Tag Archives: mutation

Tiefere Einblicke in die Entstehung von Algengiften

Besonders im Sommer kommt es oft zur Ausbreitung von Blaualgen in heimischen Seen. Dadurch kann es auch zu einer Häufung an schädlichen Giftstoffen kommen. Wissenschaftler des Forschungsinstituts für Limnologie am Mondsee haben nun jene Gene, die die Verbreitung der Giftbildung anregen, identifiziert und die Ergebnisse in einem Fachjournal veröffentlicht.

Algen sind mikroskopisch kleine, pflanzliche Organismen, die in allen Gewässern der Erde vorkommen. Durch Nährstoffreichtum kann es im Sommer zur Massenentwicklung von Blaualgen in Gewässern kommen. Blaualgen sind genau genommen zur Photosynthese fähige Bakterien, sogenannte Cyanobakterien; die durch diese Bakterien entstehenden, meist grünlich-blauen Schlieren werden als Algen- oder Wasserblüten bezeichnet. Dabei kann es zu einer Anhäufung von Giftstoffen im Gewässer kommen, vor allem, wenn sich die Cyanobakterien explosionsartig vermehren. Diese gefährliche Wirkung für das gesamte Nahrungsnetz trifft am Ende auch den Menschen. Aber auch geringe Konzentrationen von Giftstoffen, wie z.B. das Lebertoxin Microcystin, können, bei Einnahme über einen längeren Zeitraum, die Erbsubstanz des Menschen schädigen und zu Tumoren führen. Die dadurch entstehenden direkten (etwa zur Wasseraufbereitung) und indirekten Kosten (zum Beispiel zur Ursachenbekämpfung) belaufen sich jährlich auf viele Millionen Euro. (more…)

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How a Shape-shifting DNA-repair Machine Fights Cancer

Berkeley Lab’s Advanced Light Source reveals inner-workings of essential protein found throughout life.

Maybe you’ve seen the movies or played with toy Transformers, those shape-shifting machines that morph in response to whatever challenge they face. It turns out that DNA-repair machines in your cells use a similar approach to fight cancer and other diseases, according to research led by scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).

As reported in a pair of new studies, the scientists gained new insights into how a protein complex called Mre11-Rad50 reshapes itself to take on different DNA-repair tasks. (more…)

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„Molekularer Schalter“ bei Parkinson-Protein entdeckt

Bei einer Variante von Parkinson spielt das Enzym LRRK2 eine zentrale Rolle. Wissenschaftler der Universität Kassel haben nun einen Mechanismus entdeckt, der die Aktivität von LRRK2 steuert. Das eröffnet neue Ansatzpunkte für die Entwicklung von Medikamenten gegen die bislang unheilbare Krankheit.

Parkinson ist nach Alzheimer die häufigste neurodegenerative Krankheit; Schätzungen gehen von rund sieben Millionen Erkrankten weltweit aus. Ein Teil der Erkrankungen ist erblich bedingt und wird durch Mutationen bestimmter Gene hervorgerufen. Diese sogenannte familiäre Parkinson-Variante tritt in verschieden Volksgruppen unterschiedlich häufig auf; bestimmte Mutationen sind insbesondere in Italien und Spanien verbreitet. Mutationen eines Proteins namens LRRK2 gelten als häufigste Ursache für vererbbares Parkinson. (more…)

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‘Life as Research Scientist’: Kiwamu Tanaka, Plant Biologist

Dr. Kiwamu Tanaka, an aspiring scientist, is currently doing research on Role of extracellular ATP in plant growth and development at the Division of Plant Sciences in the University of Missouri. He completed his doctoral work at The United Graduate School of Agricultural Sciences in the Kagoshima University, Japan. Recently we spoke with Dr. Tanaka to know about his research work, especially regarding the study published in Science (DOI: 10.1126/science.343.6168.290), and also about why it is important, how life as a research scientist is, and so on. So let’s hear from Dr. Tanaka:

Q. Let us start with your research topic. What is your research area? Will you please tell us a bit more on this? What did you find?

Dr. Kiwamu Tanaka: My scientific career has focused on plant-microbe interactions that can be utilized to enhance crop plant growth for agricultural purposes. Especially I had had a strong interest in biological nitrogen fixation by nodulation which is the result of a symbiosis between legume plants and special soil bacteria rhizobia. Nodulation results in the formation of a specialized organ, the nodule, where biological nitrogen fixation takes place. Given that plants cannot utilize aerial nitrogen, even though this is a primary nutrition for plants, nodulation is a great natural system by plant-microbe interaction. (more…)

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Facebook memes can evolve like genes

ANN ARBOR — What started as a politically liberal Facebook meme in support of health care reform morphed as it spread across the social network into hundreds of thousands of variations—some just a few words from the original, but others centered on taxes, beer, or Star Wars’ villain Jabba the Hutt.

The twists on the original text over time in many ways mirrored the evolution of biological genes, researchers from the University of Michigan and Facebook have found. (more…)

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Staphylococcus aureus bacteria turns immune system against itself

Around 20 percent of all humans are persistently colonized with Staphylococcus aureus bacteria, a leading cause of skin infections and one of the major sources of hospital-acquired infections, including the antibiotic-resistant strain MRSA.

University of Chicago scientists have recently discovered one of the keys to the immense success of S. aureus—the ability to hijack a primary human immune defense mechanism and use it to destroy white blood cells. The study was published Nov. 15 in Science. (more…)

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Evolution picks up hitchhikers

In a twist on “survival of the fittest,” researchers have discovered that evolution is driven not by a single beneficial mutation but rather by a group of mutations, including ones called “genetic hitchhikers” that are simply along for the ride. These hitchhikers are mutations that do not appear to have a role in contributing to an organism’s fitness and therefore its evolution, yet may play an important role down the road.

Researchers from Princeton University found in a study of 1,000 generations of adaptation in 40 yeast populations that about five to seven specific mutations, rather than just a one, are needed for an organism to succeed. The knowledge of how mutations drive evolution can inform our understanding of how tumors resist chemotherapeutics and how bacteria evolve resistance to antibiotics. The study was published July 21 in the journal Nature. (more…)

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The rhythm of everything

Dawn triggers basic biological changes in the waking human body. As the sun rises, so does heart rate, blood pressure and body temperature. The liver, the kidneys and many natural processes also begin shifting from idle into high gear. Then as daylight wanes and darkness descends, these processes likewise begin to subside, returning to their lowest levels again as we sleep.

These internal biological patterns are tightly linked to an external cosmic pattern: the earth’s rotation around the sun once every 24 hours. This endless loop of light and darkness and the corresponding synchrony of internal and external clocks, are called circadian rhythms, from “circa diem,” Latin for “approximately a day.” Circadian rhythms influence almost all living organisms, from bacteria to algae, insects, birds and, as is increasingly understood by science, humans beings. (more…)

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