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Comment by Dr. Krishna Kumari Challa on February 12, 2025 at 8:20am

Crossing the blood–brain barrier with a payload via engineered bacteria

Researchers  have reported crossing the blood–brain barrier with help from a modified Lactobacillus plantarum. By delivering an appetite-regulating hormone directly to the olfactory epithelium, the hormone was able to reach its target.

Only the secreted hormone molecules crossed into the brain. Engineered Lactobacillus plantarum remained in the nasal passage, where it released its therapeutic payload, which then diffused along the olfactory pathway into the brain.

Current approaches to treating neurological conditions suffer from the highly protective nature of the blood–brain barrier. Intranasal therapies often encounter rapid clearance without a sustained therapeutic delivery.

In the study "Engineered Commensals for Targeted Nose-to-Brain Drug Delivery," published in Cell, researchers address these challenges by exploiting L. plantarum's natural affinity for the olfactory epithelium.
L. plantarum was chosen as a delivery vector as it naturally localizes to the olfactory epithelium binding sites. Initial investigations involved engineering L. plantarum to express and secrete hormones such as leptin, alpha-melanocyte-stimulating hormone and brain-derived neurotrophic factor (BDNF).

Experiments incorporated in vitro models using nasal cell monolayers and in vivo studies with male mice aged 6 to 8 weeks. Intranasal administration of fluorescent-labeled bacteria allowed visualization of bacterial localization.

Part 1

Comment by Dr. Krishna Kumari Challa on February 11, 2025 at 12:03pm

Mitochondria's role in diabetes

Mitochondria are essential for generating energy that fuels cells and helps them function.

Mitochondrial defects, however, are associated with the development of diseases such as type 2 diabetes. Patients who suffer from this disorder are unable to produce enough insulin or use the insulin produced by their pancreas to keep their blood sugar at normal levels.

Several studies have shown that insulin-producing pancreatic β-cells of patients with diabetes have abnormal mitochondria and are unable to generate energy. Yet, these studies were unable to explain why the cells behaved this way.

In a study published in Science, researchers used mice to show that dysfunctional mitochondria trigger a response that affects the maturation and function of β-cells.

The researchers also confirmed their findings in human pancreatic islet cells.

Mitochondrial dysfunction affects several types of cells

Their results prompted the team to expand their search into other cells that are affected during diabetes.

Reversing mitochondrial damage could help cure diabetes

Regardless of the cell type, the researchers found that damage to the mitochondria did not cause cell death.

This observation brought up the possibility that if they could reverse the damage, the cells would function normally.

To do so, they used a drug called ISRIB that blocked the stress response. They found that after four weeks, the β-cells regained their ability to control glucose levels in mice.

Losing your β-cells is the most direct path to getting type 2 diabetes. Through this study we now have an explanation for what might be happening and how we can intervene and fix the root cause.

Emily M. Walker et al, Retrograde mitochondrial signaling governs the identity and maturity of metabolic tissues, Science (2025). DOI: 10.1126/science.adf2034

Comment by Dr. Krishna Kumari Challa on February 11, 2025 at 11:50am

Nocturnal carnivores became more active during the day
The study took place at the Ongava Research Center in Namibia, a country in Southern Africa. It is a nature reserve that borders a national park, where tourists have a heavy presence.
During the dry season, animals on the reserve depend on man-made waterholes. With so few sources of water, this gave researchers a reliable spot to set up camera traps and document animal activity.

Photos were taken three days before humans came, three days while they were at the waterholes and three days after they left. Researchers did this for two years.
Four major carnivore species—the spotted hyena, black-backed jackal, brown hyena and African lion—came to the waterhole more during the day. Usually, these predators rule the night, and are less active during the day.
Having humans at the waterholes at night, when they typically aren't there, maybe threw the animals off a bit and made them nervous, say teh researchers .
Since carnivores in the area already knew humans would be around during the day, they may have felt more comfortable getting water then instead of at night when tourists usually aren't at waterholes.
Predators and prey could cross paths more often
Some herbivores also changed their schedule. The duiker, springbok, mountain zebra and plains zebra started to visit the waterholes at night, despite being more comfortable around people.

