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Comment by Dr. Krishna Kumari Challa on February 26, 2022 at 12:50pm

This result was critical, because it is important that any alternative to genetic modification be able to achieve the same functional outcome.

Lastly, the researchers were able to similarly silence genes specific to chloroplasts when they included a chloroplast-targeting peptide to a specific CPP-RNA complex.

Mitochondria and chloroplasts regulate much of a plant's metabolic activity. Targeting these structures with bioactive molecules delivered via spray could effectively improve economically desirable quality traits in crops. 

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Comment by Dr. Krishna Kumari Challa on February 26, 2022 at 12:49pm

Nanocarrier spray: Better crops without genetic modification

Researchers  have developed a way to improve crop quality without needing to create special genetically modified plants. Rather that changing plant genomes, the new technique relies on a spray that introduces bioactive molecules into plant cells through their leaves. The new technology could be used to help crops resist pests or become more resistant to drought—in less time and at less cost than making lines of genetically modified crops. The study was reported in the scientific journal ACS Nano.

Making transgenic plants  takes time, money, and still has not gained widespread public support. So an alternative to GM food that can overcome these problems have to be looked into. For example, rather than changing a plant's genome so that it doesn't express a particular gene, the same gene can be suppressed on the go by inserting a specific bioactive compound into the plant. In this scenario, the bioactive compound is taken into the plant's cells by a carrier that can penetrate the cell walls of plant cells.

While the concept might be simple, making it happen was a challenge. "In addition to designing a way to introduce bioactive molecules into the plants. Researchers have to consider a delivery method that would be practical for cultivated crops under real agricultural conditions. The best method would be through a spray that could be deployed over large fields relatively easily.

Many types of nanoparticles can penetrate plant cells. The researchers focused on cell-penetrating peptides (CPPs) because they can also target specific structures inside plants cells, such as chloroplasts. The first challenge was to determine which CPPs are best when using a spray. They tagged natural and synthetic CPPs with fluorescent yellow, sprayed them on plant leaves, and measured the amount of fluorescence in the leaves with a confocal laser-scanning microscope at different time points. After performing this procedure in typical laboratory Arabidopsis thaliana, as well as in several types of soybeans and tomatoes, they found several natural CPPs that were able to penetrate into the outer layer of the leaves, and in some cases even deeper.

Further experiments showed that this technique worked well when plasmid DNA was attached to the CPPs, and analysis showed that genes were effectively expressed in the leaves of both A. thaliana and soybeans after being carried into the cells through an aqueous spray. The researchers also found that by including other biomolecules and nanostructures in the spray solution, they could temporarily increase the number of pores in the leaves, which increased how much spray was taken up by the plant.

Often, crop yield can be improved by inserting or knocking out genes. After creating a transgenic plant that overexpresses yellow fluorescence in the leaves, the team attached RNA that interferes with fluorescent protein expression to a CPP. As hoped, spraying the leaves with this complex silenced yellow florescence expression.

Chonprakun Thagun et al, Non-transgenic Gene Modulation via Spray Delivery of Nucleic Acid/Peptide Complexes into Plant Nuclei and Chloroplasts, ACS Nano (2022). DOI: 10.1021/acsnano.1c07723

https://phys.org/news/2022-02-nanocarrier-crops-genetic-modificatio...

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Comment by Dr. Krishna Kumari Challa on February 26, 2022 at 12:40pm

Entering danger zones to avoid them! Planes Fly into Snowstorms to Study Snowfall

Comment by Dr. Krishna Kumari Challa on February 25, 2022 at 11:37am

Largest bacterium ever discovered

A newly discovered bacterium, Thiomargarita magnifica, challenges the definition of a microbe: its filament-like single cell is up to 2 centimetres long. T. magnifica achieves its unprecedented size by having unique cellular features: two membrane sacs. One is filled with its genetic material; the other, which is much larger, helps to keep its cellular contents pressed up against its outer cell wall so that the molecules it needs can diffuse in and out. Researchers have dubbed these sacs ‘pepins’ — inspired by the pips in fruit — and note that they blur the line between single-celled prokaryotes and eukaryotes (the group that includes humans), which pack their DNA into a nucleus.

https://www.biorxiv.org/content/10.1101/2022.02.16.480423v1.full.pd...

