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Category: genetics

Circa 2015 Clues of the genetic material in vultures could give rise to humans that have immunity to nearly all bacteria and viruses.

WASHINGTON WASHINGTON (Reuters) — A diet of putrid rotting flesh may not be your cup of tea, but to the cinereous vulture, found across southern Europe and Asia, it is positively delightful. This tough bird, it turns out, is genetically wired to thrive on the stuff.

Researchers on Tuesday said they have sequenced the genome of this big scavenger, also called the Eurasian black vulture, identifying genetic traits that account for a stalwart stomach and powerful immune system that let it carry on eating carrion.

They pinpointed genetic features related to gastric acid secretion that help explain this vulture’s ability to digest carcasses and other features linked to its immune system defense against microbial and viral infections from decomposing flesh.

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Why not eradicate disease for everyone?

Zolgensma – which treats spinal muscular atrophy, a rare genetic disease that damages nerve cells, leading to muscle decay – is currently the most expensive drug in the world. A one-time treatment of the life-saving drug for a young child costs US$2.1 million.

While Zolgensma’s exorbitant price is an outlier today, by the end of the decade there’ll be dozens of cell and gene therapies, costing hundreds of thousands to millions of dollars for a single dose. The Food and Drug Administration predicts that by2025it will be approving 10 to 20 cell and gene therapies every year.

I’m a biotechnology and policy expert focused on improving access to cell and gene therapies. While these forthcoming treatments have the potential to save many lives and ease much suffering, health care systems around the world aren’t equipped to handle them. Creative new payment systems will be necessary to ensure everyone has equal access to these therapies.

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We think of DNA as the vitally important molecules that carry genetic instructions for most living things, including ourselves. But not all DNA actually codes proteins; now, we’re finding more and more functions involving the non-coding DNA scientists used to think of as ‘junk’.

A new study suggests that satellite DNA – a type of non-coding DNA arranged in long, repetitive, apparently nonsensical strings of genetic material – may be the reason why different species can’t successfully breed with each other.

It appears that satellite DNA plays an essential role in keeping all of a cell’s individual chromosomes together in a single nucleus, through the work of cellular proteins.

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Mitochondrial DNA diseases are common neurological conditions caused by mutations in the mitochondrial genome or nuclear genes responsible for its maintenance. Current treatments for these disorders are focused on the management of the symptoms, rather than the correction of biochemical defects caused by the mutation. Now, scientists at Kyoto University’s Institute for Integrated Cell-Material Science (iCeMS) in Japan report a new approach where mutant DNA sequences inside cellular mitochondria can be eliminated using a bespoke chemical compound. The approach may lead to better treatments for mitochondrial diseases.

Their findings are published in the journal Cell Chemical Biology in a paper titled, “Targeted elimination of mutated mitochondrial DNA by a multi-functional conjugate capable of sequence-specific adenine alkylation.”

“Mutations in mitochondrial DNA (mtDNA) cause mitochondrial diseases, characterized by abnormal mitochondrial function,” the researchers wrote. “Although eliminating mutated mtDNA has potential to cure mitochondrial diseases, no chemical-based drugs in clinical trials are capable of selective modulation of mtDNA mutations. Here, we construct a class of compounds encompassing pyrrole-imidazole polyamides (PIPs), mitochondria-penetrating peptide, and chlorambucil, an adenine-specific DNA-alkylating reagent.”

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As work in real and model embryos movesforward, scientists are keen to know how similar the two really are. Finding out how models differ in their molecular details, and how their cells behave, is the main reason researchers wish to push beyond 14 days in real embryos. “We can learn a lot from a model,” says Jesse Veenvliet, a developmental biologist at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany. “But it’s important to know where it goes wrong.”

Researchers are now permitted to grow human embryos in the lab for longer than 14 days. Here’s what they could learn.

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As the middle child of the “DNA to RNA to protein” central dogma, RNA didn’t get much press until its Covid-19 vaccine contribution. But the molecule is a double hero: it both carries genetic information, and—depending on its structure—can catalyze biological functions, regulate which genes are turned on, tweak your immune system, and even crazier, potentially pass down “memories” through generations.

It’s also frustratingly difficult to understand.

Similar to proteins, RNA also folds into complicated 3D structures. The difference, explain Drs. Rhiju Das and Ron Dror at Stanford University, is that we comparatively know so little about these molecules. There are 30 times as many types of RNA as there are proteins, but the number of deciphered RNA structures is less than one percent compared to proteins.

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In 2,001 Celera Genomics and the International Human Genome Sequencing Consortium published their initial drafts of the human genome, which revolutionized the field of genomics. While these drafts and the updates that followed effectively covered the euchromatic fraction of the genome, the heterochromatin and many other complex regions were left unfinished or erroneous. Addressing this remaining 8% of the genome, the Telomere-to-Telomere (T2T) Consortium has finished the first truly complete 3.055 billion base pair (bp) sequence of a human genome, representing the largest improvement to the human reference genome since its initial release. The new T2T-CHM13 reference includes gapless assemblies for all 22 autosomes plus Chromosome X, corrects numerous errors, and introduces nearly 200 million bp of novel sequence containing 2,226 paralogous gene copies, 115 of which are predicted to be protein coding. The newly completed regions include all centromeric satellite arrays and the short arms of all five acrocentric chromosomes, unlocking these complex regions of the genome to variational and functional studies for the first time.

