. Scientific Frontline

Wednesday, March 29, 2023

How whale shark rhodopsin evolved to see, in the deep blue sea!

Whale shark
Photo Credit: Mitsumasa Koyanagi, OMU

A new study reveals that the photoreceptor rhodopsin of whale sharks (Rhincodon typus), pictured here, evolved to improve sight for the low-light low-temperature deep-sea environment in a unique way.

A research group including Professors Mitsumasa Koyanagi and Akihisa Terakita of the Osaka Metropolitan University Graduate School of Science has investigated both the genetic information and structure of the photoreceptor rhodopsin, responsible for detecting dim light, of whale sharks to investigate how they can see in the dim light at extreme depths. The research group compared the whale sharks to zebra sharks, which are considered their closest relative, and brown-banded bamboo sharks, which are in the same group: the order orectolobiformes—commonly known as carpet sharks.

“This research used genetic information and molecular biological techniques to achieve stunning results—without harming whale sharks’ or their biology. Our research approach is to use these techniques to provide clues that reveal the mysteries of how these organisms live,” explained Professor Koyanagi. “The beautiful part is that it even works for species where information is limited, such as large or wild animals that are difficult to observe or follow in their natural habitat.”

Coronavirus causes chaos in infected cells’ RNA

Illustration Credit: Fusion Medical Animation

Coronavirus disease (COVID-19) hijacks parts of infected cells' vital RNA machinery, thereby blocking important functions in the cells. These damaging changes in the RNA can likely be reversed, potentially leading to new drugs against COVID-19, University of Gothenburg researchers show.

Genetic material in the body's cells consists of DNA, which serves as long-term storage of genetic information. RNA carries this encoded information to the cells for transcription and translation. These processes enable them to make proteins, which perform most intracellular tasks. The cells' RNA is modifiable to allow correct transfer of the DNA information to the proteins. In recent years, scientific understanding of the complexity and importance of these RNA modifications has grown.

Drastic impact

It has been shown that RNA modifications take place in various viruses, but exactly how the viruses affect the RNA modification processes when they infect cells is unknown. This study reports that SARS-CoV-2 infection disrupts the RNA modifications, and the extent of these RNA modification changes surprised the researchers.

One of the modifications affected by SARS-CoV-2, known as m6A (a multifaceted regulator of gene expression), is highly important for RNA’s basic functions, including transportation of data to the protein-making parts of the cell, and transcription and translation into amino acids there.

“We were surprised at the extent and drastic scale of m6A RNA modification loss in SARS-CoV-2 infection. We also found that the coronavirus variants have differing effects on m6A levels,” says Tanmoy Mondal, researcher at Sahlgrenska Academy, University of Gothenburg, who led the project.

Tuesday, March 28, 2023

Preserving the stars: light pollution and what you can do about it

Astrophysicist Ms Kirsten Banks explains what we can do to reverse the impact of "light glow".
Photo Credit: UNSW Sydney.

An astrophysicist from UNSW Sydney explains why it’s so important that we can all look up and see the stars. 

Astronomer Carl Sagan famously said that there were more stars in the universe than grains of sand on earth.  

It has been estimated that there are over 100 billion stars in the Milky Way galaxy. While there is a limit to how many stars we can see from earth with the naked eye, that number is dramatically reducing due to light pollution. 

“We should be able to see around 2500 stars with the naked eye on any night, and we can see about 125 of them at best in Sydney,” says astrophysicist, proud Wiradjuri woman and UNSW PhD candidate Ms. Kirsten Banks.

In fact, in a recent study published in Science, data collected by citizen scientists around the world found light pollution is increasing at a rate that is equivalent to the brightness of the sky doubling every eight years.  

This latest research continues to expose the extent to which we’re losing the darkness of our night sky. Not being able to look up and see the stars will have significant cultural impacts, but there are steps we can all be taking to reduce the effect of light pollution.

