Sample records for temperature-sensitive mutations un-7

  1. Neighborhood properties are important determinants of temperature sensitive mutations.

    Directory of Open Access Journals (Sweden)

    Svetlana Lockwood

    Full Text Available Temperature-sensitive (TS mutants are powerful tools to study gene function in vivo. These mutants exhibit wild-type activity at permissive temperatures and reduced activity at restrictive temperatures. Although random mutagenesis can be used to generate TS mutants, the procedure is laborious and unfeasible in multicellular organisms. Further, the underlying molecular mechanisms of the TS phenotype are poorly understood. To elucidate TS mechanisms, we used a machine learning method-logistic regression-to investigate a large number of sequence and structure features. We developed and tested 133 features, describing properties of either the mutation site or the mutation site neighborhood. We defined three types of neighborhood using sequence distance, Euclidean distance, and topological distance. We discovered that neighborhood features outperformed mutation site features in predicting TS mutations. The most predictive features suggest that TS mutations tend to occur at buried and rigid residues, and are located at conserved protein domains. The environment of a buried residue often determines the overall structural stability of a protein, thus may lead to reversible activity change upon temperature switch. We developed TS prediction models based on logistic regression and the Lasso regularized procedure. Through a ten-fold cross-validation, we obtained the area under the curve of 0.91 for the model using both sequence and structure features. Testing on independent datasets suggested that the model predicted TS mutations with a 50% precision. In summary, our study elucidated the molecular basis of TS mutants and suggested the importance of neighborhood properties in determining TS mutations. We further developed models to predict TS mutations derived from single amino acid substitutions. In this way, TS mutants can be efficiently obtained through experimentally introducing the predicted mutations.

  2. The Usher Syndrome Type IIIB Histidyl-tRNA Synthetase Mutation Confers Temperature Sensitivity. (United States)

    Abbott, Jamie A; Guth, Ethan; Kim, Cindy; Regan, Cathy; Siu, Victoria M; Rupar, C Anthony; Demeler, Borries; Francklyn, Christopher S; Robey-Bond, Susan M


    Histidyl-tRNA synthetase (HARS) is a highly conserved translation factor that plays an essential role in protein synthesis. HARS has been implicated in the human syndromes Charcot-Marie-Tooth (CMT) Type 2W and Type IIIB Usher (USH3B). The USH3B mutation, which encodes a Y454S substitution in HARS, is inherited in an autosomal recessive fashion and associated with childhood deafness, blindness, and episodic hallucinations during acute illness. The biochemical basis of the pathophysiologies linked to USH3B is currently unknown. Here, we present a detailed functional comparison of wild-type (WT) and Y454S HARS enzymes. Kinetic parameters for enzymes and canonical substrates were determined using both steady state and rapid kinetics. Enzyme stability was examined using differential scanning fluorimetry. Finally, enzyme functionality in a primary cell culture was assessed. Our results demonstrate that the Y454S substitution leaves HARS amino acid activation, aminoacylation, and tRNAHis binding functions largely intact compared with those of WT HARS, and the mutant enzyme dimerizes like the wild type does. Interestingly, during our investigation, it was revealed that the kinetics of amino acid activation differs from that of the previously characterized bacterial HisRS. Despite the similar kinetics, differential scanning fluorimetry revealed that Y454S is less thermally stable than WT HARS, and cells from Y454S patients grown at elevated temperatures demonstrate diminished levels of protein synthesis compared to those of WT cells. The thermal sensitivity associated with the Y454S mutation represents a biochemical basis for understanding USH3B.

  3. Temperature-sensitive mutations for live-attenuated Rift Valley fever vaccines: Implications from other RNA viruses

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    Shoko eNishiyama


    Full Text Available Rift Valley fever (RVF is a mosquito-borne zoonotic disease endemic to the African continent. RVF is characterized by high rate of abortions in ruminants and hemorrhagic fever, encephalitis or blindness in humans. RVF is caused by the Rift Valley fever virus (RVFV: genus Phlebovirus, family Bunyaviridae. Vaccination is the only known effective strategy to prevent the disease, but there are no licensed RVF vaccines available for humans. A live-attenuated vaccine candidate derived from the wild-type pathogenic Egyptian ZH548 strain, MP-12, has been conditionally licensed for veterinary use in the United States. MP-12 displays a temperature-sensitive (ts phenotype and does not replicate at 41oC. The ts mutation limits viral replication at a specific body temperature and may lead to an attenuation of the virus. Here we will review well-characterized ts mutations for RNA viruses, and further discuss the potential in designing novel live-attenuated vaccines for RVF.

