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Comment by Dr. Krishna Kumari Challa on August 3, 2022 at 9:47am

Researchers discover one of the largest known bacteria-to-animal gene transfers inside a fruit flyA fruit fly genome is not just made up of fruit fly DNA—at least for one fruit fly species. New research shows that one fruit fly species contains whole genomes of a kind of bacteria, making this finding the largest bacteria-to-animal transfer of genetic material ever discovered. The new research also sheds light on how this happens.
Scientists used new genetic long-read sequencing technology to show how genes from the bacteria Wolbachia incorporated themselves into the fly genome up to 8,000 years ago.The researchers say their findings show that unlike Darwin's finches or Mendel's peas, genetic variation isn't always small, incremental, and predictable.In addition to the long reads, the researchers validated junctions between integrated bacteria genes and the host fruit fly genome. To determine if the bacteria genes were functional and not just DNA fossils, the researchers sequenced the RNA from fruit flies specifically looking for copies of RNA that were created from templates of the inserted bacterial DNA. They showed the bacteria genes were encoded into RNA and were edited and rearranged into newly modified sequences indicating that the genetic material is functional.
An analysis of the unique sequences revealed that the bacteria DNA integrated into the fruit fly genome in the last 8,000 years—exclusively within chromosome 4—expanding the chromosome size by making up about 20 percent of chromosome 4. Whole bacterial genome integration supports a DNA-based rather than an RNA-based mechanism of integration.
They also found nearly a complete second genome and much more with almost 10 copies of some bacterial genome regions.
Wolbachia is an intracellular bacteria that infects numerous types of insects. Wolbachia transmits its genes maternally through female egg cells. Some research has showed that these infections are more mutualistic than parasitic, giving insects advantages, such as resistance to certain viruses.

Eric S. Tvedte et al, Accumulation of endosymbiont genomes in an insect autosome followed by endosymbiont replacement, Current Biology (2022). DOI: 10.1016/j.cub.2022.05.024

Comment by Dr. Krishna Kumari Challa on August 3, 2022 at 9:38am

Scientists reveal how detergents actually work
Scientists have discovered the precise way detergents break biological membranes, which could increase our understanding of how soaps work to kill viruses like COVID-19.
Detergents play a role in everyday life, from removing tough stains and cleaning messy hands to fixing sticky locks. On the nanoscale, they are extremely destructive, and only a few droplets in water can rupture and kill living organisms. This property has led to their widespread use and many soap formulations have been developed to kill disease-carrying viruses, including COVID-19.
Understanding the precise molecular-level mechanisms through which detergents work may help us better design antiviral agents that can combat disease at the earliest possible stage.
For the study, the scientists looked at the detergent Tween-20, which is a key protective ingredient in many products such as handwashes.Detergent molecules like Tween-20 are shaped like an ice cream cone. At the top of the cone is a region that interacts strongly with water, and at the bottom a group of atoms repel water and form a pointed tail. When you wash your hands with soap, an army of detergent molecules surround the bacteria and viruses on your skin, and in an attempt to escape the surrounding water, they scurry towards and bombard them, tails first, squeezing their membrane envelopes and breaking them apart.The chemical properties of detergents have been studied in detail, but until now the precise, molecular level details of the interaction have been difficult to assess because of a lack of tools and techniques capable of capturing the entire process.Researchers  have now developed a series of methods to try and learn more about these important interactions. They  created a series of highly-controllable membrane balls, and they used a molecular nanoruler known as single-molecule FRET (fluorescence resonance energy transfer), to measure how constituents of the membranes move apart during their interaction with detergents.They discovered that after Tween-20 binds to the membranes, the balls expand significantly and pores form on their surface before they completely fragment.To confirm their findings, the researchers used computer simulations to model how the membranes evolved.The experimental results from different approaches matched up extremely well, and the molecular dynamics simulations allowed scientists to extract otherwise hidden physics governing the process.
Lara Dresser et al, Tween-20 Induces the Structural Remodeling of Single Lipid Vesicles, The Journal of Physical Chemistry Letters (2022). DOI: 10.1021/acs.jpclett.2c00704

Comment by Dr. Krishna Kumari Challa on August 3, 2022 at 7:36am

Phantom vibration syndrome

What is phantom vibration syndrome?