Turtle and crocodile species with unique characteristics are more likely to go extinct

A Mugger Crocodile (Crocodylus palustris). In Pakistan, this species is still illegally hunted for its skin.
Image Credit: Bishnu Sarangi

New research led by the University of Oxford has revealed that the most endangered turtle and crocodile species are those that are most unique. Their loss could have widespread impacts on the ecosystems they live in since they carry out critical processes important for many other species. The results have been published in Nature Communications.

"When it comes to the conservation of turtles and crocodiles, we are dealing with a critical scenario. Furthermore, our actions are affecting unevenly more so those species that are characterized by unique life strategies. Once they are gone, these life strategies will be gone too, with no other species being able to provide a back-up." 
Professor Rob Salguero-Gómez, Department of Biology, University of Oxford

Turtles and crocodiles are two of the world's most endangered animal groups, with approximately half of the species globally threatened (International Union for Conservation of Nature, IUCN). Greater understanding of which species are most threatened and why is urgently needed to inform conservation efforts to save them.

In a new study led by researchers at the Department of Biology, University of Oxford, an international team examined the greatest risks to wild populations of turtles and crocodiles worldwide. The results demonstrate that the most endangered turtles and crocodile species are those that have evolved unique life strategies. These species typically carry out highly specific roles within their ecosystems that are unlikely to be taken up by other species if they disappear.

Separated at last

In the new method, laser pulses of different power (green) are combined in such a way that single excitation (blue), double excitation (red) and triple excitation (yellow) can be distinguished, for example, in biological light-harvesting complexes.
Illustration Credit: Julian Lüttig / Universität Würzburg

Scientists at the Universities of Würzburg and Ottawa have solved the decades-old problem of distinguishing between single and multiple light excitations. They present their new method in the journal Nature.

The construction of the first laser in 1960 ushered in commercial applications with light that have become an integral part of our everyday lives. At the same time, this development opened up the scientific field of laser spectroscopy – a technique that is central to the analysis of materials and the study of fundamental physical phenomena.

Despite all the successes, however, research teams have struggled since the 1970s with the problem that a laser shining on a sample can excite it not just once, but several times per experiment. In this case, the measurement results of the single excitation and the multiple excitations overlap and usually cannot be separated, making it difficult to understand the material.

Climate change threatens lemurs on Madagascar

A female grey mouse lemur (Microcebus murinus) carrying an infant.
Photo Credit: Manfred Eberle

They are small, have a high reproductive output and live in the forests of Madagascar. During the 5-month rainy season, offspring are born and a fat pad is created to survive the cool dry season when food is scarce. But what happens when the rainy season becomes drier and the dry season warmer? Can mouse lemurs adapt to climate change thanks to their high reproductive output? Researchers from the German Primate Center – Leibniz Institute for Primate Research, together with colleagues from the University of Zurich, have analyzed long-term data from Madagascar and found that climate change is destabilizing mouse lemur populations and increasing their risk of extinction. The fact that climate change is leading to greater fluctuations in population density and thus increases extinction risk in a fast-paced, ecological generalist is an alarming warning signal for potential biodiversity losses in the tropics.

Effects of climate change have mostly been studied in large, long-lived species with low reproductive output. Small mammals with high reproductive rates can usually adapt well to changing environmental conditions, so they have been studied little in the context of climate change. Claudia Fichtel and Peter Kappeler from the German Primate Center – Leibniz Institute for Primate Research (DPZ) have been researching lemurs on Madagascar for many years and have thus built up a unique data set to fill this knowledge gap.

Adipose tissue as a culprit: How obesity leads to diabetes

A high-fat diet leads to obesity and the development of diabetes.
Photo Credit: Muffin Creatives

A research team at the University of Basel has discovered that a high-fat diet alters the function of adipose tissue, thus impairing its ability to regulate blood sugar. This explains why a high-fat diet poses a significant health risk, particularly for diabetes.

Diabetes is a medical condition in which the body is unable to keep blood sugar in a healthy range. Normally, the pancreas produces sufficient insulin to regulate the blood sugar level and maintain homeostasis. However, in diabetics, the body has lost this ability, leading to hyperglycemia.