  4. Screening mutations of OTOF gene in Chinese patients with auditory neuropathy, including a familial case of temperature-sensitive auditory neuropathy

    Directory of Open Access Journals (Sweden)

    Benedict-Alderfer Cindy


    Full Text Available Abstract Background Mutations in OTOF gene, encoding otoferlin, cause DFNB9 deafness and non-syndromic auditory neuropathy (AN. The aim of this study is to identify OTOF mutations in Chinese patients with non-syndromic auditory neuropathy. Methods 73 unrelated Chinese Han patients with AN, including one case of temperature sensitive non-syndromic auditory neuropathy (TS-NSRAN and 92 ethnicity-matched controls with normal hearing were screened. Forty-five pairs of PCR primers were designed to amplify all of the exons and their flanking regions of the OTOF gene. The PCR products were sequenced and analyzed for mutation identification. Results Five novel possibly pathogenic variants (c.1740delC, c.2975_2978delAG, c.1194T>A, c.1780G>A, c.4819C > T were identified in the group of 73 AN patients, in which two novel mutant alleles (c.2975_2978delAG + c.4819C > T were identified in one Chinese TS-NSRAN case. Besides, 10 non-pathogenic variants of the OTOF gene were found in AN patients and controls. Conclusions Screening revealed that mutations in the OTOF gene account for AN in 4 of 73(5.5% sporadic AN patients, which shows a lower genetic load of that gene in contrast to the previous studies based on other populations. Notably, we found two novel mutant alleles related to temperature sensitive non-syndromic auditory neuropathy. This mutation screening study further confirms that the OTOF gene contributes to ANs and to TS-NSRAN.

  5. Towards a male-only release system for SIT with the Queensland fruit fly, Bactrocera tryoni, using a genetic sexing strain with a temperature-sensitive lethal mutation. (United States)

    Meats, A; Maheswaran, P; Frommer, M; Sved, J


    Flies that are homozygous for the recessive autosomal mutation bent wings have a limited ability to fly and are less tolerant of high temperatures than normal flies in both the egg and puparial stages. The differences between the mutant and normal flies were found sufficient to be the basis of a genetic sexing strain. Genetic sexing strains were created using translocations of the autosome bearing the wild-type allele of bent wings (chromosome 2) to the Y chromosome, and crossing male flies carrying the translocation to mutant bent wings females. In the resulting strain, the females were homozygous for the bent wings mutation and the males were phenotypically normal for wing characters. Several translocations were recovered after irradiation, but only one translocation involving chromosome 2 was both stable and expressed in a stock that was vigorous enough for long-term viability. Unfortunately, all stocks containing the translocation showed high levels of temperature-dependent lethality, including, inexplicably, both males and females. Translocation stocks showing this effect included bent wings, another second chromosome mutation, white marks, and an otherwise normal stock. This phenomenon is probably rare, as it has not been reported before. It is likely that bent wings could be suitably used with another translocation.

  6. Escherichia coli mutants with a temperature-sensitive alcohol dehydrogenase.


    Lorowitz, W; CLARK, D.


    Mutants of Escherichia coli resistant to allyl alcohol were selected. Such mutants were found to lack alcohol dehydrogenase. In addition, mutants with temperature-sensitive alcohol dehydrogenase activity were obtained. These mutations, designated adhE, are all located at the previously described adh regulatory locus. Most adhE mutants were also defective in acetaldehyde dehydrogenase activity.

  7. Using Temperature Sensitive Paint Technology (United States)

    Hamner, M. P.; Popernack, T. G., Jr.; Owens, L. R.; Wahls, R. A.


