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(Phys.org)—A team of researchers with Harvard University and the University of Cambridge has successfully improved the accuracy of a synthetic clock known as a repressilator. In their paper published in the journal Nature, the team describes the steps they took to reduce the amount of noise in the biological system and how well it worked. Xiaojing Gao and Michael Elowitz with the California Institute of Technology offer a News & Views piece on the work done by the team and explain how their results could improve understanding of natural gene circuits.

Scientists have noted the high precision that some living cells demonstrate in keeping track of time, such as those that are part of the circadian clock, and have tried to duplicate the process. Sixteen years ago, Michael Elowitz and Stanislas Leibler developed what is now known as the repressilator—a synthetic oscillating genetic circuit. Their results demonstrated that it was possible for genetic circuits to be designed and built in the lab. The resulting circuit functioned, but was noisy, and therefore much less accurate than natural cell clocks. In this new effort, the researchers improved several of the design of the repressilator, each greatly reducing the amount of noise, and in so doing, increased the precision.

The repressilator was made using repressor proteins that would bind to DNA sequences that were adjacent to a gene to be targeted for inhibition. Three repressors were created such that each one represented the expression of the next cycle—when the protein in one repressor increased, it caused a decrease in the expression of the second, which in turn caused an increase in expression of the third, and so on, resulting in oscillations—the actions were monitored by reporters. Unfortunately, each was bothered by random fluctuations known as noise. To reduce the noise, the researchers integrated the reporters into the repressilator, engineered the repressor proteins to degrade in order to reduce the number of copies made, and increased the binding threshold between one of the repressors and the DNA sequence.

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Last week the U.S. corporation Monsanto, which holds a leading position in the global market of genetically modified organisms (GMOs), reached a licensing agreement with the Broad Institute, Cambridge, USA, on the commercial use of the innovative genome-editing technology CRISPR/Cas9 for agriculture applications. This news has led some experts to believe that Monsanto will now completely switch from producing ‘traditional’ GMOs to ‘genetically edited’ organisms, which are supposedly ‘safer and practically identical’ to their natural alternatives.

Let’s have a closer look at this technology which makes GMO supporters feel so enthusiastic and has been positioned by them as the universal panacea solving all of mankind’s problems. We will also delve deeper into some of the darker aspects of CRISPR/Cas9; the points that biotechnology lobbyists prefer not to discuss.

crispr

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Xconomy National —

Drugs that use molecular scissors to snip out or replace defective genes. Altered mosquitoes meant to sabotage entire disease-carrying populations. Both are potential uses of genome editing, which thanks to the CRISPR-Cas9 system has spread throughout the world’s biology labs and is now on the doorstep of the outside world. But with its first applications could also come unintended consequences for human health and the environment. The U.S. Defense Advanced Research Projects Agency—a famed military R&D group—wants to finance safety measures for the new gene-editing age.

The idea for the funding program, called Safe Genes, is to get out ahead of problems that could bring the field to a screeching halt. “We should couple innovation with biosecurity,” DARPA program manager Renee Wegrzyn, said Tuesday at the SynBioBeta conference in South San Francisco. “We need new safety measures that don’t slow us down. You have brakes in your car so that you can go fast but can stop when you need to.”

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Ww.geekwire.com/2016/iot-genetics-self-driving-ships-space-travel-darpa-chief-arati-prabhakar-tours-agencys-landscape/


The Internet of Things so widely predicted as the Next Big Thing in computing is full of promise but presents a correspondingly large vulnerability to cyber attacks, said Arati Prabhakar, director of DARPA, at the 2016 GeekWire Summit in Seattle today.

IoT offers “a huge value, but then with every advance comes more attack surface,” said Prabhakar during an interview with Alan Boyle, GeekWire’s aerospace and science editor. “Provably secure embedded systems is part of the answer.”

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Crohn’s Disease is a legendarily difficult disease to not only identify but to treat or cure. The disease affects the intestines and digestive tract, stemming from bacteria in those areas building up and leading to serious side effects. It affects more than half a million people in the United States and is brutal – with the possibility of diarrhea, weight loss, fatigue, ulcers, malnutrition, and eventually colon cancer, liver disease or osteoporosis.

Treatment is limited, with the current best options being medicine to limit inflammation and prevent symptoms. There is no complete cure, only efforts to make life as comfortable and normal as possible for those afflicted. Without a specific target at which to aim some sort of treatment, the options for permanently reducing or removing symptoms and health risks are few and far between. Before now, the only thing scientists thought they knew about the disease’s cause was that E Coli was involved.

However, recent studies have led researches to believe that they have narrowed down other bacteria that contributes to the onset and ongoing symptoms of Crohn’s. Experts at the Center for Medical Mycology at Case Western Reserve and University Hospitals Cleveland Medical Center (wow, is that a mouthful!) think they have pinpointed two additional bacterial strains that contribute to the disease. They studied a cross section of people – those with the disease, those with the disease whose family members did not have it, and those without it – to attempt to identify common details in their biological tests. Such a diverse group of subjects is required not only due to the importance of adhering to the scientific method but because Crohn’s can be caused by genetics and environmental factors.

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