Genetics of Attraction: Mate Choice in Fruit Flies

The fruit fly Drosophila melanogaster is a common model organism for studying sexual selection and evolution.
Photo Credit: Stefan Lüpold, UZH

Genetic quality or genetic compatibility? What do female fruit flies prioritize when mating? Researchers at the University of Zurich show that both factors are important at different stages of the reproductive process and that females use targeted strategies to optimize the fitness of their offspring.

Breeding female fruit flies face a difficult decision: do they mate with the male that has the best genes, or with the one whose genes best match their own? Evolutionary biologists from the University of Zurich and Concordia University have now investigated this question, because, as UZH professor Stefan Lüpold explains, “the processes underlying mate choice influence the evolution of male sexual characteristics and thus the variation within a population – not only in flies”.

Heavily mutated SARS-CoV-2 variant BA.2.86 not as resistant to antibodies as first feared

Image Credit: Fusion Medical Animation

Researchers at Karolinska Institutet who studied SARS-CoV-2 variant BA.2.86, found that the new variant was not significantly more resistant to antibodies than several other variants that are circulating. The study also showed that antibody levels to BA.2.86 were significantly higher after a wave of XBB infections compared to before, suggesting that the vaccines based on XBB should provide some cross-protection to BA.2.86.

"We engineered a spike gene that matches that of the BA.2.86 variant and tested the blood of Stockholm blood donors (specifically those donations made very recently) to see how effective their antibodies are against this new variant. We found that although BA.2.86 was quite resistant to neutralizing antibodies, it wasn't significantly more resistant than a number of other variants that are also circulating", says Daniel Sheward, lead author of the study and Postdoctoral researcher in Benjamin Murrell's team at the Department of Microbiology, Tumor and Cell Biology at Karolinska Institutet.

Dense Measurement Network Links Air Pollution and Common Agricultural Practice

Photo Credit: Yiğit KARAALİOĞLU

A group of international collaborators led by the Research Institute for Humanity and Nature (RIHN) team performed the first quantitative study of air pollution in the northwestern region of India using 29 low-cost and reliable instruments. Their study demonstrated the benefits of source region observations to link crop residue burning (CRB) and air pollution at local to regional scales.

Exposure to particulate matter less than 2.5 µm in diameter (popularly known as PM2.5) poses health hazards in cities worldwide. Although the major sources of PM2.5 are industrial, certain agricultural practices also contribute to the emission and formation of fine particles during certain seasons. CRB, a common practice in Punjab, Haryana and part of Indo-Gangetic Plain, occurs immediately after the paddy harvest in the post-monsoon period (September-November). CRB activities have increased in the past two decades partly due to rise in mechanized agriculture in the 1990s and delayed rice planting in Punjab and Haryana following the Preservation of Subsoil Water Act (2009).

Since 2010, the effects of CRB in Punjab and Haryana on the Delhi and its surrounding area (known as the national capital region - NCR) have been in the spotlight. Yet, no measurements of PM2.5 in the source regions have been conducted. To rectify this, a group of researchers conducted an intensive field campaign involving the states of Punjab, Haryana and the NCR from September 1 to November 30, 2022, using 29 Compact and Useful PM2.5 Instruments with Gas sensors (CUPI-Gs).

New material discovery could revolutionize rollout of global vaccinations

Photo Credit: RF._.studio

New raw vaccine materials that could make vaccines more accessible, sustainable, and ethical have been discovered.

Adjuvants are vaccine ingredients that boost a person’s immune response to a vaccine, providing greater protection against disease. One of the most prevalent adjuvant materials used in vaccines is squalene, which is typically sourced from shark livers.

Researchers at the University of Nottingham collaborated with the Access to Advanced Health Institute (AAHI) to identify synthetic alternatives to squalene that ensure sustainable, reliable, and ethical sourcing of adjuvant raw materials for vaccines moving forward.

New synthetic adjuvant materials were developed from commercially available methacrylate monomers, ensuring that a reliable supply of the material is continually available.

The combination of these adjuvant materials is scalable through catalytic chain transfer polymerization, a process that allows high levels of control over the molecular weight of the product polymer. Controlling the molecular weight is key to the use of adjuvant material in formulations for vaccines as it allows for purification in the manufacturing process and optimizes biological responses following immunization.

Ancient plant wax reveals how global warming affects methane in Arctic lakes

A 2014 field photo from Wax Lips Lake on northwest Greenland with the Greenland Ice Sheet in the background and three of the study authors (Jamie McFarlin, Everett Lasher, Yarrow Axford).
Photo Credit: Alex P. Taylor

By studying fossils from ancient aquatic plants, Northwestern University and University of Wyoming (UW) researchers are gaining a better understanding of how methane produced in Arctic lakes might affect — and be affected by — climate change.

In a new study, the researchers examined the waxy coatings of leaves preserved as organic molecules within sediment from the early-to-middle Holocene, a period of intense warming that occurred due to slow changes in Earth’s orbit 11,700 to 4,200 years ago. These wax biomarkers — which were once a part of common aquatic brown mosses — were preserved in sediment buried beneath four lakes in Greenland.

Monitoring changes in methane levels

By studying these biomarkers, the researchers discovered that past warming during the middle Holocene caused lakes across a wide range of Greenland’s climates to generate methane. Because methane is a more potent greenhouse gas than carbon dioxide, any changes in methane production with warming are important to understand.