The latest major update to the human reference genome was released by the Genome Reference Consortium (GRC) in2013and most recently patched in2019(GRCh38.p13). This assembly traces its origin to the publicly funded Human Genome Project and has been continually improved over the past two decades. Unlike the competing Celera assembly , and most modern genome projects that are also based on shotgun sequence assembly , the GRC human reference assembly is primarily based on Sanger sequencing data derived from bacterial artificial chromosome (BAC) clones that were ordered and oriented along the genome via radiation hybrid, genetic linkage, and fingerprint maps. This laborious approach resulted in what remains one of the most continuous and accurate reference genomes today. However, reliance on these technologies limited the assembly to only the euchromatic regions of the genome that could be reliably cloned into BACs, mapped, and assembled.

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A team of scientists found an unusual trick for growing bigger, heartier crops: inserting a human gene related to obesity and fat mass into plants to supersize their harvest.

Augmenting potatoes with the human gene that encodes a fat-regulating protein called FTO, which essentially alters the genetic code to rapidly mass-produce proteins, made otherwise identical potato plants grow crops that were 50 percent larger, Smithsonian Magazine reports. By growing more food without taking up more space for agriculture, the scientists say their work could help fight global hunger — without adding to its climate impact.

“It [was] really a bold and bizarre idea,” University of Chicago chemist Chuan He, coauthor of a paper published in Nature Biotechnology, told Smithsonian. “To be honest, we were probably expecting some catastrophic effects.”

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Nad plus works for alzheimers.

In June of 2,018 the World Health Organization (WHO) released the 11th edition of its International Classification of Diseases, and for the first time added aging. The classification of aging as a disease paves the way for new research into novel therapeutics to delay or reverse age-related illnesses such as cancer, cardiovascular and metabolic disease, and neurodegeneration., Nutrient sensing systems have been an intense focus of investigation, including mTOR (the mammalian target of rapamycin) for regulating protein synthesis and cell growth; AMPK (activated protein kinase) for sensing low energy states; and sirtuins, a family of seven proteins critical to DNA expression and aging, which can only function in conjunction with NAD+ (nicotinamide adenine dinucleotide), a coenzyme present in all living cells.

Across the kingdom of life, an increase in intracellular levels of NAD+ triggers shifts that enhance survival, including boosting energy production and upregulating cellular repair. In fact, the slow, ineluctable process of aging has been described as a “cascade of robustness breakdown triggered by a decrease in systemic NAD+ biosynthesis and the resultant functional defects in susceptible organs and tissues.” Aging is marked by epigenetic shifts, genomic instability, altered nutrient sensing ability, telomere attrition, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and dysregulated intercellular communication.,

By middle age, our NAD+ levels have plummeted to half that of our youth. Numerous studies have demonstrated that boosting NAD+ levels increases insulin sensitivity, reverses mitochondrial dysfunction, and extends lifespan., NAD+ levels can be increased by activating enzymes that stimulate synthesis of NAD+, by inhibiting an enzyme (CD38) that degrades NAD+, and by supplementing with NAD precursors, including nicotinamide riboside(NR) and nicotinamide mononucleotide (NMN)., A conceptual framework called NAD World, formulated over the last decade by developmental biologist Shin-ichiro Imai, MD, PhD, of Washington University School of Medicine, posits NMN as a critical, systemic signaling molecule that maintains biological robustness of the communication network supporting NAD+..

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Mutations are a part of life. Every time a virus replicates, there is a chance that its genetic code won’t be copied accurately. These typos travel inside new virus particles as they leave one body and move on to infect the next. Some of these mutations die out; others survive and circulate widely. Some mutations are harmless; others increase infectivity or allow a virus to better escape the immune system—that’s when public health bodies might deem that strain a variant of concern.

Swaps or deletions of single amino acids can change the shapes of different proteins. Mutations can happen in any of the proteins of SARS-CoV-2, and these may change the virus’s properties. Many of the worrisome mutations are found on the spike protein, as it is the target of antibody treatments and is mimicked by the currently authorized COVID-19 vaccines. Researchers are especially troubled when typos occur in two parts of the spike protein—the N-terminal domain, which is at the beginning of the protein and which some antibodies target, and the receptor-binding domain (RBD), which grabs hold of ACE2 receptors on human cells and starts the process of infection.

To understand how specific mutations affect the structure and function of the spike protein and what those changes mean for treatments and vaccines, C&EN talked to Priyamvada Acharya, Rory Henderson, and Sophie Gobeil at Duke University. With colleagues, these researchers have combined biochemical assays, cryo-electron microscopy, and modeling to show how the mutations seen in the variants of concern work together to change the stability of the spike protein. The spike is a trimer of three identical protein strands folded and interwoven together. Before the virus has infected a cell, the spike takes on two conformations: a down state, in which the RBD is hidden, and an up state, in which the RBD faces out, ready to bind to ACE2. The team found that different mutations can increase binding in different ways. This process, in which similar features are arrived at independently, is called convergent evolution.

SARS-CoV-2 variants are emerging and gaining traction around the world. What does that mean for our vaccines and treatments for COVID-19?

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