If you feel your phone vibrating but there's no one there, you're not alone.

Ever felt your phone buzz in your pocket, then pulled it out to find no text, no call, no notification? You might be experiencing ‘phantom vibration syndrome’– and you’re not alone. According to one study, 9 out of 10 undergraduates said they had experienced the phenomenon in the last week or month.

Scientists aren’t exactly sure why these tactile hallucinations happen to so many of us. One leading theory is that our excessive smartphone use, and our creeping sense that we should be constantly available, have conditioned our brains to overinterpret sensations such as clothing moving against our skin. On the plus side, most people don’t find the phantom signals bothersome.

https://www.sciencefocus.com/science/phantom-vibration-syndrome/?ut...

Comment by Dr. Krishna Kumari Challa on July 31, 2022 at 11:42am

Why people struggle to recognise the faces of people from different racial backgrounds

Cognitive psychologists think they have discovered the answer to a 60-year-old question as to why people find it more difficult to recognize faces from visually distinct racial backgrounds than they do their own.

This phenomenon named the other-race effect (ORE) was first discovered in the 1960s and has consistently been demonstrated through the face inversion effect (FIE) paradigm, where people are tested with pictures of faces presented in their usual upright orientation and inverted upside down. Such experiments have consistently shown that the FIE is larger when individuals are presented with faces from their own race as opposed to other race faces. It has prompted decades of debate as to the underlying factors, with social scientists historically taking the view that it's indicative of how people are less motivated to engage and differentiate members of other races, thus leading to a weaker memory for them. Cognitive scientists, on the other hand, propose that it is based on the comparative lack of visual experience that people have with other-race individuals, which then results in reduced perceptual expertise with other-race faces. Now, a team in the Department of Psychology at Exeter, using direct electrical current brain stimulation, has found that the ORE would appear to be caused by a lack of cognitive visual expertise and not by social bias.

Published in the journal Scientific Reports, the research was conducted at Exeter's Washington Singer Laboratories, and used a non-invasive transcraniaL direct current stimulation (tDCS) procedure, specifically formulated to impair a person's ability to recognize upright faces. This was applied to the participants' dorsolateral prefrontal cortex, via a pair of sponges attached to their scalp.

Ciro Civile et al, Transcranial direct current stimulation (tDCS) eliminates the other-race effect (ORE) indexed by the face inversion effect for own versus other-race faces, Scientific Reports (2022). DOI: 10.1038/s41598-022-17294-w

Comment by Dr. Krishna Kumari Challa on July 31, 2022 at 11:25am

New evidence hints at the role of gut microbiota in autistic spectrum disorder

Autism spectrum disorder (ASD) is a neurological and developmental condition that affects how humans communicate, learn new things and behave. Symptoms of ASD can include difficulties in interacting with others and adapting to changes in routine, repetitive behaviors, irritability and restricted or fixated interests for specific things.

While symptoms of autism can emerge at any age, the first signs generally start to show within the first two years of a child's life. People with ASD can encounter numerous challenges, which can be addressed through support services, talk therapy and sometimes medication.

To this day, neuroscientists and medical researchers have not identified the primary causes of ASD. Nonetheless, past findings suggest that it could be caused by the interaction of specific genes with environmental factors.

Interestingly, recent neuroscience studies have found that the biological makeup of the gut could contribute to some of the most characteristic symptoms of ASD. More specifically, experiments on mice suggest that the pathway between gut bacteria  and the central nervous system can affect social behaviors.

Building on previous findings, researchers at University of Rome 'Tor Vergata' and University of Calabria have recently carried out a new study on mice, investigating the effects of transplanting fecal microbiota gathered from autistic donors to mice. Their results, published in Neuroscience, provide further evidence that links gut microbiota with social behaviors typical of ASD.

