Ribosomal protein exhibits remarkable evolutionary transformation

The cryo-EM maps and atomic models showing the structure of ribosomal protein msL1 in the ribosome from microsporidian parasites V. necatrix (first row), and protein msL2 in the ribosome from microsporidian parasites E. cuniculi (second row).
Illustration Credit: Leon Schierholz

A team of researchers from the Universities of Newcastle and Umeå has discovered that a ribosomal protein exhibits a remarkable evolutionary transformation, with its three-dimensional structure changing drastically while its sequence remains relatively conserved.

The protein, known as msL1/msL2, is found in ribosomes of parasitic microorganisms called microsporidia, and it is suggested to play a role in stabilizing the highly reduced protein synthesis machinery in these unique organisms. 

“Despite its conserved sequence, msL1/msL2 adopts distinct folds in two different microsporidian species, Encephalitozoon cuniculi, and Vairimorpha necatrix. This structural divergence is particularly striking given that the two proteins share approximately 41% sequence similarity,” comments Léon Schierholz, one of the authors from Umeå University.  

Aquatic Insects in Restored Streams Need More Rocks to Lay Their Eggs

A caddisfly egg mass sits on the underside of a protruding rock.
Photo Credit: Brad Taylor, NC State University.

Likening it to providing more runways at busy airports, researchers at North Carolina State University found in a new study that adding protruding rocks to restored streams can help attract female aquatic insects that lay their eggs on the rock bottoms or sides.

More eggs that hatch into larval insects is great news for stream restoration because the re-establishment of organisms, such as insects, is often slower than expected in restored streams, says Brad Taylor, associate professor of applied ecology at NC State and corresponding author of a paper describing the research. A thriving population of stream insects generally portends good water quality, overall stream health, and provides food for fish, amphibians, reptiles, and even birds, he adds.

Most stream insects use rocks protruding above the water as runways to land on, then crawl underwater and attach their eggs to the underside of the rocks. Because restored streams sometimes fail to regain their abundance of aquatic insects even decades following restoration, researchers were interested in testing whether increasing egg-laying habitat the rock landing areas would increase the abundance and diversity of insect eggs and larvae.

Taylor and NC State graduate student Samantha Dilworth selected 10 restored streams in northwestern North Carolina and added protruding rocks gathered near the streams to five of them; the other five restored streams did not receive additional rocks.

UNC Researchers Reveal Prevalence of Persistent Symptoms in Patients with Microscopic Colitis

Walker Redd, MD, a clinical outcomes and epidemiology fellow in the Division of Gastroenterology and Hepatology, Department of Medicine.
Photo Credit: Courtesy of University North Carolina, School of Medicine

It’s a hidden cause of diarrhea and the development of the disease is poorly understood. Multiple factors work against the diagnosis of microscopic colitis, an inflammatory digestive disease, because the symptom distress compared to patients with other causes of chronic diarrhea remains unknown. Now, a new study published in journal Gastro Hep Advances, shows patients may be unsure of a diagnosis based on their colonoscopy results, patients may not be prescribed the proper medications, and many patients may remain symptomatic one year after colonoscopy.

The study, led by corresponding author Walker Redd, MD, a clinical outcomes and epidemiology fellow in the Division of Gastroenterology and Hepatology at the UNC School of Medicine, involved a cohort of patients from April 1, 2015 to December 22, 2020 enrolled at UNC Hospitals in Chapel Hill, NC. Patients participating in a follow-up survey included 74 with biopsy-confirmed microscopic colitis and 162 patients experiencing other causes of chronic diarrhea (diarrhea controls) after colonoscopy at a one-year follow-up.

“We thought it was important to better understand the burden of symptoms among those patients with microscopic colitis within the context of all patients undergoing colonoscopy to evaluate diarrhea,” Redd said.

