. Scientific Frontline

Wednesday, December 20, 2023

Insects already had a variety of defense strategies in the Cretaceous

Larva of a wedge-shaped beetle in amber, which could have lived inside other insects like its modern counterparts. 
Image Credit: © Carolin Haug

Analyses of amber show that insect larvae were already using a wide variety of tactics to protect themselves from predators 100 million years ago.

Early life stages of insects fulfill important functions in our ecosystems. They decompose dead bodies and wood, forming soil and returning various elements into material cycles. Not least, they are a major food source for many larger animals such as birds and mammals. This has led to many insect larvae developing structures and strategies for reducing the danger of being eaten. These include features like spines and hairs, but also camouflage and concealment. Over millions of years, a wide variety of such adaptation strategies have developed.

Researchers at LMU and the universities of Greifswald and Rostock have studied particularly well-preserved fossils from Burmese amber and have been able to demonstrate that such anti-predator mechanisms had already evolved very diverse forms in insect larvae during the Cretaceous period 100 million years ago. This includes well-known strategies such as that employed by lacewing larvae, which carry various plant and animal materials on their back to give them camouflage, or the ploy of mimicking the appearance of certain plant parts.

Discovery: plants use “trojan horse” to fight mold invasions

Photo Credit: Gábor Adonyi

UC Riverside scientists have discovered a stealth molecular weapon that plants use to attack the cells of invading gray mold. 

If you’ve ever seen a fuzzy piece of fruit in your fridge, you’ve seen gray mold. It is an aggressive fungus that infects more than 1,400 different plant species: almost all fruits, vegetables, and many flowers. It is the second most damaging fungus for food crops in the world, causing billions in annual crop losses.

A new paper in the journal Cell Host & Microbe describes how plants send tiny, innocuous-seeming lipid “bubbles” filled with RNA across enemy lines, into the cells of the aggressive mold. Once inside, different types of RNA come out to suppress the infectious cells that sucked them in.

“Plants are not just sitting there doing nothing. They are trying to protect themselves from the mold, and now we have a better idea how they’re doing that,” said Hailing Jin, Microbiology & Plant Pathology Department professor at UCR and lead author of the new paper.

Previously, Jin’s team discovered that plants are using the bubbles, technically called extracellular vesicles, to send small RNA molecules able to silence genes that make the mold virulent. Now, the team has learned these bubbles can also contain messenger RNA, or mRNA, molecules that attack important cellular processes, including the functions of organelles in mold cells. 

Toxic chemicals found in oil spills and wildfire smoke detected in killer whales

Orcas (killer whales)
Photo Credit: Bart van Meele

Toxic chemicals produced from oil emissions and wildfire smoke have been found in muscle and liver samples from Southern Resident killer whales and Bigg’s killer whales.

A study published in Scientific Reports is the first to find polycyclic aromatic hydrocarbons (PAHs) in orcas off the coast of B.C., as well as in utero transfer of the chemicals from mother to fetus.

“Killer whales are iconic in the Pacific Northwest—important culturally, economically, ecologically and more. Because they are able to metabolically process PAHs, these are most likely recent exposures. Orcas are our canary in the coal mine for oceans, telling us how healthy our waters are,” said senior author Dr. Juan José Alava, principal investigator of the UBC Ocean Pollution Research Unit and adjunct professor at Simon Fraser University.

PAHs are a type of chemical found in coal, oil and gasoline which research suggests are carcinogenic, mutagenic, and have toxic effects on mammals. Their presence in the ocean comes from several sources, including oil spills, burning coal and forest fire smoke particles.

Researchers analyzed muscle and liver samples from six Bigg’s, or transient, killer whales and six Southern Resident killer whales (SRKWs) stranded in the northeastern Pacific Ocean between 2006 and 2018. They tested for 76 PAHs and found some in all samples, with half the PAHs appearing in at least 50 per cent of the samples. One compound, a PAH derivative called C3-phenanthrenes/anthracenes, accounted for 33 per cent of total contamination across all samples. These forms of PAHs, known as alkylated PAHs, are known to be more persistent, toxic, and to accumulate more in the bodies of organisms or animals than parental PAHs.

Tuesday, December 19, 2023

Enlarged Spaces in Infant Brains Linked to Higher Risk of Autism, Sleep Problems

Dea Garic, PhD, and Mark Shen, PhD, both in the UNC School of Medicine’s Department of Psychiatry, have found that enlarged perivascular spaces in the brains of babies, caused by an accumulation of excess cerebrospinal fluid, have a 2.2 times greater chance of developing autism later in life.
Photo Credit: Courtesy of University of North Carolina at Chapel Hill

Throughout the day and night, cerebrospinal fluid (CSF) pulses through small fluid-filled channels surrounding blood vessels in the brain, called perivascular spaces, to flush out neuroinflammation and other neurological waste. A disruption to this vital process can lead to neurological dysfunction, cognitive decline, or developmental delays.

