. Scientific Frontline

Wednesday, April 12, 2023

Scientists Trace Key Innovation in Our Camera-like Vision to Bacteria

Photo Credit: Colin Lloyd

Discovery comes to light with evidence that vertebrates acquired a special protein from bacteria more than 500 million years ago

Humans and other organisms with backbones come equipped with an evolutionary marvel: eyes that function like cameras to provide a finely tuned visual system. Due to its complexity, Charles Darwin described the eye as one of the greatest potential challenges to his theory of natural selection through incremental evolutionary steps.

A notable difference between vertebrate and invertebrate vision is rooted in a unique protein responsible for the specialization of cells that are critical for vision. Mutations in the protein have been known to cause a variety of diseases such as retinitis pigmentosa, but its evolutionary origin has remained elusive with no obvious genetic precursor.

Scientists track evolution of microbes on the skin’s surface

An SEM image showing four yellow-colored, spheroid shaped, Staphylococcus aureus bacteria.
Image Credit: National Institute of Allergy and Infectious Diseases (NIAID)

Human skin is home to millions of microbes. One of these microbes, Staphylococcus aureus, is an opportunistic pathogen that can invade patches of skin affected by eczema, also known as atopic dermatitis.

In a new study, researchers at MIT and other institutions have discovered that this microbe can rapidly evolve within a single person’s microbiome. They found that in people with eczema, S. aureus tends to evolve to a variant with a mutation in a specific gene that helps it grow faster on the skin.

This study marks the first time that scientists have directly observed this kind of rapid evolution in a microbe associated with a complex skin disorder. The findings could also help researchers develop potential treatments that would soothe the symptoms of eczema by targeting variants of S. aureus that have this type of mutation and that tend to make eczema symptoms worse.

“This is the first study to show that Staph aureus genotypes are changing on people with atopic dermatitis,” says Tami Lieberman, an assistant professor of civil and environmental engineering and a member of MIT’s Institute for Medical Engineering and Science. “To my knowledge, this is the most direct evidence of adaptive evolution in the skin microbiome.”

Lieberman and Maria Teresa García-Romero, a dermatologist and assistant professor at the National Institute of Pediatrics in Mexico, are the senior authors of the study, which appears today in Cell Host and Microbe. Felix Key, a former MIT postdoc who is now a group leader at the Max Planck Institute for Infection Biology, is the lead author of the paper.

Humans need Earth-like ecosystem for deep-space living

Even on future cosmic outposts like Mars, depicted in this artistic rendering, humans must consider closely replicating natural conditions found on Earth, according to a new theory called Pancosmorio.
Illustration Credit: NASA/JPL

Can humans endure long-term living in deep space?

The answer is a lukewarm maybe, according to a new theory describing the complexity of maintaining gravity and oxygen, obtaining water, developing agriculture and handling waste far from Earth, which a Cornell researcher developed after examining the long-term physical needs of humans living far from Earth.

Dubbed the Pancosmorio theory – a word coined to mean “all world limit” – it was described in “Pancosmorio (World Limit) Theory of the Sustainability of Human Migration and Settlement in Space,” published in March in Frontiers in Astronomy and Space Sciences.

“For humans to sustain themselves and all of their technology, infrastructure and society in space, they need a self-restoring, Earth-like, natural ecosystem to back them up,” said co-author Morgan Irons, a doctoral student conducting research with Johannes Lehmann, the Liberty Hyde Bailey Professor in the School of Integrative Plant Science, College of Agriculture and Life Sciences. Her work focuses on soil organic carbon persistence under Earth’s gravity and varying gravity conditions. “Without these kinds of systems, the mission fails.”

Severe droughts devastate eucalyptus trees that pre-date Ice Age

Researchers documenting the loss of red stringybark trees in the Clare Valley, SA.
Photo Credit: Courtesy of University of South Australia

South Australian scientists have documented the catastrophic decline of a stand of red stringybark in the Clare Valley, a tree species that has survived in the region for 40,000 years but is now at risk of extinction due to climate change.

