Look deep into nature, and then you will understand everything. Albert Einstein

AGRICULTURE

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Two compounds can make MRSA vulnerable to the drugs they normally resist, showing that antibiotic resistance can be beaten

Source: MRSA superbug’s resistance to antibiotics is broken | New Scientist

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Electrical signaling was previously thought to occur only in multicellular organisms

Source: Bacteria Can Convey Electrical Messages the Same Way Neurons Do – Scientific American

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A report in the journal Science reveals how evolution harnessed viral DNA to rewire humans’ own genetic circuitry and strengthen the immune system.

Source: Study Finds Surprising Benefit of Viral DNA: Fighting Other Viruses – The New York Times

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Genetically engineered immune cells are saving the lives of cancer patients. That may be just the start.

Source: 10 Breakthrough Technologies 2016: Immune Engineering

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“Evolution, it turns out, is really good at irony.”

Source: How Viruses Infiltrated Our DNA and Supercharged Our Immune System – The Atlantic

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Why are the color blue—and plants—so absent from historical texts and cave walls?

Source: Vanished! The Surprising Things Missing From Ancient Art – Phenomena: Curiously Krulwich

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Stanford, CA— During the daytime, plants convert the Sun’s energy into sugars using photosynthesis, a complex, multi-stage biochemical process. New work from a team including Carnegie’s Mark Heinnickel, Wenqiang Yang, and Arthur Grossman identified a protein needed for assembling the photosynthetic apparatus that may help us understand the history of photosynthesis back in the early days of life on Earth, a time when oxygen was not abundant in the atmosphere. Their work is published by Proceedings of the National Academy of Sciences.

Photosynthesis takes place in stages. In the ‘first stage’ light is absorbed and used to produce energy molecules, with oxygen as a byproduct. These energy molecules are then used to power the ‘second stage’ of photosynthesis, in which carbon dioxide from the air is fixed into carbon-based sugars, such as glucose and sucrose.

Working with the green alga Chlamydomonas, the research team—which also included graduate students Rick Kim and Tyler Wittkopp of Stanford University, Karim Walters of Pennsylvania State University, and visiting professor Stephen Herbert of the University of Wyoming—focused on a protein, CGL71. It was already known to be involved in assembling the array of proteins that make up the part of the photosynthetic apparatus involved in the first stage of photosynthesis—the one that turns sunlight into the energy molecules that power the second stage and that also has an oxygen byproduct. But little about CGL71’s role in this assembly process was understood until now.

The team was able to figure out that at least one aspect of CGL71’s job is to protect the photosynthetic apparatus from oxygen during its assembly. Yes, that’s right, from oxygen. You see, photosynthesis first evolved in bacteria about 3 billion years ago, a time when the Earth’s atmosphere had very little oxygen. Of course, as photosynthetic bacteria became more and more populous on ancient Earth, the atmosphere changed, eventually creating the oxygen-rich air that we breathe today.

Oxygen is a very reactive molecule that can disrupt the iron-and-sulfur-containing clusters of proteins that are crucial to photosynthesis. Like CGL71, these clusters are critical for the first stage of photosynthesis, where they move electrons in order to create the energy molecules. Just as oxygen can rust iron that makes up a horseshoe or frying pan, it can damage the iron-and-sulfur proteins of the photosynthetic apparatus.

So as oxygen accumulated in the Earth’s atmosphere, the photosynthetic mechanism needed protection from its own byproduct, and CGL71 is one component that evolved to keep the photosynthetic apparatus stable under these new conditions.

“When we look at this critical assembly protein, CGL71, it’s as if we are looking back in time to the era when photosynthetic apparatus had to gradually adjust to the changing atmospheric conditions of our planet,” Grossman said.

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This work was supported by the National Science Foundation, Stanford Graduate Fellowships, Stanford University’s Biology Department, Carnegie’s Department of Plant Biology, the Department of Energy, The National Science Foundation and the College of Agriculture and Natural Resources and the Agricultural Experiment Station at the University of Wyoming.

 

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To protect the global food supply, scientists want to understand—and enhance—plants’ natural resistance to pathogens.

Source: Holding Their Ground | The Scientist Magazine®

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Implications profound for neurological diseases from autism to Alzheimer’s to multiple sclerosis

In a stunning discovery that overturns decades of textbook teaching, researchers at the University of Virginia (UVA) School of Medicine have determined that the brain is directly connected to the immune system by vessels previously thought not to exist. That such vessels could have escaped detection when the lymphatic system has been so thoroughly mapped throughout the body is surprising on its own, but the true significance of the discovery lies in the effects it could have on the study and treatment of neurological diseases ranging from autism to Alzheimer’s disease to multiple sclerosis.