For the first time, researchers Dea Garic, PhD, and Mark Shen, PhD, both at the UNC School of Medicine’s Department of Psychiatry, discovered that infants with abnormally enlarged perivascular spaces have a 2.2 times greater chance of developing autism compared to infants with the same genetic risk. Their research also indicated that enlarged perivascular spaces in infancy are associated with sleep problems seven to 10 years after diagnosis.

“These results suggest that perivascular spaces could serve as an early marker for autism,” said Garic, assistant professor of psychiatry and a member of the Carolina Institute for Developmental Disabilities (CIDD).

The researchers studied infants at increased likelihood for developing autism, because they had an older sibling with autism. They followed these infants from 6-24 months of age, before the age of autism diagnosis. Their study, published in JAMA Network Open, found that thirty percent of infants who later developed autism had enlarged perivascular spaces by 12 months. By 24 months of age, nearly half of the infants diagnosed with autism had enlarged perivascular spaces.

Molecular jackhammers’ ‘good vibrations’ eradicate cancer cells

Ciceron Ayala-Orozco is a research scientist in the Tour lab at Rice University, and lead author on the study.
Photo Credit: Jeff Fitlow/Rice University

The Beach Boys’ iconic hit single “Good Vibrations” takes on a whole new layer of meaning thanks to a recent discovery by Rice University scientists and collaborators, who have uncovered a way to destroy cancer cells by using the ability of some molecules to vibrate strongly when stimulated by light.

The researchers found that the atoms of a small dye molecule used for medical imaging can vibrate in unison ⎯ forming what is known as a plasmon ⎯ when stimulated by near-infrared light, causing the cell membrane of cancerous cells to rupture. According to the study published in Nature Chemistry, the method had a 99 percent efficiency against lab cultures of human melanoma cells, and half of the mice with melanoma tumors became cancer-free after treatment.

“It is a whole new generation of molecular machines that we call molecular jackhammers,” said Rice chemist James Tour, whose lab has previously used nanoscale compounds endowed with a light-activated paddlelike chain of atoms that spins continually in the same direction to drill through the outer membrane of infectious bacteria, cancer cells and treatment-resistant fungi.

Researchers Find They Can Stop Degradation of Promising Solar Cell Materials

An illustration of metal halide perovskites. They are a promising material for turning light into energy because they are highly efficient, but they also are unstable. Georgia Tech engineers showed in a new study that both water and oxygen are required for perovskites to degrade. The team stopped the transformation with a thin layer of another molecule that repelled water.
Image Credit: Courtesy of Juan-Pablo Correa-Baena

Georgia Tech materials engineers have unraveled the mechanism that causes degradation of a promising new material for solar cells — and they’ve been able to stop it using a thin layer of molecules that repels water.

Their findings are the first step in solving one of the key limitations of metal halide perovskites, which are already as efficient as the best silicon-based solar cells at capturing light and converting it into electricity. They reported their work in the Journal of the American Chemical Society.

“Perovskites have the potential of not only transforming how we produce solar energy, but also how we make semiconductors for other types of applications like LEDs or phototransistors. We can think about them for applications in quantum information technology, such as light emission for quantum communication,” said Juan-Pablo Correa-Baena, assistant professor in the School of Materials Science and Engineering and the study’s senior author. “These materials have impressive properties that are very promising.”

Genetic Diversity of Wild North American Grapes Mapped

Dario Cantù, a professor in the Department of Viticulture and Enology, in the grape orchard outside the Robert Mondavi Institute for Wine and Food Science.
Photo Credit: Jael Mackendorf/UC Davis

Wild North American grapes are now less of a mystery after an international team of researchers led by the University of California, Davis, decoded and catalogued the genetic diversity of nine species of this valuable wine crop.

The research, published in the journal Genome Biology, uncovers critical traits that could accelerate grape breeding efforts, particularly in tackling challenges like climate change, saline environments and drought.

“This research marks a significant step in understanding the genetics of grapevines,” said Dario Cantù, the senior author on the journal article and a professor in the Department of Viticulture and Enology. “It lays the groundwork for future advancements in grape breeding by identifying key genes responsible for important traits.”

The research team developed and used state-of-the-art technology to construct a comprehensive pangenome, which is a complete genetic blueprint, of wild grape species.

