes related to the meaning of language and the processing of sounds. Similarly, phonetic patterns that transcend individual words and also convey emotional meaning are associated with activation in the right amygdala, a paired core area of the brain.” She points out that this part influences emotion and memory.

Professor Gesa Hartwigsen adds: “Our findings may serve future studies involving language recovery after brain injury, for example caused by stroke. And they could help to refine models of language processing.”

https://youtu.be/h2B406WiyKQ

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JOURNAL

Psychological Bulletin

DOI

10.1037/bul0000403 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Cortical, Subcortical, and Cerebellar Contributions to Language Processing: A Meta-Analytic Review of 403 Neuroimaging Experiments

ARTICLE PUBLICATION DATE

28-Sep-2023

 

Insights into early snake evolution through brain analysis

Peer-Reviewed Publication

UNIVERSITY OF HELSINKI

 

IMAGE: 

LIFESTYLE AND BRAIN RECONSTRUCTIONS OF THE HYPOTHETICAL ANCESTOR OF MODERN SNAKES.

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CREDIT: SIMONE MACRÌ AND NICOLAS DI-POÏ.

Recent study sheds new light on the enigmatic early evolution of snakes by examining an unexpected source: their brains. The results emphasise the significance of studying both the soft parts of animals’ bodies and their bones for understanding how animals evolved.

Snakes are fascinating creatures, forming about one-eighth of vertebrate animals found on land. They come in a wide range of forms and sizes and have adjusted to different ways of life, such as living underground, on the land, in water, and up in trees. However, the early evolution of snakes and the changes in their morphologies over time has been long debated in the field of biology.

To help unravel this mystery, researchers from the HiLIFE Institute of Biotechnology, University of Helsinki used a different way of studying snake evolution.

“Instead of relying on rare, old fossil remains to learn about the history of snakes, we looked at the brains of living reptiles and traveled back in time, thanks to modern imaging and analysis tools” says the first author of the study, Postdoctoral Researcher Simone Macrì.

By using high-definition 3D models of modern lizard and snake brains, researchers reconstructed the brain shape of early snakes and discovered that they were fully adapted for underground living. Nevertheless, early snakes also displayed versatile behaviors, as evidenced by the mixture of different features and complex patterns in their brain morphologies, which may reflect differences in what they eat, how they use different environments both below and above the ground, and their ability to search for food.

Understanding animal evolution beyond fossils

“What's really exciting is that this study is not only about snakes! It's also showing us a way to learn about other animals whose history is a bit of a mystery because we lack fossils for studying them”, describes Principal Investigator Nicolas Di-Poï, Research Director at the Institute of Biotechnology, University of Helsinki.

By examining both present-day animals and those from the past, along with bones and different crucial organs like the brain, scientists can piece together the story of how these creatures changed and evolved over time.

This research underscores a vital lesson for the field of biology: unraveling the mysteries of animal evolution goes beyond the analysis of bone remains. To comprehend the transformation of creatures like snakes over time, scientists must consider other components of their bodies, including soft tissues and internal organs. This is particularly crucial when studying animals from eras when their bones might not have been well-preserved.

 

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JOURNAL

Science Advances

DOI

10.1126/sciadv.adi6888 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Reconstructing the origin and early evolution of the snake brain

ARTICLE PUBLICATION DATE

27-Sep-2023

 

Explosion in fish biodiversity due to genetic recycling

The rapid formation of 500 different species of fish in a single lake, each with specialised ecological roles, resulted from a small but genetically diverse hybrid population.

Peer-Reviewed Publication

WELLCOME TRUST SANGER INSTITUTE

Scientists show the extraordinary diversity of cichlid fish in Africa’s Lake Victoria was made possible by ‘genetic recycling’ - repeated cycles of new species appearing and rapidly adapting to different roles in the ecosystem. In an evolutionary case study that has fascinated researchers for decades, the research sheds light on how 500 species of fish were able to emerge and thrive in just 16,000 years.

By comparing genomes of hundreds of present-day cichlid fish species, researchers from a multinational team, led by Joana Meier and Ole Seehausen from the Swiss water research institute Eawag, the University of Bern, the University of Cambridge and the Wellcome Sanger Institute, showed that hybridisation – where two different species come together and merge their genes to create a new species with a mix of characteristics from both parent types – enabled cichlids to do so well. The research team also identified unique ancient genes that spurred on this process.

The findings, published today (28 September) in Science, reveal the reasons behind cichlids’ unique ecological diversity. They also provide important insights into the genetic basis of adaptive evolution and diversification.

Cichlids in Lake Victoria have adapted to occupy nearly every imaginable role in the ecosystem. They come in various sizes, shapes, colours, ranging from top predators down to tiny zooplankton. These cichlids are considered a classic example of ‘adaptive radiation,’ where one group gives rise to many species, each with unique characteristics and behaviours. It was unclear whether this diversification occurred solely within Lake Victoria, an astonishingly rapid process of around 16,000 years, following a 4,000-year dry period. This pace far exceeds that of Darwin's finches, which took millions of years to evolve 14 species.