Comment by Dr. Krishna Kumari Challa on February 25, 2022 at 11:33am

Diseased male livers undergo sex-change

The livers of men diagnosed with hepatic diseases change sex as part of a potential self-protective mechanism, according to new research.

The surprise discovery was made during an investigation into why disruption of the body’s circadian clock is associated with obesity, type 2 diabetes and liver diseases.

When a high-fat diet was fed to mice that had their circadian clock gene turned off, researchers  expected them to develop diabetes or non-alcoholic fatty liver disease (NAFLD) like the control mice, but they didn’t! Instead they found that the liver of the obese male mice had been feminised probably due in part to the protective nature of the female sex hormone, oestrogen.

Like reproductive organs, the liver is sexually dimorphic, which means there are significant differences between the metabolic function of male and female livers.

The research team then went on to study human samples and got the same results. The more advanced the disease, the more feminisation they saw in the liver tissue.

It appears that the disruption of circadian rhythms might be protecting the liver by influencing the levels of hormones such as growth hormone, oestrogen and testosterone.

The internal body clock controls many biological functions including sleep, hormone secretion, body temperature and metabolism. This study suggests that the disruption of the circadian clock gives the body flexibility in metabolic pathways that can help to slow down disease progression.

Disruption of the circadian clock component BMAL1 elicits an endocrine adaption impacting on insulin sensitivity and liver disease, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2200083119.

Comment by Dr. Krishna Kumari Challa on February 25, 2022 at 10:53am

Drug Development and Testing - Clinical Trials 

Comment by Dr. Krishna Kumari Challa on February 25, 2022 at 9:36am

Unravelling the mysteries around type 2 diabetes

For more than 30 years, scientists have been trying to unravel the mystery of how a key biological molecule self assembles into a rogue protein-like substance known as amyloid, which is thought to play a role in the development of type 2 diabetes.

A team of scientists at the University of Leeds has, for the first time, been able to identify the step-by-step changes that take place in the molecule known as human islet amyloid polypeptide, or hIAPP, as it changes into amyloid.

They have also discovered new compounds that are able to speed up or slow down the process.

In healthy people, hIAPP is secreted by islets in the pancreas alongside the hormone insulin and it helps to regulate blood glucose levels and the amount of food in the stomach. When hIAPP malfunctions, it forms clumps of a protein-like substance called amyloid fibrils that kill the insulin-producing islets in the pancreas.

The build-up of amyloid fibrils is seen in people with type 2 diabetes although the exact mechanism of how it triggers disease is not known.

The research findings—Tuning the rate of aggregation of hIAPP into amyloid using small-molecule modulators of assembly—are published today in the journal Nature Communications.

The paper not only describes the complex molecular changes seen in hIAPP molecules as they transform into amyloid fibrils, but the scientists also announce that they have discovered two compounds, described as molecule modulators, which can control the process: one of the compounds delays it, the other accelerates it.

These molecule modulators can be used as "chemical tools" to help scientists investigate the way amyloid fibrils grow and how and why they become toxic.

Significantly they offer "starting points" for the development of drugs that could halt or control amyloid fibril formation and help in the urgent search to find ways to treat type 2 diabetes.

Understanding amyloid fibril formation is a key area of health research. The formation of fibrils is believed to be a factor in a range of life-limiting illnesses including Alzheimer's Disease and Parkinson's Disease, as well as type 2 diabetes.

Tuning the rate of aggregation of hIAPP into amyloid using small-molecule modulators of assembly, Nature Communications (2022). DOI: 10.1038/s41467-022-28660-7

https://medicalxpress.com/news/2022-02-unravelling-mysteries-diabet...