Two severe droughts driven by climate change since 2000 are blamed for “staggering losses” of an isolated population of the South Australian species Eucalyptus macrorhyncha  in the Spring Gully Conservation Park.

Multiple surveys led by University of South Australia environmental biologists Associate Professor Gunnar Keppel and Udo Sarnow have recorded tree and biomass losses of more than 40 per cent, during the Millennium Drought from 2000-2009 and the Big Dry from 2017-2019.

More than 400 trees were monitored over 15 years, within two years of their dieback first being reported in 2007.

Small and simple key to evolution success of mammals

Artistic reconstruction of early mammal ancestors (species: Hadrocodium wui) shown hunting insect prey, illustrating how the adoption of an insectivorous diet and miniaturization played an important role in mammal evolution.
Illustration Credit: Dr Stephan Lautenschlager, University of Birmingham

Ancestors of modern mammals evolved into one of the most successful animal lineages by starting out small and simple, researchers have found.

A new study, published today in Communications Biology, shows that skull bones were successively reduced in early mammals around 150 to 100 million years ago.  

The research further demonstrated that alongside the reduction of skull bones, early mammals also became a lot smaller, some of which had a skull length of only 10-12 mm. This miniaturization considerably restricted the available food sources and early mammals adapted to feeding mostly on insects, allowing them to thrive in the shadows of dinosaurs.

In many vertebrate groups (animals with a back bone), such as fishes and reptiles, the skull and lower jaw are composed of numerous bones. This was also the case in the earliest ancestors of modern mammals over 300 million years ago.

Nanotubes as an optical stopwatch for the detection of messenger substances

Bochum research team: Linda Sistemich and Sebastian Kruß
Photo Credit: © RUB, Kramer

Carbon nanotubes not only lighten in the presence of dopamine, but also longer. The lighting duration can serve as a new measurement for the detection of messenger substances.

An interdisciplinary research team from Bochum and Duisburg has found a new way to detect the important messenger substance dopamine in the brain. The researchers used carbon nanotubes for this. In previous studies, the team led by Prof. Dr. Sebastian Kruß has already shown that the tubes light up in the presence of dopamine. Now the interdisciplinary group showed that the duration of the lighting also changes. "It is the first time that an important messenger like dopamine has been detected in this way," says Sebastian Kruß. “We are convinced that this will open up a new platform that will also enable better detection of other human messenger substances such as serotonin. "The work was a cooperation between Kruß’ two working groups in physical chemistry at the Ruhr University Bochum and the Fraunhofer Institute for Microelectronic Circuits and Systems (IMS).

The results are described by a team led by Linda Sistemich and Sebastian Kruß from the Ruhr University Bochum together with colleagues from the IMS and the University of Duisburg-Essen in the journal Angewandte Chemie - International Edition, published online on 9. March 2023.

95-million-year-old sauropod dinosaur skull first of its kind in Australia

Diamantinasaurus matildae head.
Illustration Credit: Elena Marian/ Australian Age of Dinosaurs Musuem of Natural History

A Curtin University-led research team has analyzed Australia’s first nearly complete sauropod dinosaur skull found in Queensland, Australia, gaining a better understanding of the animal’s anatomy, relationships to other sauropods, and feeding habits.

The research, published in Royal Society Open Science and completed in collaboration with the Australian Age of Dinosaurs Museum of Natural History, found that the skull – belonging to a dinosaur nicknamed ‘Ann’ – was from the species Diamantinasaurus matildae. Diamantinasaurus is a member of the dinosaur group Sauropoda, known for having small heads, long necks and tails, barrel-like bodies, and four columnar legs.

Lead researcher and paleontologist Dr Stephen Poropat, from Curtin’s School of Earth and Planetary Sciences, said ‘Ann’ is the first sauropod dinosaur found in Australia to include most of the skull, and also the first Diamantinasaurus specimen to preserve a back foot.

“I was lucky enough to be involved in this Australian-first discovery. Being able to lead the research on these fossils was a huge privilege. This skull gives us a rare glimpse into the anatomy of this enormous sauropod that lived in northeast Australia almost 100 million years ago,” Dr Poropat said.