“Instead of asking, ‘How do we study the immune response of the brain?’ ‘Why do multiple sclerosis patients have the immune attacks?’ now we can approach this mechanistically. Because the brain is like every other tissue connected to the peripheral immune system through meningeal lymphatic vessels,” said Jonathan Kipnis, PhD, professor in the UVA Department of Neuroscience and director of UVA’s Center for Brain Immunology and Glia (BIG). “It changes entirely the way we perceive the neuro-immune interaction. We always perceived it before as something esoteric that can’t be studied. But now we can ask mechanistic questions.”

“We believe that for every neurological disease that has an immune component to it, these vessels may play a major role,” Kipnis said. “Hard to imagine that these vessels would not be involved in a [neurological] disease with an immune component.”

New Discovery in Human Body

Kevin Lee, PhD, chairman of the UVA Department of Neuroscience, described his reaction to the discovery by Kipnis’ lab: “The first time these guys showed me the basic result, I just said one sentence: ‘They’ll have to change the textbooks.’ There has never been a lymphatic system for the central nervous system, and it was very clear from that first singular observation – and they’ve done many studies since then to bolster the finding – that it will fundamentally change the way people look at the central nervous system’s relationship with the immune system.”

Even Kipnis was skeptical initially. “I really did not believe there are structures in the body that we are not aware of. I thought the body was mapped,” he said. “I thought that these discoveries ended somewhere around the middle of the last century. But apparently they have not.”

‘Very Well Hidden’

The discovery was made possible by the work of Antoine Louveau, PhD, a postdoctoral fellow in Kipnis’ lab. The vessels were detected after Louveau developed a method to mount a mouse’s meninges – the membranes covering the brain – on a single slide so that they could be examined as a whole. “It was fairly easy, actually,” he said. “There was one trick: We fixed the meninges within the skullcap, so that the tissue is secured in its physiological condition, and then we dissected it. If we had done it the other way around, it wouldn’t have worked.”

After noticing vessel-like patterns in the distribution of immune cells on his slides, he tested for lymphatic vessels and there they were. The impossible existed. The soft-spoken Louveau recalled the moment: “I called Jony [Kipnis] to the microscope and I said, ‘I think we have something.'”

As to how the brain’s lymphatic vessels managed to escape notice all this time, Kipnis described them as “very well hidden” and noted that they follow a major blood vessel down into the sinuses, an area difficult to image. “It’s so close to the blood vessel, you just miss it,” he said. “If you don’t know what you’re after, you just miss it.”

“Live imaging of these vessels was crucial to demonstrate their function, and it would not be possible without collaboration with Tajie Harris,” Kipnis noted. Harris, a PhD, is an assistant professor of neuroscience and a member of the BIG center. Kipnis also saluted the “phenomenal” surgical skills of Igor Smirnov, a research associate in the Kipnis lab whose work was critical to the imaging success of the study.

Alzheimer’s, Autism, MS and Beyond

The unexpected presence of the lymphatic vessels raises a tremendous number of questions that now need answers, both about the workings of the brain and the diseases that plague it. For example, take Alzheimer’s disease. “In Alzheimer’s, there are accumulations of big protein chunks in the brain,” Kipnis said. “We think they may be accumulating in the brain because they’re not being efficiently removed by these vessels.” He noted that the vessels look different with age, so the role they play in aging is another avenue to explore. And there’s an enormous array of other neurological diseases, from autism to multiple sclerosis, that must be reconsidered in light of the presence of something science insisted did not exist.

Note: Material may have been edited for length and content. For further information, please contact the cited source.

University of Virginia, Health System

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It’s one of the big mysteries of cell biology. Why do mitochondria—the oval-shaped structures that power our cells—have their own DNA, and why have they kept it when the cell itself has plenty of its own genetic material? A new study may have found an answer.

Scientists think that mitochondria were once independent single-celled organisms until, more than a billion years ago, they were swallowed by larger cells. Instead of being digested, they settled down and developed a mutually beneficial relationship developed with their hosts that eventually enabled the rise of more complex life, like today’s plants and animals.

Over the years, the mitochondrial genome has shrunk. The nucleus now harbors the vast majority of the cell’s genetic material—even genes that help the mitochondria function. In humans, for instance, the mitochondrial genome contains just 37 genes, versus the nucleus’s 20,000-plus. Over time, most mitochondrial genes have jumped into the nucleus. But if those genes are mobile, why have mitochondria retained any genes at all, especially considering that mutations in some of those genes can cause rare but crippling diseases that gradually destroy patients’ brains, livers, hearts, and other key organs.

(more…)

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What the researchers discovered about the strategy most cells use to generate energy could be compared to the difference between generating energy by a coal plant, at left, and a nuclear power plant

 

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