This change was likely to avoid the carnivores that started visiting the waterhole during the day. But not all herbivores made the switch.

There are many other herbivore species that are still active during the day and overlap with those carnivores now.
That can change the dynamics of the ecosystem, and some animals could get preyed upon during times of the day when they usually feel safer.
Tourism still essential for wildlife conservation
Outside of shifting schedules, the presence of humans may be stressful for some animals.

Even so, tourism remains an essential tool for bringing attention and money to wildlife conversation, the researchers said. It also offers employment and a source of income to many people, especially in rural regions.

But it also takes a very pristine environment and brings people into it.
We must understand how tourism is affecting these eco systems to protect them efficiently.

J. R. Patterson et al, Effects of human presence on African mammal waterhole attendance and temporal activity patterns, Journal of Zoology (2024). DOI: 10.1111/jzo.13245

Part 2

Comment by Dr. Krishna Kumari Challa on February 11, 2025 at 11:45am

Human presence at waterholes may change animal behavior

When tourists venture into nature, their thoughts are often focused on the animals they'll get to see. But animals may also have them in mind, according to a new study from the University of Georgia published in the Journal of Zoology.

With how common tourism is becoming, humans and animals will cross paths more often. Not only are tourists coming to watch the animals, but researchers will also stay out for long periods of time to count populations of different species.

As such, the study focused on how humans being nearby influenced the behavior of African mammals, including lions and zebras, while at waterholes.

When humans are present, some animals shift their daily activity patterns. the carnivores changed because of the human presence, and the herbivores changed because of the carnivore presence. It was not just one species that altered their behavior.

The study used a series of camera traps that took photos once animals walked by. Based on these pictures, researchers determined when and how often animals were visiting waterholes.

When humans were around, the time of day when some mammals came to the waterhole would shift compared to periods when humans weren't present. Some would visit earlier, while others visited later.

Animals shifting schedules can lead to different species interacting when they usually wouldn't—something that's especially a problem for some herbivores that could run into predators who typically aren't active during those times of the day.

Because of how important tourism is for conservation and income, the researchers emphasized the need to consider how human activity can impact animals on a larger scale.

Part 1 

Comment by Dr. Krishna Kumari Challa on February 11, 2025 at 11:41am

This work focuses on the study of the genome of the Oikopleura dioica species, a swimming organism of the marine zooplankton that belongs to the tunicates—a sister group of vertebrates—and is phylogenetically linked to evolutionary history. In this study model—a free-living tunicate or appendicularian—the team reconstructed the evolutionary history of fibroblast growth factor (FGF) gene families, which are critical in the developmental process of organisms.

"The findings suggest that the process of gene loss reduced the number of FGF growth factor gene families from eight to just two, which are the Fgf9/16/20 and Fgf11/12/13/14 families. These surviving subfamilies have doubled over the course of evolution to generate a total of 10 genes in appendicularians.
The "less, but more" evolutionary model "helps us to understand how sometimes losing opens up new possibilities for subsequent gains and, therefore, losses are necessary to favor the evolutionary origin of new adaptations

Gaspar Sánchez-Serna et al, Less, but More: New Insights From Appendicularians on Chordate Fgf Evolution and the Divergence of Tunicate Lifestyles, Molecular Biology and Evolution (2024). DOI: 10.1093/molbev/msae260

**

Part 2

Comment by Dr. Krishna Kumari Challa on February 11, 2025 at 11:39am

Less, but more: A new evolutionary scenario marked by massive gene loss and expansion

Evolution is traditionally associated with a process of increasing complexity and gaining new genes. However, the explosion of the genomic era shows that gene loss and simplification is a much more frequent process in the evolution of species than previously thought, and may favor new biological adaptations that facilitate the survival of living organisms.

