The CRISPR-Cas9 system has revolutionised gene-editing, but cutting DNA isn’t all it can do. From turning gene expression on and off to fluorescently tagging particular sequences, this animation explores some of the exciting possibilities of CRISPR.
Download a poster on ‘The expanding CRISPR toolbox’ here: https://www.nature.com/posters/crisprtoolbox
Understanding the factors that control aging has been one of humanity’s endless pursuits, from the mystical fountain of youth to practical healthful regimens to prolong life expectancy.
A team of scientists at the University of California San Diego has helped decipher the dynamics that control how our cells age, and with it implications for extending human longevity. As described in a study published in the Proceedings of the National Academy of Sciences, a group led by biologist Nan Hao employed a combination of technologies in engineering, computer science and biology to analyze molecular processes that influence aging.
As cells age, damage in their DNA accumulates over time, leading to decay in normal functioning and eventually resulting in death. A natural biochemical process known as “chromatin silencing” helps protect DNA from damage. The silencing process converts specific regions of DNA from a loose, open state into a closed one, thus shielding DNA regions. Among the molecules that promote silencing is a family of proteins—broadly conserved from bacteria to humans—known as sirtuins. In recent years, chemical activators of sirtuins have received much attention and are being marketed as nutraceuticals to aid chromatin silencing in the hopes of slowing the aging process.
Continue reading “Scientists decipher mechanisms underlying the biology of aging” »
Over just a few short years the CRISPR gene-editing technique has revolutionized science, affecting everything from medicine to agriculture. Two new breakthrough studies have just been published describing dual methods that make the process more precise and efficient paving the way for scientists to safely alter DNA mutations that cause thousands of different human diseases.
CRISPR is conventionally a cut-and-paste tool allowing scientists to chop out unwanted strands of DNA and insert new genes, but a large volume of human diseases are caused by a single point mutation somewhere in a person’s DNA. Up until now scientists have not been able to simply and directly erase or rewrite these single mutations in living human cells.
Our human genome consists of 3 billion base pairs made up of chemical units referred to by the letters A, C, G and There are 50,000 known genetic mutations that are linked to disease in humans and 32,000 of these are single point mutations. Half of those single point mutations have been identified as a G-C pair that has mutated into an A-T pair.
While NASA and SpaceX figure out how to get to Mars, they’re also thinking about how the 200-day journey and life on the red planet will affect humans. Astronauts will be dealing with nasty things like muscle atrophy and bone loss, intra-cranial pressure, psychological issues, lack of resources and long-term radiation exposure. NASA and its partners are working on things like “torpor,” a type of space hibernation, and protective Mars cave dwellings with a view. To learn more, Engadget spoke with NASA scientist Laura Kerber and Spaceworks COO John Bradford at the Hello Tomorrow symposium in Paris.
“There are a lot of challenges that are preventing us from even getting there in a healthy state,” said Bradford in a keynote speech at the event. As a human-space-exploration expert, he’s been working on a way to mitigate many of those problems by putting astronauts in a “torpor state” of prolonged hypothermia. It not only reduces the human problems but helps with technical and engineering challenges, too.
On the medical side, it addresses the so-called psycho-social challenges (you can’t get depressed if you’re asleep), reduces intra-cranial pressure, opens up new approaches like electrostimulation to reduce muscle atrophy and bone loss, and even helps minimize radiation exposure.
Continue reading “Getting to and living on Mars will be hell on your body” »
Just like how letters are strung together to form words, our DNA is also strung together by letters to encode proteins. The genetic alphabet contains only 4 natural letters — A, C, G and T, which hold the blueprint for the production of proteins that make our bodies work. Now, researchers from the Institute of Bioengineering and Nanotechnology (IBN) of the Agency for Science, Technology and Research (A*STAR) have created a DNA technology with two new genetic letters that could better detect infectious diseases, such as dengue and Zika.
Genetic alphabet expansion technology is the introduction of artificial base pairs into DNA. The existing four genetic letters are naturally bound together in base pairs of A-T and G-C. These specific base pair formations are essential in DNA replication, which occurs in all living organisms. It is the process by which a DNA molecule is duplicated to produce two identical molecules.
“The expansion of the genetic alphabet is a significant scientific achievement. It sheds insights into DNA’s natural replication mechanism, which will help us to design unique DNA molecules and technologies. For example, our technology can be used to create novel diagnostics and therapeutic agents with superior efficacy,” said IBN Executive Director Professor Jackie Ying.
Scientists are altering a powerful gene-editing technology in hopes of one day fighting diseases without making permanent changes to people’s DNA.
The trick: Edit RNA instead, the messenger that carries a gene’s instructions.
“If you edit RNA, you can have a reversible therapy,” important in case of side effects, said Feng Zhang of the Broad Institute of MIT and Harvard, a gene-editing pioneer whose team reported the new twist Wednesday in the journal Science.
A research team at MIT has used synthetic biology to create a gene circuit that triggers the immune system to attack cancer when it first detects the signs of the disease.
The circuit works by only activating the immune response when two specific cancer biomarkers are detected. The new study was published in the journal Cell this week and represents an exciting step forward for synthetic biology and cancer research.
Genome editing technologies have revolutionized biomedical science, providing a fast and easy way to modify genes. However, the technique allowing scientists to carryout the most precise edits, doesn’t work in cells that are no longer dividing — which includes most neurons in the brain. This technology had limited use in brain research, until now. Research Fellow Jun Nishiyama, M.D., Ph.D., Research Scientist, Takayasu Mikuni, M.D., Ph.D., and Scientific Director, Ryohei Yasuda, Ph.D. at the Max Planck Florida Institute for Neuroscience (MPFI) have developed a new tool that, for the first time, allows precise genome editing in mature neurons, opening up vast new possibilities in neuroscience research.
This novel and powerful tool utilizes the newly discovered gene editing technology of CRISPR-Cas9, a viral defense mechanism originally found in bacteria. When placed inside a cell such as a neuron, the CRISPR-Cas9 system acts to damage DNA in a specifically targeted place. The cell then subsequently repairs this damage using predominantly two opposing methods; one being non-homologous end joining (NHEJ), which tends to be error prone, and homology directed repair (HDR), which is very precise and capable of undergoing specified gene insertions. HDR is the more desired method, allowing researchers flexibility to add, modify, or delete genes depending on the intended purpose.
Coaxing cells in the brain to preferentially make use of the HDR DNA repair mechanism has been rather challenging. HDR was originally thought to only be available as a repair route for actively proliferating cells in the body. When precursor brain cells mature into neurons, they are referred to as post-mitotic or nondividing cells, making the mature brain largely inaccessible to HDR — or so researchers previously thought. The team has now shown that it is possible for post-mitotic neurons of the brain to actively undergo HDR, terming the strategy “vSLENDR (viral mediated single-cell labeling of endogenous proteins by CRISPR-Cas9-mediated homology-directed repair).” The critical key to the success of this process is the combined use of CRISPR-Cas9 and a virus.
Researchers have developed a technique that enables gene editing on neurons — something previously thought to be impossible. This new tool will present amazing new opportunities for neuroscience research.
Technologies designed for editing the human genome are transforming biomedical science and providing us with relatively simple ways to modify and edit genes. However, precision editing has not been possible for cells that have stopped dividing, including mature neurons. This has meant that gene editing has been of limited use in neurological research — until now. Researchers at the Max Planck Florida Institute for Neuroscience (MPFI) have created a new tool that allows, for the first time ever, precise genome editing in mature neurons. This relieves previous constraints and presents amazing new opportunities for neuroscience research.