Sugar analysis could reveal different types of cancer

By analyzing changes in glycan structures in the cell, researchers can detect different types of cancer.
Photo Credit: Mikhail Nilov

In the future, a little saliva may be enough to detect an incipient cancer. Researchers at the University of Gothenburg have developed an effective way to interpret the changes in sugar molecules that occur in cancer cells.

Glycans are a type of sugar molecule structure that is linked to the proteins in our cells. The structure of the glycan determines the function of the protein. It has been known for a while that changes in glycan structure can indicate inflammation or disease in the body. Now, researchers at the University of Gothenburg have developed a way to distinguish different types of structural changes, which may provide a precise answer to what will change for a specific disease.

“We have analyzed data from about 220 patients with 11 differently diagnosed cancers and have identified differences in the substructure of the glycan depending on the type of cancer. By letting our newly developed method, enhanced by AI, work through large amounts of data, we were able to find these connections,” says Daniel Bojar, associate senior lecturer in bioinformatics at the University of Gothenburg and lead author of the study published in Cell Reports Methods.

What Happens in the Brain While Daydreaming?

The findings provide a clue that daydreams may play a role in brain plasticity
Image Credit: Scientific Frontline 

You are sitting quietly, and suddenly your brain tunes out the world and wanders to something else entirely — perhaps a recent experience, or an old memory. You just had a daydream.

Yet despite the ubiquity of this experience, what is happening in the brain while daydreaming is a question that has largely eluded neuroscientists.

Now, a study in mice, published Dec. 13 in Nature, has brought a team led by researchers at Harvard Medical School one step closer to figuring it out.

The researchers tracked the activity of neurons in the visual cortex of the brains of mice while the animals remained in a quiet waking state. They found that occasionally these neurons fired in a pattern similar to one that occurred when a mouse looked at an actual image, suggesting that the mouse was thinking — or daydreaming — about the image. Moreover, the patterns of activity during a mouse’s first few daydreams of the day predicted how the brain’s response to the image would change over time.

The research provides tantalizing, if preliminary, evidence that daydreams can shape the brain’s future response to what it sees. This causal relationship needs to be confirmed in further research, the team cautioned, but the results offer an intriguing clue that daydreams during quiet waking may play a role in brain plasticity — the brain’s ability to remodel itself in response to new experiences.

Enzymes Can’t Tell Artificial DNA From the Real Thing

Like adding new letters to an existing language’s alphabet to expand its vocabulary, adding new synthetic nucleotides to the genetic alphabet could expand the possibilities of synthetic biology. This image shows a rendering of RNA polymerase (center) and a synthetic nucleotide (lower right).
Image Credit: UC San Diego Health Sciences

The genetic alphabet contains just four letters, referring to the four nucleotides, the biochemical building blocks that comprise all DNA. Scientists have long wondered whether it’s possible to add more letters to this alphabet by creating brand-new nucleotides in the lab, but the utility of this innovation depends on whether or not cells can actually recognize and use artificial nucleotides to make proteins.

Now, researchers at Skaggs School of Pharmacy and Pharmaceutical Sciences at the University of California San Diego have come one step closer to unlocking the potential of artificial DNA. The researchers found that RNA polymerase, one of the most important enzymes involved in protein synthesis, was able to recognize and transcribe an artificial base pair in exactly the same manner as it does with natural base pairs.

The findings, published in Nature Communications, could help scientists create new medicines by designing custom proteins.

Wildfires can unlock toxic metal particles from soils, Stanford study finds

Burned serpentine chaparral at McLaughlin Natural Reserve after the 2020 LNU Lightning Complex.
 Image Credit: Alandra Lopez

New research from Stanford University shows wildfires can transform a natural element in soils into a cancer-causing and readily airborne metal known as chromium 6.

Wildfires can transform a benign metal in soils and plants into toxic particles that easily become airborne, according to a new study from Stanford University.

Published in Nature Communications, the research documents high levels of a hazardous form of the metal chromium at wildfire sites with chromium-rich soils and certain kinds of vegetation compared to adjacent unburned sites. Known as hexavalent chromium or chromium 6, this is the same toxin made notorious by the 2000 film Erin Brockovich.