    New facilities and test techniques afford research aerodynamicists many opportunities to investigate complex aerodynamic phenomena. For example, NASA Langley Research Center's National Transonic Facility (NTF) can hold Mach number, Reynolds number, dynamic pressure, stagnation temperature and stagnation pressure constant during testing. This is important because the wing twist associated with model construction may mask important Reynolds number effects associated with the flight vehicle. Beyond this, the NTF's ability to vary Reynolds number allows for important research into the study of boundary layer transition. The capabilities of facilities such as the NTF coupled with test techniques such as temperature sensitive paint yield data that can be applied not only to vehicle design but also to validation of computational methods. Development of Luminescent Paint Technology for acquiring pressure and temperature measurements began in the mid-1980s. While pressure sensitive luminescent paints (PSP) were being developed to acquire data for aerodynamic performance and loads, temperature sensitive luminescent paints (TSP) have been used for a much broader range of applications. For example, TSP has been used to acquire surface temperature data to determine the heating due to rotating parts in various types of mechanical systems. It has been used to determine the heating pattern(s) on circuit boards. And, it has been used in boundary layer analysis and applied to the validation of full-scale flight performance predictions. That is, data acquired on the same model can be used to develop trends from off design to full scale flight Reynolds number, e.g. to show the progression of boundary layer transition. A discussion of issues related to successfully setting-up TSP tests and using TSP systems for boundary layer studies is included in this paper, as well as results from a variety of TSP tests. TSP images included in this paper are all grey-scale so that similar to

  8. Overview of low temperature sensitization

    Energy Technology Data Exchange (ETDEWEB)

    Fox, M.J.; McCright, R.D.


    A review of the literature on low temperature sensitization (LTS) has been conducted to determine if LTS-related microstructural changes can occur in Type 304L stainless steel within the times and temperatures associated with nuclear waste storage. It was found that Type 304L stainless steel is susceptible to sensitization and LTS, and that cold work plays an important role in determining the rate of LTS. Severely cold worked Type 304L stainless steel would clearly develop LTS-related microstructural changes within the times and temperatures associated with nuclear waste storage. These changes could lead to increased susceptibility to corrosion. Significant improvements in the long-term resistance to sensitization, LTS and corrosion can be achieved by modest changes in alloy composition and fabrication practices. Therefore, Type 304L would not be the preferred alloy of construction for nuclear waste storage canisters. The final qualification of an alternate canister alloy should involve corrosion experiments on actual canisters. Suggestions for alternate canister alloys are 316L, 316LN, 316ELC, 347, and XM-19. 47 references, 4 figures.

  9. Theoretical study on ignition compensating temperature sensitivity

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    Mingfang Liu


    Full Text Available Temperature sensitivity of the propellant has significant influence on the interior ballistic performance of guns. Many physical and chemical approaches are employed to decrease this temperature sensitivity of the propellant. In this article, it is proposed that the temperature sensitivity of the propellant is changed by altering the factors required to ignition. A one-dimensional two-phase flow interior ballistic model is established to analyze the relation between ignition factors and temperature sensitivity. The simulation results show that the propellant temperature sensitivity is changed by altering the ignition factors. That is, the interior ballistic performance is affected by altering the size of fire hole, breaking liner pressure, and ignition location. Based on the simulation results, the temperature sensitivity can be controlled by matching of charges and intelligent control ignition system.

  10. The Y42H mutation in medium-chain acyl-CoA dehydrogenase, which is prevalent in babies identified by MS/MS-based newborn screening, is temperature sensitive

    DEFF Research Database (Denmark)

    O'Reilly, Linda; Bross, Peter; Corydon, Thomas J


    variant. To distinguish between effects of temperature on folding/assembly and the stability of the native enzyme, the thermal stability of the variant proteins was studied after expression and purification by dye affinity chromatography. This showed that, compared with the wild-type enzyme......Medium-chain acyl-CoA dehydrogenase (MCAD) is a homotetrameric flavoprotein which catalyses the initial step of the beta-oxidation of medium-chain fatty acids. Mutations in MCAD may cause disease in humans. A Y42H mutation is frequently found in babies identified by newborn screening with MS....../MS, yet there are no reports of patients presenting clinically with this mutation. As a basis for judging its potential consequences we have examined the protein phenotype of the Y42H mutation and the common disease-associated K304E mutation. Our studies of the intracellular biogenesis of the variant...