Sugar molecule in blood can predict Alzheimer’s

Photo Credit: Gerd Altmann

Early diagnosis and treatment of Alzheimer’s disease requires reliable and cost-effective screening methods. Researchers at Karolinska Institutet have now discovered that a type of sugar molecule in blood is associated with the level of tau, a protein that plays a critical role in the development of severe dementia. The study, which is published in Alzheimer's & Dementia, can pave the way for a simple screening procedure able to predict onset ten years in advance.

“The role of glycans, structures made up of sugar molecules, is a relatively unexplored field in dementia research,” says the study’s first author Robin Zhou, medical student and affiliated researcher at the Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet. “We demonstrate in our study that blood levels of glycans are altered early during the development of the disease. This could mean that we’ll be able to predict the risk of Alzheimer’s disease with only a blood test and a memory test.”

In Alzheimer’s disease, the neurons of the brain die, which is thought to be a result of the abnormal accumulation of the proteins amyloid beta and tau. Clinical trials for Alzheimer’s drugs show that treatment should commence early in the pathological process, before too many neurons have died, to reverse the process before it is too late.

The brain’s cannabinoid system protects against addiction

Test participants’ emotional reactions are measured using electrodes that record tension in the small facial muscles. From left: Madeleine Jones and Irene Perini. 
Photo Credit: Thor Balkhed

High levels of the body’s own cannabinoid substances protect against developing addiction in individuals previously exposed to childhood maltreatment, according to a new study. Those who had not developed an addiction following childhood maltreatment seem to process emotion-related social signals better.

 Childhood maltreatment has long been suspected to increase the risk of developing a drug or alcohol addiction later in life. Researchers at Linköping University have previously shown that this risk is three times higher if you have been exposed to childhood maltreatment compared with if you have not, even when accounting for confounds from genetics and other familial factors.

“There’s been a lot of focus on addiction as a disease driven by a search for pleasure effects and euphoria, but for many it has more to do with the drugs’ ability to suppress negative feelings, stress sensitivity, anxiety and low mood. Based on this, we and other researchers have had a theory that if affected in childhood, the function of the brain’s distress systems is altered, and that this may contribute to addiction risk in adulthood,” says Markus Heilig, professor and director of the Center for Social and Affective Neuroscience, CSAN, at Linköping University and consultant at the Psychiatric Clinic of the University Hospital in Linköping.

Researchers devise new system for turning seawater into hydrogen fuel

Researchers collect seawater in Half Moon Bay, California, in January 2023 for an experiment that turned the liquid into hydrogen fuel. From left: Joseph Perryman, a SLAC and Stanford postdoctoral researcher; Daniela Marin, a Stanford graduate student in chemical engineering and co-author; Adam Nielander, an associate staff scientist with the SUNCAT, a SLAC-Stanford joint institute; and Charline Rémy, a visiting scholar at SUNCAT.
Photo Credit: Adam Nielander/SLAC National Accelerator Laboratory

The SLAC-Stanford team pulled hydrogen directly from ocean waters. Their work could help efforts to generate low-carbon fuel for electric grids, cars, boats and other infrastructure.

Seawater’s mix of hydrogen, oxygen, sodium and other elements makes it vital to life on Earth. But that same complex chemistry has made it difficult to extract hydrogen gas for clean energy uses. 

Now, researchers at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University with collaborators at the University of Oregon and Manchester Metropolitan University have found a way to tease hydrogen out of the ocean by funneling seawater through a double-membrane system and electricity. Their innovative design proved successful in generating hydrogen gas without producing large amounts of harmful byproducts. The results of their study, published in Joule, could help advance efforts to produce low-carbon fuels.

“Many water-to-hydrogen systems today try to use a monolayer or single-layer membrane. Our study brought two layers together,” said Adam Nielander, an associate staff scientist with the SUNCAT Center for Interface Science and Catalysis, a SLAC-Stanford joint institute. “These membrane architectures allowed us to control the way ions in seawater moved in our experiment.” 

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