Contraception, evolution and the genetic maintenance of same-sex sexual behavior

A gene is a basic unit of heredity. It is a segment of DNA that codes for a specific protein or RNA molecule. Genes are responsible for passing on traits from parents to their offspring. 
Image Credit: THAVIS 3D

Evolution depends on genes being passed down through the generations via reproduction, and same-sex sexual behavior does not result in offspring.

So, why haven’t the many genes associated with same-sex sexual behavior, known as SSB-associated genes, been purged from the human genome over time? It’s a question that has perplexed scientists for decades, one that’s explored anew in a Proceedings of the National Academy of Sciences study by two University of Michigan biologists.

One possible explanation for the persistence of SSB-associated genes is that they have more than one function, a concept called pleiotropy. Perhaps SSB-associated genes are advantageous to heterosexuals in some way, helping them to have more children.

Support for this idea includes a 2021 Nature Human Behaviour study by University of Queensland biologist Brendan Zietsch and colleagues. They presented evidence that heterosexuals carrying SSB-associated genes have more sexual partners than those not carrying the genes. This could confer an evolutionary advantage, because more sexual partners could translate into more children, according to the Zietsch et al. study.

Scientists use X-ray beams to determine role of zinc in development of ovarian follicles

Elemental map of zinc measured by synchrotron-based X-ray fluorescence microscopy demonstrates the increase in total zinc content, and the differential distribution of zinc in ovarian follicles during primordial-through-secondary-stage development. The color scale bar represents the minimum and maximum zinc contents (µg/cm2). Scale bar=10 μm.
Image Credit: NIH/Yu-Ying Chen

To make a baby, first you need an egg. To have an egg, there needs to be a follicle. And in the very beginning of follicle development, there needs to be zinc.

The last of those statements represents the new findings reported recently by a team of researchers from Michigan State University, Northwestern University and the U.S. Department of Energy’s (DOE) Argonne National Laboratory. The research builds upon earlier work looking at the role of zinc in fertilization and uncovers the importance of the metal earlier in the process of ovulation.

The results were reported in a paper in the Journal of Biological Chemistry that looked at the role of zinc in follicle development. The researchers, led by Teresa Woodruff and Tom O’Halloran of Michigan State University, used the Bionanoprobe at Argonne’s Advanced Photon Source (APS) to examine zinc and other trace elements in the egg cell itself as well as surrounding somatic cells.

Insight into brain’s waste clearing system may shed light on brain diseases

The image shows a microscopic image revealing the enhanced glymphatic transport of an intranasally delivered tracer (red), achieved using ultrasound combined with microbubbles.
Image Credit: Chen lab

Like the lymphatic system in the body, the glymphatic system in the brain clears metabolic waste and distributes nutrients and other important compounds. Impairments in this system may contribute to brain diseases, such as neurodegenerative diseases and stroke.

A team of researchers in the McKelvey School of Engineering at Washington University in St. Louis has found a noninvasive and nonpharmaceutical method to influence glymphatic transport using focused ultrasound, opening the opportunity to use the method to further study brain diseases and brain function. Results of the work are published in Proceedings of the National Academy of Sciences May 15, 2023.

Hong Chen, associate professor of biomedical engineering in McKelvey Engineering and of neurological surgery in the School of Medicine, and her team, including Dezhuang (Summer) Ye, a postdoctoral research associate, and Si (Stacie) Chen, a former postdoctoral research associate, found the first direct evidence that focused ultrasound, combined with circulating microbubbles — a technique they call FUSMB — could mechanically enhance glymphatic transport in the mouse brain. 

Focused ultrasound can penetrate the scalp and skull to reach the brain and precisely target a defined region within the brain. In previous work, Chen’s team found that microbubbles injected into the bloodstream amplify the effects of the ultrasound waves on the blood vessels and generate a pumping effect, which helps with the accumulation of intranasally-delivered agents in the brain, such as drugs or gene therapy treatments.

South Africa’s desert-like interior may have been more inviting to our human ancestors

Illustration Credit: Scientific Frontline

Lining the Cape of South Africa and its southern coast are long chains of caves that nearly 200,000 years ago were surrounded by a lush landscape and plentiful food.

During a glacial phase that lasted between 195,000 to 123,000 years ago, these caves served as refuge to a group of humans that some researchers think were the only people to survive this ice age, called Marine Isotope Stage Six, or MIS6. And in this coastal region, a lot of archaeological research has taken place. Of less interest to archaeologists has been the interior of South Africa, which was thought to be an uninhabited, inhospitable place during at least two waves of ice ages, MIS3 and 2.

