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Tag: "mitochondrial" at biology news

Caribbean frogs started with a single, ancient voyage on a raft from South America

... American, and South American frogs and used three mitochondrial genes and two nuclear genes in their study, building trees of relationships among the species and timing the divergences of the species with molecular-clock methods. "Molecular clocks work by counting the number of DNA-sequence mutations separating ...

Researchers identify protein pathway involved in Parkinson disease development

...utations. The Emory researchers found that the mitochondrial protein PINK1 normally protects cells from oxidati... protective TRAP1 pathway is disrupted, leading to mitochondrial damage. Other scientists recently have linked early onset Parkinson disease to mutations in both...

Ice Age extinction claimed highly carnivorous Alaskan wolves

...University in Sweden. The researchers extracted mitochondrial DNA from the fossil wolf bones preserved in permafrost and compared the sequences, called haplotypes, with those of modern-day wolves in Alaska and throughout the world. The fossils showed a wide range of haplotypes—greater in fact than their modern ...

Researchers develop marker that identifies energy-producing centers in nerve cells

...in questions, such as to what extent does neuronal mitochondrial dysfunction contribute to Parkinson's or Alzheime... possible to explore how neuronal activity and the mitochondrial energy-producing system are coordinated and how the interrelationship works. The researchers say...

Power-boosting signal in muscle declines with age

...dup in their muscle and livers and a deficiency in mitochondrial function, Shulman explained. These metabolic shift...er to maintain the same level of fat oxidation and mitochondrial biogenesis in muscle." The number of mitochondria within muscle largely determines its metabolic ...

'Marathon mice' elucidate little-known muscle type

...wild-type controls," indicative of their increased mitochondrial content, the researchers now report. Upon further examination, the researchers were surprised to find that the fibers showed a reduction in I, IIA, and IIB MHCs and as much as a 5-fold increase in IIX MHC. Nearly 100% of muscle fibers in the tran...

How appetite-stimulating brain cells work overtime during fasting

...r thermogenesis, in brown fat is the activation of mitochondrial uncoupling protein 1 (UCP1) by T3, the researchers...g-induced, T3-mediated UCP2 activation resulted in mitochondrial proliferation in the neurons, an event that was critical for the brain cells' increased excitability...

Misclassified for centuries, medicinal leeches found to be 3 distinct species

...ed species. Siddall and his colleagues examined mitochondrial and nuclear DNA of wild leeches from across their range in Europe, as well as from samples supplied by commercial providers and university laboratories that use leeches as model organisms. Their analysis clearly showed that the commercial and labo...

Molecular differences between early and advanced melanomas could provide new drug targets

... stress caused by Akt overexpression, but that the mitochondrial mutations were not essential for the aggressive growth of melanomas induced by Akt. "Our research shows that Akt overexpression on its own is sufficient to transform radial growth melanoma cells into highly invasive tumors via reactive oxygen pat...

Protein sensor for fatty acid buildup in mitochondria

...nation of why the absence of this enzyme can cause mitochondrial malfunction." Rock is a co-author of the PNAS paper. The researchers showed that PanK2, is suppressed by CoA—the molecule this enzyme triggers the cell to make. CoA normally binds tightly to PanK2, shutting it down. When a buildup of fatty acids ...

Hofmeyr skull supports the 'Out of Africa' theory

...number of genetic studies (especially those on the mitochondrial DNA) of living people indicate that modern humans evolved in sub-Saharan Africa and then left between 65,000 and 25,000 years ago to colonize the Old World. However, other genetic studies (generally on nuclear DNA) argue against this African origin a...

Researchers find hepatitis A and hepatitis C attack same protein to block immune defenses

...es. "This identifies the protein ?called MAVS, for mitochondrial antiviral signaling protein ?as extremely important for the survival of any virus in the liver." MAVS proteins project from tiny structures called mitochondria, which are found in large numbers in each liver cell. When specialized receptor molecul...

DNA analysis reveals rapid population shift among Pleistocene cave bears

...ny. Twenty of the teeth ultimately provided useful mitochondrial DNA sequence (mitochondrial DNA is especially useful for tracking population changes). The findings indicated that while four sequence types (known as haplotypes) corresponded to bears 28,000 to 38,000 years old, a fifth DNA haplotype was found only ...

Mitochondrial genes move to the nucleus -- but it's not for the sex

Why mitochondrial genes ditch their cushy haploid environs to take u...inating species. So what, exactly, might be luring mitochondrial genes to the nucleus? "We're not quite sure why yet, but we've hypothesized that successful mito...

Bacterial response to oxidation studied as toxin barometer

...ements and seeing correlations of GGKE response to mitochondrial damage in cell cultures. “If we can create a library of cellular response, we might have either a generic or a specific predictor,?said Brian Love, professor of materials science and engineering at Virginia Tech. “We don’t know yet because we have...

Rising ocean temperatures, pollution have oysters in hot water

...ry activity, the animal's blood oxygen content and mitochondrial function. The 28°C cadmium-exposed group spent more time in respiratory activity, trying to take in oxygen. Their shells were open significantly longer than any of the other groups, a measure of the amount of time they spend "breathing." (When oys...

Genetic study of Neanderthal DNA reveals early split between humans and Neanderthals

...of the Max Planck Institute, sequenced Neanderthal mitochondrial DNA in 1997 and first suggested that Neanderthals did not make a substantial contribution to the modern human gene pool. This new study, headed up by Edward Rubin of the Lawrence Berkeley National Laboratory, reinforces that long-debated theory. "W...

Few clues about African ancestry to be found in mitochondrial DNA

...gy reveals that fewer than 10% of African American mitochondrial DNA sequences analysed can be matched to mitochondrial DNA from one single African ethnic group. There has been a growing interest in the use of mitochondr...

History-hunting geneticists can still follow familiar trail

...the approach, which involves tracking sequences of mitochondrial DNA, also known as mtDNA. "The study of mtDNA h...called "natural selection," preferentially affects mitochondrial diversity, making mtDNA less useful for population size estimates. "From a conservation perspecti...

Viral marker of human migration suspect

...constructed history of human populations, based on mitochondrial DNA. "If the virus had been with humans since we were a single population, and we have almost strictly transmitted it to our children, you may expect that as populations became isolated, the virus lineages diverged as well," Shackelton noted. ...

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