mitochondrial

The secret lives of whales

...gally sold as food, Palumbi examined variations in mitochondrial DNA from individual whales. He was amazed at their genetic variation ?an indicator of the past size of their population. Piecing together their ancient family trees, he has discovered that the Antarctic population of minke whales is now the longest s...

Mitochondrial DNA mutations play significant role in prostate cancer

Mutations in mitochondrial DNA (mtDNA) playan important role in the developme...this may be an importantcontributory factor in the mitochondrial enhancement of prostate cancertumor growth. Because the study found that COI mutations were common i...

Critical role in programmed cell death identified

... their activity in mammalian cell death was known, mitochondrial involvement in worms had not previously been shown...l now. Conradt and her colleagues determined that mitochondrial fragmentation is required for cells to die and that the process that commits cells to the point of n...

Opposing fat metabolism pathways triggered by a single gene

...c effects occurring within two metabolic pathways: mitochondrial lipid oxidation and fatty acid desaturation. Following up on these changes in gene expression, Yamamoto and colleagues show that in its normal actions, nhr-49 sets in motion two opposing pathways: it increases expression of a gene acs-2, which leads...

A human parasite with a streamlined mitochondrion

...some contains a single type of a protein, called a mitochondrial carrier, that in human mitochondria exists in many... thus it provides a model system for probing which mitochondrial functions are truly essential for eukaryotic cells. ...

The biggest family tree ever

...mosome, which is passed on from father to son, and mitochondrial DNA, which is passed on from mothers to their sons and daughters. This enables the researchers to decipher the characteristic genetic markers of both parental lineages. UA is collaborating in a joint venture with Family Tree DNA, a company specializ...

Ancient DNA helps clarify the origins of two extinct New World horse species

...re the origins of the horses, the authors examined mitochondrial DNA (mtDNA) extracted from fossilized horse bones. Mitochondria, which have their own genome, contain a stretch of sequence that's useful for inferring evolutionary relationships: though the region undergoes high mutation rates, the patterns of mutat...

Neandertal femur suggests competition with hyenas and a shift in landscape use

...ve comes from a Neandertal, based on its shape and mitochondrial DNA. Its age places it at the end of the Middle Paleolithic archeological period, just before modern humans arrived in Europe. The research will be published in the PNAS online early edition the week of May2-6. "In Europe, with the transition from ...

New protein vital for immune response is found in surprise location

...nergy required for daily life. "This is the first mitochondrial protein known to be involved in immune defense against any microbial infection," said Dr. Zhijian "James" Chen, associate professor of molecular biology at UT Southwestern and the study's senior author. "This discovery puts mitochondria on the map in...

New mitochondrial DNA gene chip may be early cancer diagnosis tool

...he measurement accuracy of new techniques that use mitochondrial DNA as an early indicator for certain types of can... laboratories of the EDRN. The lab found that full mitochondrial genome sequencing using capillary electrophoresis detected mtDNA changes associated with early cance...

Lance Armstrong through a physiological lens: hard training boosts muscle power 8%

... as reflected by a 38% increase in activity of the mitochondrial enzyme citrate synthase," Coyle noted. Mechanisms...t is plausible that a training-induced increase in mitochondrial potential, as measured by CS maximal activity, improved respiratory control sensitivity during exerc...

Elderly mice yield clues to the process of growing old

... could prevent the gathering of genetic defects in mitochondrial DNA, genetic material that resides outside of the ...store some functions such as hearing by protecting mitochondrial DNA from naturally occurring mutations. Using mice genetically altered to have a deficiency in a pr...

Researchers develop gene therapy to reverse pulmonary arterial hypertension

...y has already been tried in humans with congenital mitochondrial diseases, the team is initiating a clinical trial in human PAH. Similarly, newer drugs that inhibit Survivin, currently in trials in oncology, might also be directly applicable to PAH patients, Dr. Michelakis explains. The researchers are supported ...

Molecular trigger for Huntington's disease found

...uclear transcription factor that regulates various mitochondrial genes and insofar as mitochondrial dysfunction appears important in HD, our findings provide a molecular mechanism linking disturbances...

Protease inhibitors reach beyond HIV

...e PIs prevent programmed cell death by maintaining mitochondrial integrity. These data show that PIs block programmed cell death in vivo and that related compounds may be useful for non-HIV disorders also characterized by excessive programmed cell death. ...

Genetic link confirmed between Polynesians and indigenous Taiwanese

...ndigenous Taiwanese. Genetic techniques involving mitochondrial DNA (mtDNA) have been used to try and determine wh...JH, Lee CL, He CL, et al. (2005) Traces of archaic mitochondrial lineages persist in Austronesian-speaking Formosan populations. PLoS Biol 3(8): e247. ...