In this new study, the research team set out to investigate if these cichlids indeed evolved extremely rapidly within the lake, and if so, how they were able to do so. As part of this, they tested whether Lake Victoria cichlids really are distinct species1 and the genetic factors that underpinned this unprecedented scale of evolution.

The team analysed 464 whole genomes of modern cichlids from Lake Victoria and the wider Great African Lakes region. The findings confirmed cichlids found in the lake are indeed separate species evolved from the same mix of genes, having evolved within Lake Victoria after the dry period through a common hybridisation event. Their evolutionary history is marked by repeated "genetic recycling" – periods where different groups of fish mated and mixed their genes followed by them eventually separating into new species.

Researchers determined that around 16,000 years ago, when the lake refilled, three swamp-dwelling cichlid populations came together, merging their genes to give rise to hybrid fish. The initial genetic diversity in these three cichlid populations2 played a crucial role in their potential to evolve ecological groups. Each swamp population contributed different gene variants, such as genes for hunting or algae scraping.

By mixing their genes, they generated a large amount of genetic diversity, a faster mechanism than waiting for new mutations to accumulate slowly. The hybrids developed different behaviours, each occupying distinct ecological roles like hunting, algae-scraping, zooplankton sifting and insect eating, while mostly breeding within their groups. This led to the rapid formation of various species.

Despite these adaptive differences, their close genetic relationship allowed for episodes of ongoing hybridisation, creating even more genetic combinations. For instance, the combination of genes from large predators and small zooplanktivores gave rise to a new ecological group of dwarf predators, combining the predatory lifestyle with the small body size of zooplanktivores.

Professor Ole Seehausen, senior author of the study, Professor of the University of Bern and the Swiss water research Institute EAWAG, said: “Thanks to cycles of hybridisation and diversification, countless variations in inherited traits have been preserved that have accumulated in these cichlid populations for millions of years. Species today hold in their genomes the potential for rapid “reconstruction” of incredibly advantageous specialisations. Our findings emphasise the importance, in conservation biology, of considering the connections between species, both genetically and ecologically, rather than viewing them in isolation. By preserving diverse species, we retain a resource pool that can help them adapt to environmental changes, such as coping with rising temperatures through ocassional hybridisation and sharing adaptations.”

Dr Joana Meier, first author of the study and group leader at the Wellcome Sanger Institute, said: “Hybridisation might be more prevalent – and important – in nature than we previously thought. Genomics can reveal these secrets. As we explore reasons behind the remarkable success of these fish and in my ongoing work across the tree of life, we are glimpsing the very cogs and wheels of evolution — insights that may help researchers decode the origins of all manner of species.”

ENDS

Notes to Editors: 

1. Previous attempts using mitochondrial analysis were inconclusive in determining the species status of Lake Victoria cichlids. This uncertainty arose from their relatively recent divergence, occurring only 16,000 years ago, which resulted in limited genetic differences in mitochondrial DNA and a lack of robust statistical support. Genomic approaches, in contrast, examine the full spectrum of genes and DNA sequences, offering a broader array of genetic markers and variations for researchers to assess, providing a more accurate and comprehensive understanding of the cichlids' genetic relationships.

2. The study also suggests that the three founding lineages themselves are hybrids from an older hybridisation event 350,000 years ago.

The authors dedicate the paper to colleague, collaborator, and friend, Sylvester Bwaku Wandera who sadly passed away weeks before publishing. Wandera was a chief taxonomist at Uganda’s National Fisheries Resources Research Institute who studied cichlids and other fish in the region, discovering many species.

Publication:
J.I. Meier et al. (2023) ‘Cycles of fusion and fission enabled rapid parallel adaptive radiations in African cichlids.’ Science. DOI: 10.1126/science.ade2833 

Funding:
This research was supported by Swiss National Science Foundation grant and a Royal Society University Research Fellowship at the Wellcome Sanger Institute. For full funding acknowledgements, please refer to the publication.

Selected websites:

University of Bern
The University of Bern is a public institution, based in Switzerland’s capital city, with a strong focus on providing excellence in research and teaching. The university has some 18,400 students benefiting from a full range of courses in most disciplines at undergraduate and graduate levels, as well as continuing education. The University of Bern is one of the world’s leading universities in climate research, space research as well as health and medicine. It hosts international research platforms, national centers of competence in research and trans- and interdisciplinary programs. The institution offers state-of-the-art facilities to its students and teaching staff at its eight faculties. http://www.unibe.ch/index_eng.html

Eawag: Swiss Federal Institute of Aquatic Science and Technology
Eawag is one of the world’s leading aquatic research institutes. With its professional diversity, close partnerships with practitioners and an international network, Eawag offers an excellent environment for the study of water as a habitat and resource, for identifying problems at an early stage and for developing widely accepted solutions. 

The Wellcome Sanger Institute
The Wellcome Sanger Institute is a world leader in genomics research. We apply and explore genomic technologies at scale to advance understanding of biology and improve health.  Making discoveries not easily made elsewhere, our research delivers insights across health, disease, evolution and pathogen biology.  We are open and collaborative; our data, results, tools, technologies and training are freely shared across the globe to advance science.
Funded by Wellcome, we have the freedom to think long-term and push the boundaries of genomics. We take on the challenges of applying our research to the real world, where we aim to bring benefit to people and society.
Find out more at www.sanger.ac.uk or follow us on Twitter, Instagram, Facebook, LinkedIn and on our Blog.