This evolutionary driver, which seems counter-intuitive—"less is more" in genetic terms—now reveals a surprising dimension that responds to the new evolutionary concept of "less, but more," i.e., the phenomenon of massive gene losses followed by large expansions through gene duplications.

This is one of the main conclusions of an article published in the journal Molecular Biology and Evolution.

The paper identifies new evolutionary patterns, and it outlines a new scenario, marked by the enormous potential for genetic change and evolutionary adaptation driven by large-scale gene loss and duplication in living organisms.

Gene loss is a widespread mechanism throughout the biological scale and represents an evolutionary driving force that can generate genetic variability and also biological adaptations, and this has traditionally been known as the 'less is more' hypothesis.

Now, the paper describes a new evolutionary framework called "less, but more," which extends the previous model in terms of the importance of gene loss as an evolutionary driving force.

Part 1

Comment by Dr. Krishna Kumari Challa on February 11, 2025 at 11:33am

Students discover a new protein while investigating Streptococcus infection

Strep throat, something we've all had at some point in our lives, is caused by the bacteria Streptococcus pyogenes. Infection by Streptococcus can be fatal in serious cases and is the leading cause of death among flesh-eating diseases, resulting in over half a million deaths annually.

That scratchy, sore feeling at the back of your throat is a result of Streptococcus pyogenes infected by viruses called bacteriophages. These "phages" carry the genes for toxins that are responsible for strep throat, and when they invade Streptococcus pyogenes, they transfer these genes, enhancing the bacterium's ability to cause infection.

However, many people carry Streptococcus pyogenes on their bodies, and it doesn't make them sick. Some of the big questions in the field are when, how and why does it make you sick? And why does Streptococcus become a pathogen?

Two graduate students have discovered that phages use paratox to control the metabolism of Streptococcus, redirecting DNA processing pathways for the benefit of the phage.

With help from undergraduate student Julia Horne, the team was able to demonstrate that paratox also likely regulates when it is time for the phage to leave Streptococcus and go on to infect new bacteria. Muna and Horne now have a protein named after them, JM3 which stands for Julia Muna construct 3.

 This discovery, published in Nucleic Acids Research, has opened many doors for future research projects.

Tasneem Hassan Muna et al, The phage protein paratox is a multifunctional metabolic regulator of Streptococcus, Nucleic Acids Research (2024). DOI: 10.1093/nar/gkae1200

Comment by Dr. Krishna Kumari Challa on February 11, 2025 at 11:24am

However, glycosylation has traditionally been notoriously difficult to study. Only a small portion of proteins in the cell are glycosylated and concentrating enough of them in a sample for studying (a process called 'enriching') tends to be laborious, expensive, and time-consuming.
So far, it's not been possible to do such studies on a systematic scale, in a quantitative fashion, and with high reproducibility. These are the challenges the researchers managed to overcome with the new method.
DQGlyco uses easily available and low-cost laboratory materials, such as functionalized silica beads, to selectively enrich glycosylated proteins from biological samples, which can then be precisely identified and measured. Applying the method to brain tissue samples from mice, the researchers could identify over 150,000 glycosylated forms of proteins ('proteoforms'), an increase of over 25-fold compared to previous studies.

The quantitative nature of the new method means that researchers can compare and measure differences between samples from different tissues, cell lines, species etc. This also allows them to study the pattern of 'microheterogeneity'—the phenomenon where the same part of a protein can be modified by many (sometimes hundreds of) different sugar groups.

One of the most common examples of microheterogeneity is human blood groups, where the presence of different sugar groups on proteins in red blood cells determines blood type (A, B, O, and AB). This plays a major role in deciding the success of blood transfusions from one individual to the other.

The new method allowed the team to identify such microheterogeneity across hundreds of protein sites.
With this new weapon, teh researchers tackled the present problem.
The team found that when compared to "germ-free mice," i.e. mice grown in a sterile environment such that they completely lack any microbes in and on their body, mice colonized with different gut bacteria had different glycosylation patterns in the brain. The changed patterns were particularly apparent in proteins known to be important in neural functions, such as cognitive processing and axon growth.