“Our study suggests far more attention should be paid to wildfire-modified chromium, and we presume additional metals as well, to more thoroughly characterize the overall threats wildfires pose to human health,” said lead study author Alandra Lopez, a postdoctoral scholar in Earth system science at the Stanford Doerr School of Sustainability.

This Japanese ‘dragon’ terrorized ancient seas

UC Associate Professor Takuya Konishi is an expert on ancient marine reptiles such as mosasaurs.
 Photo Credit: Joseph Fuqua II/UC

Researchers have described a Japanese mosasaur the size of a great white shark that terrorized Pacific seas 72 million years ago.

Extra-long rear flippers might have aided propulsion in concert with its long-finned tail. And unlike other mosasaurs, or large extinct marine reptiles, it had a dorsal fin like a shark’s that would have helped it turn quickly and with precision in the water.

University of Cincinnati Associate Professor Takuya Konishi and his international co-authors described the mosasaur and placed it in a taxonomic context in the Journal of Systematic Palaeontology.

The mosasaur was named for the place where it was found, Wakayama Prefecture. Researchers call it the Wakayama Soryu, which means blue dragon. Dragons are creatures of legend in Japanese folklore, Konishi said.

“In China, dragons make thunder and live in the sky. They became aquatic in Japanese mythology,” he said.

Trees are in trouble

 The trees in this lush, temperate forest in the Cascade Range of Washington are likely less resistant to drought than their counterparts in drier regions to the south.
Photo Credit Joan Dudney

This holiday season brings surprising news about your Christmas tree. Scientists just discovered that globally, trees growing in wetter regions are more sensitive to drought. That means if your tree hails from a more humid clime, it’s likely been spoiled for generations.

Scientists have long debated whether arid conditions make trees more or less resilient to drought. It seems intuitive that trees living at their biological limits will be most vulnerable to climate change, since even just a little extra stress could tip them past the brink. On the other hand, these populations have adapted to a harsher setting, so they might be more capable of withstanding a drought.

According to a new study in the journal Science by researchers at UC Santa Barbara and UC Davis, greater water availability could “spoil” trees by reducing their adaptations to drought. “And that’s really critical to understand when we’re thinking about the global vulnerability of forest carbon stocks and forest health,” said ecologist Joan Dudney, an assistant professor at UCSB’s Bren School of Environmental Science & Management and in the Environmental Studies Program. “You don’t want to be a ‘spoiled’ tree when facing a major drought.”

Clues to preventing Alzheimer’s come from patient who, despite genetics, evaded disease

A woman who never developed Alzheimer's despite a strong genetic predisposition may hold the key to stopping the disease in its tracks. Studying the woman's unique complement of genetic mutations, researchers at Washington University School of Medicine in St. Louis have found clues that could help cut the link between the early, asymptomatic stage and the late stage, when cognitive decline sets in.
Image Credit: AartlistDesign

Alzheimer’s disease has plagued one large Colombian family for generations, striking down half of its members in the prime of life. But one member of that family evaded what had seemed would be fate: Despite inheriting the genetic defect that caused her relatives to develop dementia in their 40s, she stayed cognitively healthy into her 70s.

Researchers at Washington University School of Medicine in St. Louis now think they know why. A previous study had reported that, unlike her relatives, the woman carried two copies of a rare variant of the APOE gene known as the Christchurch mutation. In this study, researchers used genetically modified mice to show that the Christchurch mutation severs the link between the early phase of Alzheimer’s disease, when a protein called amyloid beta builds up in the brain, and the late phase, when another protein called tau accumulates and cognitive decline sets in. So the woman stayed mentally sharp for decades, even as her brain filled with massive amounts of amyloid. The findings, published in the journal Cell, suggest a new approach to preventing Alzheimer’s dementia.