Scientists examined two different groups of mice. Mice in the first group (i.e., the experimental group) received transplanted microbiota originating from the gut of children with ASD, while mice in the other (i.e., the control group) were exposed to VPA, a synthetic compound with anticonvulsant properties, while in their mothers' wounds.

Contextually, FMT accounted for elevated expression levels of the pro-inflammatory factors IL-1β, IL-6, COX-1 and TNF-α in both brain and small intestine.

observed that the mice who received the ASD microbiota exhibited unusual behaviors while completing different maze tests that are widely used in neuroscience studies. Their behaviors could be linked to those observed in children and adults with ASD.

The recent findings gathered by this team of researchers seem to confirm previous results in the field, suggesting that gut microbiota can indeed play a role in social behaviors. In the future, they could inspire new research in this area and contribute to the testing and gradual introduction of treatments for autism that also consider diet and gut health.

Modifications of behavior and inflammation in mice following transplant with fecal microbiota from children with autism. Neuroscience(2022). DOI: 10.1016/j.neuroscience.2022.06.038.

Comment by Dr. Krishna Kumari Challa on July 31, 2022 at 9:51am

Scientists engineer DNA 'receipt book' to store cells' history

If you want to track a person's activities for a day, you could call them up every ten minutes and ask what they're doing. Easier, though, would be to provide them with a journal to log their own actions. Scientists often rely on a method akin to the first to track how cells change over time; they pick cells out of a group at set time points and take a snapshot of their genetic activity.

Now, researchers have developed a tool more like a journal or receipt book—it logs a cell's genetic activity for days at a time. The biological device, named a Retro-Cascorder, records data within strands of DNA, which can then be analyzed at any time to get the cell's activity log.

This new way of collecting molecular data gives us an unprecedented window into cells.  In addition to providing a new tool for basic research, it lets us engineer cells to be living biosensors that can record changes to their environment.

While all cells within an organism have identical genomes, they differ in which genes are turned on or off at any given time. Researchers can measure the degree to which a given gene is turned on inside a cell at different timepoints to track how the cell's behavior, function, or identity changes over time.

 wanted to engineer a system that would automatically record every time a particular gene was turned on. This would provide a more detailed look at a gene's activity pattern.

To show the utility of their new Retro-Cascorder, scientists engineered Escherichia coli (E. coli) cells to contain retrons in genes that were known to be activated in the presence of certain chemicals. They showed that, over 48 hours, a CRISPR array could accurately record the order in which these genes were turned on—and therefore the order in which the researchers added these chemicals.

"Researchers could install multiple biosensors in a cell and use them to monitor an environment over time, from a pond or wastewater facility to the inside of the human gut.

So far, researchers have only used the system to track a few genes at a time, rather than the many dozens that researchers might want to simultaneously monitor in the future. But the team is actively working on ways to expand Retro-Cascorders and adapt the system for use in cell types other than bacteria.

The paper, "Recording gene expression order in DNA by CRISPR addition of retron barcodes," was published in the journal Nature on July 27, 2022.

https://www.nature.com/articles/s41586-022-04994-6

Comment by Dr. Krishna Kumari Challa on July 31, 2022 at 9:50am

How soft sounds might dull pain in mice

Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 12:14pm

Fossil-fuel emissions hamper carbon dating

The burning of fossil fuels has officially shifted the composition of carbon isotopes in the air of the Northern Hemisphere enough to cancel out a useful signal from nuclear-weapons testing. This could cause a headache for archaeologists, because modern items now look like objects from the early twentieth century in terms of radiocarbon dating. The development means that forensic scientists will no longer be able to use radiocarbon fingerprints to pinpoint the ages of materials such as ivory, antiques and wine. “If you’re working in forensics or detecting fakes, this is a really sad moment.

