Investigators from the laboratory of Ali Shilatifard, Ph.D., the Robert Francis Furchgott Professor and chair of Biochemistry and Molecular Genetics, have discovered a new repeat gene cluster sequence that is exclusively expressed in humans and non-human primates.
The discovery, detailed in a study published in Science Advances, is a breakthrough for human genome biology and has wide-ranging implications for future research in transcriptional regulation, human evolution, and the study of repetitive DNA sequences, according to the authors.
“This is an unbelievable discovery of the first elongation factor that is repeated within the human genome and is very primate-specific,” said Shilatifard, who is also director of the Simpson Querrey Institute for Epigenetics and a professor of Pediatrics.
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My name is Artem, I’m a computational neuroscience student and researcher. In this video we discuss engrams – fundamental units of memory in the brain. We explore what engrams are, how memory is allocated, where it is stored, and how different memories become linked with each other.
OUTLINE: 00:00 — Introduction. 00:39 — Historical background. 01:44 — Fear conditioning paradigm. 03:38 — Immediate-early genes as memory markers. 08:13 — Engrams are necessary and sufficient for recall. 10:16 — Excitabiliy and memory allocation. 16:19 — Brain-wide engrams. 18:12 — Linking memories together. 24:20 — Summary. 25:33 — Brilliant. 27:09 — Outro.
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The groundbreaking gene-editing technology known as Crispr, which acts like a molecular pair of scissors that can be used to cut and modify a DNA sequence, has moved rather quickly from the pages of scientific journals to the medical setting. Earlier this month, about three years after Jennifer Doudna and Emmanuelle Charpentier won the Nobel Prize in Chemistry for describing how bacteria’s immune system could be used as a tool to edit genes, regulators in the U.K. approved the first Crispr-based treatment for sickle cell disease and beta-thalassemia patients. The treatment, from Vertex Pharmaceuticals and Crispr Therapeutics, could be approved by the U.S. Food and Drug Administration early next month for sickle cell patients.
While many obstacles lie ahead for the nascent field, such as how to pay for treatments that typically cost more than $1 million, these regulatory approvals are just the start as newer gene-editing technologies such as base and prime editing make their way through human studies. In an interview, Prof. Doudna says the approval is “a turning point in medicine because it really shows how genome editing can be used as a one-and-done cure for disease.”
Gene editing is part of a broader therapeutic revolution that encompasses genetic and cellular medicine. The pills and injections we are all familiar with generally target proteins or pathways in the body to treat disease. With gene and cell therapy, we can now target the root cause of disease, sometimes curing patients.
A research team from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences (CAS) has developed an analysis service platform called CRISPRimmunity, which was an interactive web server for identifying important molecular events related to CRISPR and regulators of genome editing systems. The study is published in Nucleic Acids Research.
The new CRISPRimmunity platform was designed for integrated analysis and prediction of CRISPR-Cas and anti-CRISPR systems. It includes customized databases with annotations for known anti-CRISPR proteins, anti-CRISPR-associated proteins, class II CRISPR-Cas systems, CRISPR array types, HTH structural domains and mobile genetic elements. These resources allow the study of molecular events in the co-evolution of CRISPR-Cas and anti-CRISPR systems.
To improve prediction accuracy, the researchers used strategies such as homology analysis, association analysis and self-targeting in prophage regions to predict anti-CRISPR proteins. When tested on data from 99 experimentally validated Acrs and 676 non-Acrs, CRISPRimmunity achieved an accuracy of 0.997 for anti-CRISPR protein prediction.
Cell toxicity and genomic instability are potential side effects from the use of CRISPR-Cas9. The gene editing tool can also cause large rearrangements of DNA through retrotransposition to theoretically trigger tumor development.
While rare, the fact that CRISPR is used to edit millions of cells for some therapies means precautionary steps are warranted given the potential increase in cancer risk. However, retrotransposition is much rarer during base editing, a more precise technique that chemically changes just one “letter” of the genetic code without causing a double-strand break in DNA.
Although MHRA decided that the benefits of Casgevy outweigh its risks, the U.K. regulator granted a one-year conditional marketing authorization of the world-first gene therapy based on the findings of two global clinical trials, noting that no significant safety concerns were identified during the trials.
An algorithm that can analyse hundreds of millions of genetic sequences has identified DNA-cutting genes and enzymes that are extremely rare in nature.
Human chromosomes are long polymer chains that store genetic information. The nucleus of each cell contains the entire human genome (DNA) encoded on 46 chromosomes with a total length of about 2 meters. To fit into the microscopic cell nucleus and at the same time provide constant access to genetic information, chromosomes are folded in the nucleus in a special, predetermined way. DNA folding is an urgent task at the intersection of polymer physics and systems biology.
A few years ago, as one of the mechanisms of chromosome folding, researchers put forward a hypothesis of active extrusion of loops on chromosomes by molecular motors. Although the ability of motors to extrude DNA in vitro has been demonstrated, observing loops in a living cell experimentally is a technically very difficult, almost impossible, task.
A team of scientists from Skoltech, MIT, and other leading scientific organizations in Russia and the U.S. have presented a physical model of a polymer folded into loops. The analytical solution of this model allowed scientists to reproduce the universal features of chromosome packing based on the experimental data—the image shows the peak-dip derivative curve of the contact probability.
Two Eötvös Loránd University researchers have made an exciting breakthrough in understanding how we age.
Researchers Dr. Ádám Sturm and Dr. Tibor Vellai from Eötvös Loránd University in Hungary have achieved a significant discovery in the study of aging. Their research centered on “transposable elements” (TEs) in our DNA
DNA, or deoxyribonucleic acid, is a molecule composed of two long strands of nucleotides that coil around each other to form a double helix. It is the hereditary material in humans and almost all other organisms that carries genetic instructions for development, functioning, growth, and reproduction. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).