New study shows signs of early creation of modern human identities

SapienCE researchers have publiched a new study which provides vital information about how and when we may have started developing modern human identities. Image showing excavation at Blombos Cave, South Africa.
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Photo Credit: UiB, SapienCE

The study, which is newly published in the Journal of Human Evolution, confirms previous scant evidence, and supports a multistep evolutionary scenario for the culturalization of the human body.

Eye-catching shells made into ornaments

The new study is conducted by Francesco d'Errico, Karen Loise van Niekerk, Lila Geis and Christopher Stuart Henshilwood. The significant findings provide vital information about how and when we may have started developing modern human identities.

“The discovery of eye-catching unmodified shells with natural holes from 100 to 73 ka confirms previous scant evidence that marine shells were collected, taken to the site and, in some cases, perhaps worn as personal ornaments before a stage in which shells belonging to selected species were systematically, and intentionally perforated with suitable techniques to create composite beadworks”, van Niekerk says.

Similar shells have been found in North Africa, other sites in South Africa and the Mediterranean Levant, which means that the argument is supported by evidence from other sites, not just Blombos Cave.

Small but mighty new gene editor

Structural analysis and deep mutational scanning (DMS) of AsCas12f. The team used cryogenic electron microscopy, a method to look at the structure of biological molecules in high-resolution, to analyze AsCas12f and engineer their new version. The DMS “heatmap” illustrates how all single mutations affected genome-editing activity. Blue squares indicate an undesirable mutation, while red ones represent desirable changes. The darker the color, the greater the effect.
Illustration Credit: © Hino et al. 2023

A new CRISPR-based gene-editing tool has been developed which could lead to better treatments for patients with genetic disorders. The tool is an enzyme, AsCas12f, which has been modified to offer the same effectiveness but at one-third the size of the Cas9 enzyme commonly used for gene editing. The compact size means that more of it can be packed into carrier viruses and delivered into living cells, making it more efficient. Researchers created a library of possible AsCas12f mutations and then combined selected ones to engineer an AsCas12f enzyme with 10 times more editing ability than the original unmutated type. This engineered AsCas12f has already been successfully tested in mice and has the potential to be used for new, more effective treatments for patients in the future.

By now you have probably heard of CRISPR, the gene-editing tool which enables researchers to replace and alter segments of DNA. Like genetic tailors, scientists have been experimenting with “snipping away” the genes that make mosquitoes malaria carriers, altering food crops to be more nutritious and delicious, and in recent years begun human trials to overcome some of the most challenging diseases and genetic disorders. The potential of CRISPR to improve our lives is so phenomenal that in 2020, researchers Jennifer Doudna and Emmanuelle Charpentier, who developed the most precise version of the tool named CRISPR-Cas9, were awarded the Nobel Prize in chemistry.

A lethal parasite’s secret weapon: infecting non-immune cells

Photomicrograph of spleen tissue showing the presence of numerous Leishmania donovani parasites in the amastigote form they take after infecting a host.
Image Credit: Centers for Disease Control and Prevention

The organisms that cause visceral leishmaniasis, a potentially deadly version of the parasitic disease that most often affects the skin to cause disfiguring disease, appear to have a secret weapon, new research suggests: They can infect non-immune cells and persist in those uncommon environments. 

Researchers found the Leishmania donovani parasites in blood-related stem cells in the bone marrow of chronically infected mice – precursor cells that can regenerate all types of cells in the blood-forming system. The finding may help explain why some people who develop visceral leishmaniasis, which is fatal if left untreated, often also have blood disorders such as anemia. 

Identifying these cells and other unexpected locations in which these parasites live improve scientists’ understanding of the disease and may lead to new treatment options, said senior study author Abhay Satoskar, professor of pathology in The Ohio State University College of Medicine. 

A new bioinfomatics pipeline solves a 50-year-old blood group puzzle

Photo Credit: Belova59

Currently, a lot is known about which genes are responsible for our individual blood groups, however not much is understood about how and why the levels of the blood group molecules differ between one person to another. This can be important for blood transfusion safety. Now a research group at Lund University in Sweden has developed a toolbox that finds the answer – and in doing so, has solved a 50-year-old mystery.

The study was published recently in Nature Communications.

For the past 30 years, the research group in Lund has studied the genetic basis of our many blood groups and their research has laid the foundation for six new blood group systems. On the surface of the red blood cell are found proteins and carbohydrates that are very similar between people.

However, small differences in these molecules have been shown to be due to genetic variants that encode what we know as blood group antigens. What has not been understood until now is why people with the same blood group can have different amounts of a certain blood group antigen on their red blood cells.

Study shows that Basophil Activation Test (BAT) is key for predicting allergic reactions

Photo Credit: Jakub Kapusnak

Researchers have found that BAT was the best biomarker to predict severity and threshold of allergic reactions to eggs

New research, published in the European Journal of Allergy and Clinical Immunology, has found that Basophil Activation Test (BAT) can be used to better detect allergies and predict the severity of allergic reactions than traditional predictions made via clinical criteria.

The MRC-funded Basophil Activation Test to Diagnose Food Allergy (BAT2) Study, led by Professor Alexandra Santos of King’s College London, aimed to identify if BAT testing could be used to predict the risk of severe allergic reactions and/or low threshold of reactivity.

For the study one hundred and fifty children, recruited from specialized tertiary Pediatric Allergy clinics in London, underwent double-blind placebo-controlled food challenge to determine possible allergies to baked egg. Patients who passed this underwent a similar process but this time with loosely cooked egg, with the severity of allergic reactions classified following Practall guidelines.