  11. The defective phosphoribosyl diphosphate synthase in a temperature-sensitive prs-2 mutant of Escherichia coli is compensated by increased enzyme synthesis

    DEFF Research Database (Denmark)

    Post, David A.; Switzer, Robert L.; Hove-Jensen, Bjarne


    An Escherichia coli strain which is temperature-sensitive for growth due to a mutation (prs-2) causing a defective phosphoribosyl diphosphate (PRPP) synthase has been characterized. The temperature-sensitive mutation was mapped to a 276 bp HindIII-BssHII DNA fragment located within the open readi...

  12. Hypomorphic Temperature-Sensitive Alleles of NSDHL Cause CK Syndrome (United States)

    McLarren, Keith W.; Severson, Tesa M.; du Souich, Christèle; Stockton, David W.; Kratz, Lisa E.; Cunningham, David; Hendson, Glenda; Morin, Ryan D.; Wu, Diane; Paul, Jessica E.; An, Jianghong; Nelson, Tanya N.; Chou, Athena; DeBarber, Andrea E.; Merkens, Louise S.; Michaud, Jacques L.; Waters, Paula J.; Yin, Jingyi; McGillivray, Barbara; Demos, Michelle; Rouleau, Guy A.; Grzeschik, Karl-Heinz; Smith, Raffaella; Tarpey, Patrick S.; Shears, Debbie; Schwartz, Charles E.; Gecz, Jozef; Stratton, Michael R.; Arbour, Laura; Hurlburt, Jane; Van Allen, Margot I.; Herman, Gail E.; Zhao, Yongjun; Moore, Richard; Kelley, Richard I.; Jones, Steven J.M.; Steiner, Robert D.; Raymond, F. Lucy; Marra, Marco A.; Boerkoel, Cornelius F.


    CK syndrome (CKS) is an X-linked recessive intellectual disability syndrome characterized by dysmorphism, cortical brain malformations, and an asthenic build. Through an X chromosome single-nucleotide variant scan in the first reported family, we identified linkage to a 5 Mb region on Xq28. Sequencing of this region detected a segregating 3 bp deletion (c.696_698del [p.Lys232del]) in exon 7 of NAD(P) dependent steroid dehydrogenase-like (NSDHL), a gene that encodes an enzyme in the cholesterol biosynthesis pathway. We also found that males with intellectual disability in another reported family with an NSDHL mutation (c.1098 dup [p.Arg367SerfsX33]) have CKS. These two mutations, which alter protein folding, show temperature-sensitive protein stability and complementation in Erg26-deficient yeast. As described for the allelic disorder CHILD syndrome, cells and cerebrospinal fluid from CKS patients have increased methyl sterol levels. We hypothesize that methyl sterol accumulation, not only cholesterol deficiency, causes CKS, given that cerebrospinal fluid cholesterol, plasma cholesterol, and plasma 24S-hydroxycholesterol levels are normal in males with CKS. In summary, CKS expands the spectrum of cholesterol-related disorders and insight into the role of cholesterol in human development. PMID:21129721

  13. The experienced temperature sensitivity and regulation survey (United States)

    Van Someren, Eus J. W.; Dekker, Kim; Te Lindert, Bart H. W.; Benjamins, Jeroen S.; Moens, Sarah; Migliorati, Filippo; Aarts, Emmeke; van der Sluis, Sophie


    ABSTRACT Individuals differ in thermosensitivity, thermoregulation, and zones of thermoneutrality and thermal comfort. Whereas temperature sensing and -effectuating processes occur in part unconsciously and autonomic, awareness of temperature and thermal preferences can affect thermoregulatory behavior as well. Quantification of trait-like individual differences of thermal preferences and experienced temperature sensitivity and regulation is therefore relevant to obtain a complete understanding of human thermophysiology. Whereas several scales have been developed to assess instantaneous appreciation of heat and cold exposure, a comprehensive scale dedicated to assess subjectively experienced autonomic or behavioral thermoregulatory activity has been lacking so far. We constructed a survey that specifically approaches these domains from a trait-like perspective, sampled 240 volunteers across a wide age range, and analyzed the emergent component structure. Participants were asked to report their thermal experiences, captured in 102 questions, on a 7-point bi-directional Likert scale. In a second set of 32 questions, participants were asked to indicate the relative strength of experiences across different body locations. Principal component analyses extracted 21 meaningful dimensions, which were sensitive to sex-differences and age-related changes. The questions were also assessed in a matched sample of 240 people with probable insomnia to evaluate the sensitivity of these dimensions to detect group differences in a case-control design. The dimensions showed marked mean differences between cases and controls. The survey thus has discriminatory value. It can freely be used by anyone interested in studying individual or group differences in thermosensitivity and thermoregulation. PMID:27227080