This so-called super-pangenome of nine species allowed the team to map genetic diversity, identify similarities or differences among them, and pinpoint specific traits that breeders may want to incorporate. First author Noé Cochetel, a postdoctoral researcher in Cantù’s lab, did the analyses and played a pivotal role in the project.

Scientists reveal superconductor with on-off switches

(A) The material used in this study consists of stacked layers of ferromagnetic atoms and superconducting atoms. (B) Applying a small magnetic field induces superconductivity, while (C) low temperatures boost that superconductivity.
Illustration Credit: Courtesy Shua Sanchez, University of Washington

As industrial computing needs grow, the size and energy consumption of the hardware needed to keep up with those needs grows as well. A possible solution to this dilemma could be found in superconducting materials, which can reduce that energy consumption exponentially. Imagine cooling a giant data center full of constantly running servers down to nearly absolute zero, enabling large-scale computation with incredible energy efficiency.

Physicists at the University of Washington and the U.S. Department of Energy’s (DOE) Argonne National Laboratory have made a discovery that could help enable this more efficient future. Researchers have found a superconducting material that is uniquely sensitive to outside stimuli, enabling the superconducting properties to be enhanced or suppressed at will. This enables new opportunities for energy-efficient switchable superconducting circuits. The paper was published in Science Advances.

Superconductivity is a quantum mechanical phase of matter in which an electrical current can flow through a material with zero resistance. This leads to perfect electronic transport efficiency. Superconductors are used in the most powerful electromagnets for advanced technologies such as magnetic resonance imaging, particle accelerators, fusion reactors and even levitating trains. Superconductors have also found uses in quantum computing.

A temporary tug-of-war: a minimal system unlocks cellular transport secrets

A visual representation of the findings. The net number of cargo-bound kinesin or dynein motor proteins engaging with the microtubule track decides whether it is moved in positive or negative direction. When both, kinesins and dyneins engage with the microtubule, the transport is often interrupted. Occasionally, the cargo is being pulled by motor proteins in opposite directions before one finally wins.
Illustration Credit: Diez Lab

Cells are busy conglomerates. Different molecules and organelles have to be delivered to different locations at a specific time.  How exactly they are reaching their destinations is a long-standing question in biology. Researchers from the Diez group at the B CUBE – Center for Molecular Bioengineering of TUD Dresden University of Technology and the Santen group at the Center for Biophysics at the Saarland University have now built a minimal version of a cell transport system outside a cell. Using the minimal system, the team discovered the principles of how cells control the direction of transport. The new study was published in the journal Nature Communications.

Cells are like busy factories. They need to transport molecules and organelles (cargo) reliably to different destinations within the cell. Defects in cellular transport have been associated with many diseases including Alzheimer’s, Parkinson’s, and Huntington’s. The transport relies on a system of cellular train tracks known as microtubules. Two types of motor proteins, kinesin and dynein, can move in opposite directions along the microtubules to carry the cargo to its destination. At any given time, the cargo is attached to multiple copies of kinesin and dynein. Yet, it moves in only one direction. It is unclear what determines the moving direction.

When the Cellular Waste Collector Doesn’t Show Up

Verian Bader and Konstanze Winklhofer (right) are on the trail of the development of neurodegenerative diseases.
Photo Credit: © RUB, Marquard

Researchers have identified a mechanism that promotes the breakdown of harmful protein deposits. If it malfunctions, it can lead to Parkinson’s disease.

NEMO, a protein that is primarily associated with signaling processes in the immune system, prevents the deposition of protein aggregates that occur in Parkinson’s disease. For this purpose, it binds to certain protein chains that serve as markers for cellular waste removal, thus promoting the degradation of the harmful aggregates. A research team headed by Professor Konstanze Winklhofer from Ruhr University Bochum, Germany, has shed light on how this mechanism works. The team published their findings in the journal Nature Communications on December 19, 2023. In follow-up studies, the team is investigating ways to harness the findings for therapeutic strategies.

Looking for targeted therapeutic approaches

Neurodegenerative diseases, such as Parkinson’s or Alzheimer’s disease, are associated with the deposition of protein aggregates in the brain. These aggregates accumulate when the cellular waste removal system is defective or overloaded. In Parkinson’s disease, aggregates consisting primarily of the protein ⍺-synuclein are found in certain regions of the brain. “The fact that such aggregates occur, which are referred to as Lewy bodies, is a key feature of Parkinson’s disease,” explains Konstanze Winklhofer.

The misfolding and aggregation of ⍺-synuclein is of crucial importance for processes that lead to the loss of function and death of neuronal cells and contribute to the progression of the disease. Researchers from various disciplines around the world are therefore aiming to decipher these processes at a cellular and molecular level, in order to develop targeted therapeutic approaches.

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