The study's datasets are openly available via a new dedicated app for other researchers.

Clément M. Potel et al, Uncovering protein glycosylation dynamics and heterogeneity using deep quantitative glycoprofiling (DQGlyco), Nature Structural & Molecular Biology (2025). DOI: 10.1038/s41594-025-01485-w

Part 2

Comment by Dr. Krishna Kumari Challa on February 11, 2025 at 11:20am

Gut bacteria can alter brain proteins: New glycosylation method uncovers link

Our guts are home to trillions of bacteria, and research over the last few decades has established how essential they are to our physiology—in health and disease. A new study by researchers shows that gut bacteria can bring about profound molecular changes in one of our most critical organs—the brain.

The new study, published in the journal Nature Structural & Molecular Biology, is the first to show that bacteria living in the gut can influence how proteins in the brain are modified by carbohydrates—a process called glycosylation. The study was made possible by a new method the scientists developed—DQGlyco—which allows them to study glycosylation at a much higher scale and resolution than previous studies.

Proteins are the workhorses of our cells and their main building blocks. Sugars, or carbohydrates, on the other hand, are among the body's main sources of energy. However, the cell also uses sugars to chemically modify proteins, altering their functions. This is called glycosylation.

Glycosylation can affect how cells attach to each other (adhesion), how they move (motility), and even how they talk to one another (communication).

It is involved in the pathogenesis of several diseases, including cancer and neuronal disorders.

Part 1

Comment by Dr. Krishna Kumari Challa on February 11, 2025 at 11:09am

Helping Evolution: How humans unintentionally altered the skulls of pigs

Short snouts and a flat profile—within a span of 100 years, humans have significantly changed the shape of the skulls of German domestic pigs. According to a team of scientists , this is likely down to new breeding practices introduced at the beginning of the 20th century.

The researchers analyzed 3D scans of 135 skulls of wild boars and domestic pigs from the early 20th and 21st centuries. Surprisingly, the same effects can even be observed in species that were kept separately. Their findings have been published in the journal Royal Society Open Science.

Humans have been keeping pigs as livestock for several centuries. During this time, the animals have changed considerably. For example, they have become larger and have lost their black and brown bristles and darker skin tone.

The demand for pork in some countries increased significantly at the beginning of the 20th century and breeders were encouraged to optimize their animals. They needed them to grow quickly, provide good meat, and be fertile.

For the current study, researchers analyzed 135 skulls from three different breeds: Deutsches Edelschwein, Deutsches Landschwein—and wild boars, who acted as a control group. The skulls were either from the early 20th century or were only a few years old.

The two domestic pig breeds exhibited significant changes: The animals' snouts became significantly shorter and flatter, while the skulls of the more contemporary animals no longer had a slightly outwardly curved forehead. Researchers  didn't expect such pronounced differences to appear within a span of only 100 years.

Remarkably, both breeds of domestic pig underwent the same changes, despite being kept separately. "These changes occurred even though breeders did not select the animals specifically for their skull shape, as this trait was not important for breeding. Instead, the changes appear to be an unintended by-product of selecting the desired traits.

Another reason for the alterations could be related to changes in the animals' diet. Nutrition is known to influence the growth and development of animals. Today, pigs are mainly fed pellets that are high in protein. In contrast, the skulls of wild boars, who remain omnivores, have not undergone such changes.

The findings demonstrate how strongly humans can influence the evolution of animals.

Charles Darwin assumed that long periods of time—millions of years—are required for major changes to take place. This work is further proof that humans can greatly accelerate this process through selective breeding, say the researchers.

Creationists are you listening?

A. Haruda et al, Evolution under intensive industrial breeding: skull size and shape comparison between historic and modern pig lineages, Royal Society Open Science (2025). DOI: 10.1098/rsos.241039

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