Comment by Dr. Krishna Kumari Challa on February 25, 2022 at 8:51am

The study integrated data on modern and ancient human genomes from eight different databases and included a total of 3,609 individual genome sequences from 215 populations. The ancient genomes included samples found across the world with ages ranging from 1,000s to over 100,000 years. The algorithms predicted where common ancestors must be present in the evolutionary trees to explain the patterns of genetic variation. The resulting network contained almost 27 million ancestors.

After adding location data on these sample genomes, the authors used the network to estimate where the predicted common ancestors had lived. The results successfully recaptured key events in human evolutionary history, including the migration out of Africa.

Although the genealogical map is already an extremely rich resource, the research team plans to make it even more comprehensive by continuing to incorporate genetic data as it becomes available. Because tree sequences store data in a highly efficient way, the dataset could easily accommodate millions of additional genomes.

Anthony Wilder Wohns et al, A unified genealogy of modern and ancient genomes, Science (2022). DOI: 10.1126/science.abi8264. www.science.org/doi/10.1126/science.abi8264

https://phys.org/news/2022-02-largest-human-family-tree.html?utm_so...

Part 2

Comment by Dr. Krishna Kumari Challa on February 25, 2022 at 8:51am

Researchers create largest ever human family tree

Researchers from the University of Oxford's Big Data Institute have taken a major step towards mapping the entirety of genetic relationships among humans: a single genealogy that traces the ancestry of all of us. The study has been published recently in Science.

The past two decades have seen extraordinary advancements in human genetic research, generating genomic data for hundreds of thousands of individuals, including from thousands of prehistoric people. This raises the exciting possibility of tracing the origins of human genetic diversity to produce a complete map of how individuals across the world are related to each other.

Until now, the main challenges to this vision were working out a way to combine genome sequences from many different databases and developing algorithms to handle data of this size. However, a new method published today by researchers from the University of Oxford's Big Data Institute can easily combine data from multiple sources and scale to accommodate millions of genome sequences.

This genealogy allows us to see how every person's genetic sequence relates to every other, along all the points of the genome. Since individual genomic regions are only inherited from one parent, either the mother or the father, the ancestry of each point on the genome can be thought of as a tree. The set of trees, known as a "tree sequence" or "ancestral recombination graph," links genetic regions back through time to ancestors where the genetic variation first appeared.

Part 1

Comment by Dr. Krishna Kumari Challa on February 24, 2022 at 12:20pm

Scientists Can Now Turn Stem Cells Into Bone!

 Stem cells have the superpower of turning into any other kind of cell – a superpower that some animals use to regrow limbs; for medicine, they yield the potential to help us repair parts of the human body that have been damaged by injury or disease. Carrying out those repairs requires the ability to manipulate stem cells on demand, and a new study outlines an innovative way of doing just that: by using high-frequency sound waves to turn stem cells into bone cells in as little as five days, with 10 minutes of stimulating treatment per day. Further down the line, the researchers hope this technique – which has several advantages over the processes that are in use today – could be used to regrow bone that has been lost to cancer or other types of degenerative disease.

The sound waves cut the treatment time usually required to get stem cells to begin to turn into bone cells by several days. This method also doesn't require any special 'bone-inducing' drugs and it's very easy to apply to the stem cells.

The approach builds on years of work into modifying materials with sound waves above frequencies of 10 MHz, which are much higher frequencies than researchers have previously used in these kinds of experiments. Here, a microchip was used to transform stem cells put in silicon oil and placed on a culture plate. The researchers have shown that it works with multiple types of stem cells, including fat-derived stem cells that aren't as painful to pull out of the body.

Researchers can  now use the sound waves to apply just the right amount of pressure in the right places to the stem cells, to trigger the change process.

https://onlinelibrary.wiley.com/doi/10.1002/smll.202106823

https://www.sciencealert.com/sonic-breakthrough-uses-sound-waves-to...

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