Carbon dating hampered by rising fossil-fuel emissions

Archaeologists will increasingly have to rely on other techniques as emissions continue to alter the composition of carbon isotopes in air.

https://www.nature.com/articles/d41586-022-02057-4?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 11:58am

“This supports a scenario in which the market was the epicenter of the epidemic,” Worobey, a viral evolution expert, said. “With vendors getting infected first and setting off a chain of infections among community members surrounding the area.” The second study analyses SARS-CoV-2 genomic data from early cases. The researchers combined epidemic modeling with analyses of the virus's early evolution based on the earliest sampled genomes. They determined that the pandemic, which initially involved two subtly distinct lineages of SARS-CoV-2, likely arose from at least two separate infections of humans from animals at the Huanan market in November 2019 and perhaps in December 2019. The analyses also suggested that, in this period, there were many other animal-to-human transmissions of the virus at the market that failed to manifest in recorded COVID-19 cases. The authors used a technique known as molecular clock analysis, which relies on the natural pace with which genetic mutations occur over time, to establish a framework for the evolution of the SARS-CoV-2 virus lineages. They found that a scenario of a singular introduction of the virus into humans rather than multiple introductions would be inconsistent with molecular clock data. The two studies provide evidence that COVID-19 originated via jumps from animals to humans at the Huanan market, likely following transmission to those animals from coronavirus-carrying bats in the wild or on farms in China. The researchers say scientists and public officials should seek better understanding of the wildlife trade in China and elsewhere and promote more comprehensive testing of live animals sold in markets to lower the risk of future pandemics. The teams include more than 30 scholars from 20 different universities and research centers, including UCLA, the University of California San Diego, the Scripps Research Institute, the University of Arizona, and Johns Hopkins University in the U.S., among others. Part 2 ** https://researchnews.cc/news/14459/Scientists-confirm-COVID-tied-to...

Comment by Dr. Krishna Kumari Challa on July 29, 2022 at 11:57am

Scientists confirm COVID tied to wildlife sales at Chinese market

An international team of researchers has confirmed that live animals sold at the Huanan Seafood Wholesale Market were the likely source of the COVID-19 pandemic that has claimed 6.4 million lives since it began nearly three years ago.

“Rigorously combining all available evidence surrounding the emergence of SARS-CoV-2 clearly demonstrates that the virus jumped at least twice from animals to humans at the Huanan market,” said Dr. Marc Suchard, UCLA Fielding School of Public Health professor of biostatistics. “Identifying multiple transmission events finally puts to rest a single origin from elsewhere.”

Co-led by Suchard and Dr. Michael Worobey (University of Arizona), Dr. Joel Wertheim (UCSD) and Dr. Kristian Andersen (Scripps Research Institute), international teams of researchers have traced the start of the pandemic to the market in Wuhan, China, where foxes, raccoon dogs, and other live mammals susceptible to the virus were sold immediately before the pandemic began. Their findings were published Tuesday in two peer-reviewed papers in the journal Science, after being previously released in pre-print versions in February.

The publications, which have since gone through peer review and include additional analyses and conclusions, virtually eliminate alternative scenarios that have been suggested as origins of the pandemic. Moreover, the authors conclude that the first spread to humans from animals likely occurred in two separate transmission events in the Huanan market in late November 2019.

One study – “The Huanan Seafood Wholesale Market in Wuhan was the early epicenter of the COVID-19 pandemic” - scrutinized the locations of the first known COVID-19 cases, as well as swab samples taken from surfaces at various locations at the market. The other – “The molecular epidemiology of multiple zoonotic origins of SARS-CoV-2” - focused on genomic sequences of SARS-CoV-2 from samples collected from COVID-19 patients during the first weeks of the pandemic in China.

Along with Suchard, a physician who also teaches at the David Geffen School of Medicine at UCLA, UCLA post-doctoral scholars Andrew Magee and Karthik Gangavarapu co-authored this work.

The first paper examined the geographic pattern of COVID-19 cases in the first month of the outbreak, December 2019. The team was able to determine the locations of almost all of the 174 COVID-19 cases identified by the World Health Organization that month, 155 of which were in Wuhan.

Analyses showed that these cases were clustered tightly around the Huanan market, whereas later cases were dispersed widely throughout Wuhan – a city of 11 million people. Notably, the researchers found that a striking percentage of early COVID patients with no known connection to the market – meaning they neither worked there nor shopped there – turned out to live close-by.

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