High-Throughput GoMiner

...ndigenous Taiwanese. Genetic techniques involving mitochondrial DNA (mtDNA) have been used to try and determine wh...JH, Lee CL, He CL, et al. (2005) Traces of archaic mitochondrial lineages persist in Austronesian-speaking Formosan populations. PLoS Biol 3(8): e247. ...

Tiny roundworm's telomeres help scientists to tease apart different types of aging

... of aging is the insulin signaling pathway, proper mitochondrial function and dietary restriction," he reasons. Several types of cells in our body, such as mature nerve cells in the brain, oocytes, skeletal and heart muscle cells don't actively divide but stay put just like the cells in adult worms. "That makes ...

Picky female frogs drive evolution of new species in less than 8,000 years

...rn mothers, judging by the absence of any southern mitochondrial DNA, which is contributed only by the mother. Hoskin and colleagues argue that because southern females have the most to lose in such cross-breeding, there may have been selection pressure to evolve a mating strategy to minimize dead-end mating with...

New amphibian species result from exploration, not from rule changes

...nvestigators compared the sequence of a particular mitochondrial gene in mantellid species recognized at various times from the 19th century to the present. The gene sequences were no more similar in recently recognized species than in long-recognized species, a result that argues again taxonomic inflation as the ...

Embryonic stem cells accrue genetic changes

... In addition to probing changes in the nuclear and mitochondrial DNA sequences and copy numbers, the researchers ex... batch. Two of the nine lines had changes in their mitochondrial DNA over time, and all nine stem cell lines exhibited some shift in methylation of at least one of t...

Ancient trans-Atlantic swarm brought locusts to the New World

...d legs of locusts, Lovejoy and his colleagues used mitochondrial DNA sequences to reconstruct the evolutionary history of the Schistocerca locusts. The team found that the desert locust lineage gave rise to the more than 50 Schistocerca species found in the western hemisphere. ...

Evolutionary conservation of a mechanism of longevity from worms to mammals

...ntial cofactor in numerous redox reactions such as mitochondrial respiration. Though lack of the mclk1 gene results in embryonic lethality, the authors were able to study mclk1-/- embryonic stem (ES) cells and show that they are resistant to oxidative stress and exhibit reduced DNA damage when compared to ES cell...

Scientists sequence DNA of woolly mammoth

...can and Indian elephants, not just at the level of mitochondrial sequences, but also encompassing information from ...00-fold higher copy number per cell. However, the mitochondrial genome codes for only a tiny fraction of an organism's genetic information -- 0.0006 percent in the...

Argonne researchers confirm lead in Beethoven's illness

...nt it to the University of Muenster in Germany for mitochondrial DNA comparison with the samples of Beethoven's hair, owned by the Beethoven Society and also analyzed by Walsh and his colleagues at the Advanced Photon Source. The findings confirm the earlier work done on the hair samples. In addition, the researc...

Researchers uncover mechanisms of estrogen in promoting cell death in breast cancer

...of cell mitochondria, led to depolarization of the mitochondrial membrane, and stimulated the release of a molecule called cytochrome c into the cell's interior, where it could activate several cellular enzymes, called caspases, which in turn initiate cell degradation. They also found that estradiol caused complet...

Why the Amazon rainforest is so rich in species

...t Alaine Whinnett tested the "DNA clock" using the mitochondrial DNA of nine different butterfly species groups [genera] on the eastern side of the Andes in Eastern Peru. By using a "DNA clock" the scientists were able to calculate the age of the species within each group of species. If the DNA is similar between ...

Three new species of lemurs identified

...file, called a 'karyotype', or the sequence of the mitochondrial cytochrome b gene. The team analysed the karyotypes of 99 individuals from all currently recognised species of lemur and the cytochrome b gene was sequenced in 68 individuals. From the karyotypic profiles, Andriaholinirina et al. could identify indi...

Lactic acid not athlete's poison, but an energy source - if you know how to use it

... cytoplasm, where lactate is produced, through the mitochondrial membrane into the interior of the mitochondria, wh...e enzymes that burn lactate. In fact, the cellular mitochondrial network, or reticulum, has a complex of proteins that allow the uptake and oxidation, or burning, of...

Protein translation in sperm

... during the capacitation phase. They identify that mitochondrial translation machinery (as opposed to cytoplasmic) directs translation of nuclear-encoded genes in sperm, and that its inhibition leads to a marked decrease in sperm motility, actin polymerization, the acrosome reaction and in vitro fertilization rate...