About Wellcome
Wellcome supports science to solve the urgent health challenges facing everyone. We support discovery research into life, health and wellbeing, and we’re taking on three worldwide health challenges: mental health, infectious disease and climate and health. https://wellcome.org/

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JOURNAL

Science

DOI

10.1126/science.ade2833 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Cycles of fusion and fission enabled rapid parallel adaptive radiations in African cichlids.

ARTICLE PUBLICATION DATE

29-Sep-2023

 

Did animal evolution begin with a predatory lifestyle?

New research findings on Aiptasia sea anemones point to early evolutionary events in multicellular organisms

Peer-Reviewed Publication

HEIDELBERG UNIVERSITY

 

IMAGE: 

PICTURED IS AN EARLY PLANULA LARVAL STAGE OF THE SEA ANEMONE AIPTASIA (CYAN NUCLEI AND GREEN STINGING CELLS) PREYING ON A CRUSTACEAN NAUPLIUS (GREEN) OF THE COPEPOD TISBE SP.

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CREDIT: IRA MÄGELE AND ULRIKE ENGEL

Were the first animals predators or filter feeders like the sponges living in today’s oceans? And what role did symbiosis with algae play, as with reef-building corals? Surprising findings by a research group led by Prof. Dr Thomas W. Holstein of Heidelberg University on the development of sea anemones suggest that a predatory lifestyle moulded their evolution and had a significant impact on the origin of their nervous system. The researchers were able to show that the young life stages (larvae) of the small sea anemone Aiptasia actively feed on living prey and are not dependent on algae. To capture its prey, the anemone larvae use specialised stinging cells and a simple neuronal network.

In the early embryonic development of multicellular organisms, gastrulation plays a key role. “In its simplest form, the gastrula develops from a hollow sphere of cells, the blastula, forming a larval stage with gut and mouth; imagine pushing a ball inwards at one side. All animals pass through this gastrula stage, which could also have existed at the beginning of animal evolution,” explains Prof. Holstein, a development and evolutionary biologist at the Centre for Organismal Studies (COS) at Ruperto Carola. Ira Mägele, a member of his research group, succeeded in proving that already in the late gastrula stage, the larvae of the Aiptasia sea anemone capture prey of suitable size with their stinging cells, ingest them with their mouth and digest them in their primitive gut.

The Aiptasia sea anemone is a model system for research on endosymbiosis in corals and other cnidarians. “Corals live in nutrient-poor waters and as larvae or young polyps, take up symbiotic algae cells. In Aiptasia, however, this process is important for adults but does not lead to growth and settlement of the larvae, suggesting that nutrition is a critical step in closing the life cycle,” states Thomas Holstein. Laboratory studies of the nutritional conditions showed that the food for the tiny Aiptasia larvae had to be small enough and alive. Nauplius larvae of Tisbe copepods, 50 to 80 micrometres small, are of similar size to Aiptasia larvae, making them an ideal food.

The larvae increase continually and rapidly in size, followed by settlement on the substrate and metamorphosis into primary polyps. “In this way, we were able to grow mature polyps as well as their descendants for the first time,” explains Ira Mägele. Dr Elizabeth Hambleton, a participating researcher from the University of Vienna (Austria), stresses: “By thus closing the life cycle of Aiptasia, it will finally be possible to carry out necessary molecular genetic experiments required for functional studies on this key endosymbiotic model organism”. Prof. Dr Annika Guse from Ludwig Maximilian University of Munich, also a study co-author, views this experimental approach as a breakthrough for work on this model system.

As Prof. Holstein underscores, the data obtained paint a new picture of the predatory lifestyle as a primary characteristic of the cnidarian gastrula. Evolutionary theorist Ernst Haeckel (1834 to 1919) first posed the “gastrula hypothesis”. “But Haeckel’s hypothetical gastrula was a particle-filtering life form, like sponges. In contrast, the predatory gastrula of Aiptasia and other cnidarians possess specialised stinging cells used for capturing prey.” The predatory lifestyle of gastrula-like forms with extrusive organelles that excrete toxins and are likewise found in single-celled organisms and simple worms, adds the Heidelberg biologist, could have been a critical driver of the early evolution of multicellular organisms and the development of complex, organised nervous systems.

The results of the study were published in the journal PNAS. Funding was provided by the German Research Foundation as part of Heidelberg University’s “Mechanisms and Functions of Wnt Signaling” Collaborative Research Centre as well as the ERC Consolidator Grant “SYMCELLS – Resolving the molecular mechanisms of intracellular coral-algal symbiosis” led by Prof. Guse.

Pictured is a larva of the small sea anemone Aiptasia (cyan nuclei) with an ingested crustacean nauplius (green) of the copepod Tisbe sp.

CREDIT

Ira Mägele and Ulrike Engel

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2311872120 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

A predatory gastrula leads to symbiosis-independent settlement in Aiptasia.