Blood sugar levels that are persistently too high can cause long-term damage to blood vessels and lead to severe complications such as blindness or kidney failure. It has been known for some time that obese patients are particularly at risk of developing type 2 diabetes and that adipose tissue plays a critical role in the onset of the disease. In their recent study, researchers led by Professor Michael N. Hall at the Biozentrum, University of Basel, revealed how a high-fat diet triggers diabetes.

Electricity from Air

Graphic illustration of titanium-air battery properties, in the style of the periodic table of elements
Illustration Credit: Courtesy of Technion – Israel Institute of Technology

Scientists at Forschungszentrum Jülich have developed and successfully lab-tested a novel titanium-air battery in cooperation with researchers at the Technion – Israel Institute of Technology in Haifa. This is the first time that experimental results of such a battery have been published, in which titanium is used as an active material. The metal is of interest as an electricity storage material because each atom can donate up to four electrons for charge transfer, while at the same time being relatively light and extremely resistant.

Scientific Results

Titanium is known as a passive, stable material. The researchers succeeded in utilizing its electrochemical potential for the storage of electrical energy by applying an ionic liquid called EMIm(HF)2.3F. Ionic liquids consist of salts with an atypical, very low melting point, which are used in a variety of applications due to their special electrical and material properties.

Early study shows cones in retinal degeneration, thought to be dormant, may retain visual function

“While the sensitivity of the cones was about 100-1000 fold less than normal, we were surprised to find that that the drop-off in sensitivity for the ganglion cells that project to the brain was much less,” said senior author Alapakkam Sampath.
Photo Credit: Miranda Scalabrino

New UCLA research in mice suggests that “dormant” cone photoreceptors in the degenerating retina are not dormant at all, but continue to function, producing responses to light and driving retinal activity for vision.  

The cells in the retina that produce the visual experience are rods and cones. Rods are active in dim light and cones in daylight. Mutations in rods that cause them to die trigger most inherited retinal degeneration. Cones can remain alive after nearly all the rods die, but they retract key parts of the cells and appear “dormant.”  

But while past literature suggested that dormant cells were not functional, and earlier attempts to record from them revealed no light-driven activity, the new study indicates for the first time that the cells are still viable. Furthermore, downstream signals recorded from the retina show that visual processing is not as compromised as may be expected. The authors say their findings demonstrate that therapeutic interventions to protect these cells, or enhance their sensitivity, have the capability to preserve nearly normal daytime vision. 

New Study Reveals Potential Link Between Two of Astronomy’s Most Mysterious Phenomena

Artist's conception of fast radio burst reaching Earth.
Illustration Credit: Jingchuan Yu, Beijing Planetarium

International team of scientists reports a possible correlation between gravitational waves from neutron star mergers and fast radio bursts; results could improve understanding of how some deep-space bursts occur.

The secrets of deep space may be starting to reveal themselves, as rapid advances in technology and stronger research collaborations are making it possible for astronomers to piece together cosmological clues like never before.

  In the March 27 issue of the journal Nature Astronomy, an international team of scientists shows for the first time a possible relationship between neutron star mergers and fast radio bursts (FRBs) – two of the most mysterious cosmological phenomena studied over the past two decades.

  The team, which includes researchers from UNLV, University of Western Australia (UWA), and Curtin University, reports on the observation of a deep space neutron star merger followed just 2 ½ hours later by an observed FRB. If confirmed, the correlation between the two events could unlock part of the mystery of how FRBs are generated.

  Fast radio bursts (FRBs) are millisecond-long pulses of electromagnetic radio waves that occur in deep space and produce the energy equivalent to the sun’s annual output. Most FRBs occur as one-off events, while others present as repeating bursts. Though their origins are still a bit of a mystery, the fraction of FRBs emitted as repeated bursts are likely produced by highly magnetized neutron stars known as magnetars.

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