Now, a study has shown that the region might have been more fertile and temperate during these two glacial periods than previously thought, and that the region likely played host to human populations living around a series of paleolakes. The study, led by University of Michigan archaeologist Brian Stewart, provides a more comprehensive timeline of the age and stages of these lakes, and shows human fingerprints across the region. The research, funded by the National Geographic Society, is published in the journal PNAS.

Mast cells have an important impact on the development of chronic myeloid leukemia

Microscopic image of bone marrow from a mouse with CML showing an unusually high number of mast cells (purple).
Image Source / Credit: Sebastian Halbach

Research team at the University of Freiburg traces the origin of proinflammatory cytokines

Chronic myeloid leukemia (CML) is a type of blood cancer that arises from malignant changes in blood-forming cells of the bone marrow. It mainly occurs in older individuals and represents about 20 percent of all adult leukemia cases. A research team led by Dr. Sebastian Halbach, Melanie Langhammer and Dr. Julia Schöpf from the Institute of Molecular Medicine and Cell Research at the University of Freiburg has now demonstrated for the first time that mast cells play a crucial role in the development of CML.  Mast cells could therefore serve as an additional therapeutic target in the clinic. “It was really impressive to see that mice lacking mast cells no longer developed severe CML,” says study leader Halbach. The results were recently published in the journal Leukemia.

Significantly elevated cytokine levels

Mast cells are cells of the immune system that play a decisive role in the defense against pathogens, but also in allergies. In this context, mast cells release inflammation inducing messenger molecules, so-called proinflammatory cytokines, which are crucial for the immune response. However, proinflammatory cytokines are also frequently found in the microenvironment of tumors and are suspected of decisively promoting cancer development. Using a mouse model for CML, the scientists were able to demonstrate for the first time that cytokines in CML could indeed originate from mast cells.

Monkeypox viruses relatively stable on surfaces

Cleaning surfaces with alcohol-based disinfectant is a good protection against infection.
Photo Credit: © RUB, Marquard

The virus remains infectious on steel surfaces for up to 30 days, but can be effectively deactivated by alcoholic disinfectants.

Pockenviruses are known to remain infectious in the area for a very long time. A study by the Molecular and Medical Virology Department at the Ruhr University Bochum showed that the temperature is very important: at room temperature, it can take up to eleven days until there is no longer a reproductive monkeypox virus on a stainless-steel surface, at four degrees Celsius even up to a month. Accordingly, it is particularly important to disinfect surfaces. According to the study, alcoholic disinfectants work well against monkeypox viruses. However, hydrogen peroxide-based disinfectants are not sufficiently effective. The team reports in Journal of infectious diseases.

Weekly observation

Since 2022, the monkey pox virus has been spreading from person to person. Even if the infection is primarily due to direct physical contact, it is possible to infect yourself via contaminated surfaces, for example in the household or in hospital rooms. "Pockenviren is known to remain infectious in the area for a very long time," explains Dr. Toni Meister from the Department of Molecular and Medical Virology at Ruhr University. “So far we have not known the exact times for monkey pox."

Brain research with organoids

Section of an electroporated brain organoid of a common marmoset. Green: electroporated cells that glow green due to the green fluorescent protein; magenta: neurons; gray: nuclei.
Photo Credit: Lidiia Tynianskaia

Scientists at the German Primate Center develop effective method to genetically modify brain organoids

Primates are among the most intelligent creatures with distinct cognitive abilities. Their brains are relatively large in relation to their body stature and have a complex structure. However, how the brain has developed over the course of evolution and which genes are responsible for the high cognitive abilities is still largely unclear. The better our understanding of the role of genes in brain development, the more likely it will be that we will be able to develop treatments for serious brain diseases. 

Researchers are approaching these questions by knocking out or activating individual genes and thus drawing conclusions about their role in brain development. To avoid animal experiments as far as possible, brain organoids are used as an alternative. These three-dimensional cell structures, which are only a few millimeters in size, reflect different stages of brain development and can be genetically modified. However, such modifications are usually very complex, lengthy and costly. Researchers at the German Primate Center (DPZ) – Leibniz Institute for Primate Research in Göttingen have now succeeded in genetically manipulating brain organoids quickly and effectively. 