World Trade Center identifications pushed forensic DNA technology

...totyping and SNPs. Mitotyping involves looking at mitochondrial DNA, DNA inherited only from the mother, and comparing it to a standard reference. While mitochondrial DNA is not unique -- entire maternal ancestry lines share the same mtDNA -- it, along with STR, coul...

Hopkins researchers discover genetic switch that turns off an oxygen-poor cell's combustion engine

...searchers found deliberately shuts off the cell's mitochondrial combustion engine, which scientists had long - and...xygen conditions, apparently to protect cells from mitochondrial toxic oxygen pollutants," said Chi Van Dang, M.D., Ph.D., professor of medicine, cell biology, oncol...

Chocolate milk could be key to longer, healthier life

...erobic exercise can also increase the synthesis of mitochondrial proteins which affect our ability to make energy and play a large role in our mortality. "We know of course that exercise has a wide variety of health benefits, but our research specifically targets mitochondria since they are a cause of age-related...

Biomarkers may hone anti-aging therapies

...ia and decreased energetic capacity resulting from mitochondrial DNA mutations, Sligh explained. In addition, mutations in mitochondrial DNA have been associated with tumor development. "We initiated this project with the idea that perh...

First direct mechanical communication of mitochondria, cardiomyocyte nucleus shown

...cted phenomenon: various substances which increase mitochondrial size, also increased contractile force of cardiac ...," or myofibrils. This effect isn't related to the mitochondrial energy production, they noted, and so a hypothesis was developed that "there might be in cardiac cel...

Attacking cancer's sweet tooth is effective strategy against tumors

...olysis, but it was not clear if the glycolytic and mitochondrial pathways were connected in this fashion. It appe...ough the knock down of LDHA), they could lower the mitochondrial membrane potential of tumor cells. What is more, oxygen consumption increased in the knockdown cells...

Mitochondrial DNA sequencing tool updated

... the first time rapidly and reliably sequences all mitochondrial DNA. Mitochondria, the energy-producing organelle...hip will be a key tool in accelerating research on mitochondrial DNA, a growing area of scientific interest. This interest stems from data that suggests natural seq...

Computational model simulates AZT metabolism in mitochondria

...nisms to see which ones could actually lead to the mitochondrial defects found in AIDS patients." He added: "It is ...at the triphosphorylated form of AZT can enter the mitochondrial matrix, the inner core of the mitochondrion, and disrupt the replication of mitochondrial DNA by pre...

New egg freezing technique offers hope to hundreds of women

... type and amount of the damage; alterations in the mitochondrial organisation can be very subtle and deserve to be further investigated by transmission electron microscopy." Professor Arne Sunde, former chairman of ESHRE, said: "Cryopreservation of human semen and embryos has been a routine procedure since the ea...

Study details hepatitis C ability to block immune system response

...on. One of the intermediaries in that cascade is a mitochondrial antiviral signaling protein (MAVS). HCV blocks the production of type1 interferon by using its protease activity to destroy MAVS. By preventing infected cells from producing interferon, the virus inhibits the body's immune response against HCV, enabl...

Researchers attack tumor cells by exploiting dependency on sugar metabolism

...and the interplay between glycolytic phenotype and mitochondrial metabolism. The researchers used a sophisticated g...t and lung cancers. Inhibition of LDH-A stimulated mitochondrial function and drastically compromised the ability of the tumor cells to proliferate in low oxygen con...

New study shows antibiotic may protect the heart

...h. Researchers believe through the opening of the mitochondrial KATP channel of heart cells, rapamycin enables cells to maintain ATP levels. Mitochondria are cellular organelles critical for converting oxygen into ATP, the key fuel for cellular function. "Rapamycin may one day be beneficial as a potential therap...

Reversing 'hibernating' heart muscle focus of UB researchers

... undertake concurrent physiological, proteomic and mitochondrial functional studies in the swine model that will be...mans. Proteomic profiling will identify candidate mitochondrial proteins in the swine with established viable dysfunctional myocardium that do not have significant ...

ABCB6 is key to production of heme in hemoglobin

...said. The team found that the increase in ABCB6 in mitochondrial membranes caused the cells to make more porphyrin, the building block of heme. "Any disruption of this relationship can cause serious problems in the cell by altering levels of heme or porphyrins," Schuetz said. Armed with this new information, rese...

Rhesus monkeys in Nepal may provide new alternative for HIV/AIDS research

...acaques. The researchers did sequence analyses of mitochondrial DNA and examined the distribution of certain types of alleles, or pairs of genes, for genetic variations distributed across 17 chromosomes. They also looked for the presence of other alleles that are known to influence immunity and the rate of diseas...

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. ...

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...

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...

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...

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...

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...

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...

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 ...

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...

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...

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 ...

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...

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...

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...

'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...