Deficiency causes appetite for meat

A carnivorous leaf of Triphyophyllum peltatum with glands excreting a sticky liquid to capture insect prey.
Photo Credit: Traud Winkelmann / Universität Hannover

Under certain circumstances, a rare tropical plant develops into a carnivore. A research team from the universities of Hannover and Würzburg has now deciphered the mechanism responsible for this.

Triphyophyllum peltatum is a unique plant. Native to the tropics of West Africa, the liana species is of great interest for medical and pharmaceutical research due to its constituents: In the laboratory, this show promising medically useful activities against pancreatic cancer and leukemia cells, among others, as well as against the pathogens that cause malaria and other diseases.

However, the plant species is also interesting from a botanical perspective: Triphyophyllum peltatum is the only known plant in the world that can become a carnivore under certain circumstances. Its menu then includes small insects, which it captures with the help of adhesive traps in the form of secretion drops and digests with synthesized lytic enzymes.

Sea butterfly life cycle threatened by climate change

An adult sea butterfly, a tiny free swimming sea snail.
Photo Credit: Victoria Peck – British Antarctic Survey

Shelled pteropods, commonly known as sea butterflies, are increasingly exposed to ocean changes, but some species are more vulnerable to this threat. In a new study, published this month in the journal Frontiers in Marine Science, British Antarctic Survey (BAS) scientists examining pteropod life cycles in the Southern Ocean have found that some species might be more vulnerable to this threat due to different timings of their life cycle.

Sea butterflies are tiny, free-swimming sea snails, which are an important part of the marine ecosystem. They are also vulnerable to climate change as their shells are sensitive to ocean acidification. Now, a team of researchers led by BAS has examined the life cycles of two free-swimming sea snail species. They found that one is less vulnerable to changes in the Southern Ocean than the other, which could affect the sea snails on a population level and in turn impact the marine ecosystem.

The world’s oceans absorb approximately a quarter of all carbon dioxide (CO2) emissions. During absorption, CO2 reacts with seawater and oceanic pH levels fall. This is known as ocean acidification and results in lower carbon ion concentrations. Certain ocean inhabitants use carbon ions to build and sustain their shells. Pteropods, which are important components of the marine ecosystem, are among them.

Butterflies on the decline

According to the analysis of the scientists, the orange tip (Anthocharis cardamines) is the only butterfly species in Europe for which a significant increase can be recorded.
Photo Credit: Ulrike Schäfer

Research shows that the numbers of butterflies in meadows and pastures of Europe are in a continuous decline. A new EU regulation aims to stop this trend.

Grassland butterflies will soon play an even greater role in EU nature conservation legislation. Based on the occurrences and population trends of butterflies, the member states are supposed to document the progress they have made in implementing the planned "Nature Restoration Law". The Butterfly Grassland Indicator, recently calculated for the eighth time by European foundation "Butterfly Conservation Europe", is to be used for this. This analysis, which also includes data and expertise from many volunteers in Germany - coordinated by experts from the Helmholtz Centre for Environmental Research (UFZ) in Halle - shows an urgent need for action. This is because the situation of grassland butterflies in Europe has deteriorated considerably since the first calculations in 1990.

The diagnosis sounds worrying: More than 80% of habitats in the EU are currently considered vulnerable. This has negative consequences on their functional capability and thus the services they provide for humans. In order to counter this, the European Commission has proposed a new set of rules. This "Nature Restoration Law" is one of the key elements of the EU Biodiversity Strategy 2030 to be published this May. It defines binding targets for the entire EU for the renaturation of various ecosystems. Two years after the regulation enters into force, member states must submit plans on how they intend to meet these targets. They must also document the success of their measures.

Latest research provides SwRI scientists close-up views of energetic particle jets ejected from the sun

Southwest Research Institute (SwRI) scientists observed the first close-up views of the source of jets of energetic particles expelled from the Sun. The high-resolution images of the solar event were provided by ESA and NASA Solar Orbiter, a Sun-observing satellite launched in 2020.
Image Credit: Courtesy of SwRI

Southwest Research Institute (SwRI) scientists observed the first close-ups of a source of energetic particles expelled from the Sun, viewing them from just half an astronomical unit (AU), or about 46.5 million miles. The high-resolution images of the solar event were provided by ESA’s Solar Orbiter, a Sun-observing satellite launched in 2020.

“In 2022, the Solar Orbiter detected six recurrent energetic ion injections. Particles emanated along the jets, a signature of magnetic reconnection involving field lines open to interplanetary space,” said SwRI’s Dr. Radoslav Bucik, the lead author of a new study published this month in Astronomy & Astrophysics Letters. “The Solar Orbiter frequently detects this type of activity, but this period showed very unusual elemental compositions.”

Chemists Unravel Reaction Mechanism for Clean Energy Catalyst

Dmitry Polyansky (left) and David Grills in the pulse radiolysis lab where the research was conducted. Here, Grills programs a syringe pump that delivers the catalyst to the radiolysis cell. Polyansky adjusts the radiolysis cell inside a white insulated compartment.
Photo Credit: Brookhaven National Laboratory

Hydrogen, the simplest element on Earth, is a clean fuel that could revolutionize the energy industry. Accessing hydrogen, however, is not a simple or clean process at all. Pure hydrogen is extremely rare in nature, and practical methods to produce it currently rely on fossil fuels. But if scientists find the right chemical catalyst, one that can split the hydrogen and oxygen in water molecules apart, pure hydrogen could be produced from renewable energy sources such as solar power.

Now, scientists are one step closer to finding that catalyst. Chemists at the University of Kansas and the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have unraveled the entire reaction mechanism for a key class of water-splitting catalysts. Their work was published today in Proceedings of the National Academy of Sciences.

“It’s very rare that you can get a complete understanding of a full catalytic cycle,” said Brookhaven chemist Dmitry Polyansky, a co-author of the paper. “These reactions go through many steps, some of which are very fast and cannot be easily observed.”

Sea anemone’s sweet efforts help reef ecosystems flourish

KAUST researchers have discovered how corals can thrive in nutrient-depleted oceans. Their study shows how sea anemones are able to recycle the essential nutrient Nitrogen.
Photo Credit: Morgan Bennett-Smith / King Abdullah University of Science and Technology

Tropical oceans are known for being low in nutrients, yet they support incredibly diverse and thriving reef ecosystems created by symbiotic cnidarians such as corals and anemones. This intriguing contradiction, referred to as the Darwin Paradox, has fascinated scientists ever since Charles Darwin first described it in 1842.

A group of researchers from KAUST conducted a study on sea anemones called Aiptasia. They found out that Aiptasia uses the sugar it gets from its partners to recycle waste in its body and survive in places where there are not many nutrients.

According to Guoxin Cui, a research scientist who worked on the project with Manuel Aranda, many studies in the past have tried to figure out where the limited nutrients in the ocean come from, especially nitrogen which is rare.

Guoxin Cui explains that some studies about coral have suggested that the partnership between coral and algae creates areas with lots of nutrients. But until now, researchers didn't fully understand how these organisms were able to create such large ecosystems.

Saturn’s rings younger than previously thought — just a few hundred million years

New research reveals that Saturn's rings are much younger than the planet itself.
Photo Credit: NASA/JPL/Space Science Institute.

Saturn’s rings are much younger than scientists once thought, according to new research from Indiana University Professor Emeritus of Astronomy Richard Durisen — and they are not here to stay.

For decades, there has been debate about the origin of Saturn’s icy rings. But according to two new studies from Durisen, published in Icarus, the rings are no more than a few hundred million years old — much younger than the planet itself, which formed 4.5 billion years ago. In fact, Durisen said the rings may well have formed when dinosaurs were still walking on the Earth.

Durisen and co-author Paul Estrada, a research scientist at NASA’s Ames Research Center in California’s Silicon Valley, also concluded that the rings will last only another few hundred million years at most.

“Our inescapable conclusion is that Saturn’s rings must be relatively young by astronomical standards, just a few hundred million years old,” Durisen said. “If you look at Saturn’s satellite system, there are other hints that something dramatic happened there in the last few hundred million years.”

Heat is the Top Cause of Exertion-Related Injuries and Fatalities for Laborers

This study is one of the first of its kind to evaluate exertion-related injuries and fatalities from word-related activities
Photo Credit: Jeriden Villegas

Dangers like working high above the ground or with heavy machinery are common hazards for laborers in industries like construction or excavation. But there’s another near-universal hazard for laborers – heat.

Margaret Morrissey, a postdoctoral fellow within UConn’s College of Agriculture, Health and Natural Resources and president of occupational safety for the Korey Stringer Institute, led a recently published study that found heat is the number one cause of exertion-related injuries and fatalities on U.S. work sites.

This work was recently published in the International Journal of Environmental Research and Public Health.

Using data reported to OSHA (Occupational Safety and Health Administration), the team found that of all injuries and fatalities, about 3% were exertion related. Of that 3%, a staggering 89% were related to heat stress.