  14. Allele-specific suppression of the temperature sensitivity of fitA/fitB ...

    Indian Academy of Sciences (India)

    The temperature sensitive transcription defective mutant of Escherichia coli originally called fitA76 has been shown to harbour two missense mutations namely pheS5 and fit95. In order to obtain a suppressor of fitA76, possibly mapping in rpoD locus, a Ts+ derivative (JV4) was isolated from a fitA76 mutant. It was found that ...

  15. Divergent apparent temperature sensitivity of terrestrial ecosystem respiration (United States)

    Bing Song; Shuli Niu; Ruise Luo; Yiqi Luo; Jiquan Chen; Guirui Yu; Janusz Olejnik; Georg Wohlfahrt; Gerard Kiely; Ako Noormets; Leonardo Montagnani; Alessandro Cescatti; Vincenzo Magliulo; Beverly Elizabeth Law; Magnus Lund; Andrej Varlagin; Antonio Raschi; Matthias Peichl; Mats B. Nilsson; Lutz Merbold


    Recent studies revealed convergent temperature sensitivity of ecosystem respiration (Re) within aquatic ecosystems and between terrestrial and aquatic ecosystems. We do not know yet whether various terrestrial ecosystems have consistent or divergent temperature sensitivity. Here, we synthesized 163 eddy covariance flux sites across the world and...

  16. Ultrahigh temperature-sensitive silicon MZI with titania cladding

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    Jong-Moo eLee


    Full Text Available We present a possibility of intensifying temperature sensitivity of a silicon Mach-Zehnder interferometer (MZI by using a highly negative thermo-optic property of titania (TiO2. Temperature sensitivity of an asymmetric silicon MZI with a titania cladding is experimentally measured from +18pm/C to -340 pm/C depending on design parameters of MZI.

  17. Temperature sensitivity of decomposition of soil organic carbon fractions (United States)

    Hilasvuori, Emmi; Järvenpää, Marko; Akujärvi, Anu; Arppe, Laura; Christensen, Bent T.; Fritze, Hannu; Kaasalainen, Mikko; Karhu, Kristiina; Oinonen, Markku; Palonen, Vesa; Pitkänen, Juha-Matti; Repo, Anna; Vanhala, Pekka; Liski, Jari


    Knowing the temperature sensitivity of soil organic matter (SOM) decomposition is important for estimating the release of carbon from soil to the atmosphere in response to global warming. This temperature sensitivity is known relatively well for the most labile SOM fractions but still quite poorly for more recalcitrant fractions that represent the great majority of SOM. We report results for the temperature sensitivity of various SOM fractions in two different experiments in which we utilized natural abundances of carbon isotopes 13C and 14C combined with Bayesian mathematical modelling. In one experiment, the different age fractions were distinguished based on depth in a peat profile. In the other experiment, the age fractions were separated based on a time series of conversion from C3 vegetation to C4 vegetation. In both experiments, the temperature sensitivity of the SOM fractions was estimated by measuring the carbon isotope composition of heterotrophic soil respiration at different temperatures in laboratory. The results from these experiments suggest that the temperature sensitivity of unprotected SOM fractions increases with age, but if an environmental factor, such as bonding to soil minerals, limits decomposition of a SOM fraction, the temperature sensitivity is reduced. Our results are in agreement with the theory that suggests that in soil without environmental, physical or chemical protection, temperature sensitivity of carbon compounds is mainly determined by its chemical structure. The more complex the structure is the higher activation energy is needed and the higher its temperature sensitivity. Since SOM enriches with more complicated carbon compounds with time, this leads to increase in temperature sensitivity as SOM ages. However, our results also indicate that if the soil carbon is associated with minerals it might exhibit lower temperature sensitivities than when the carbon is "free" in the soil. Since the mineral associated carbon can have high

  18. Analysis of vaccinia virus temperature-sensitive I7L mutants reveals two potential functional domains

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    Byrd Chelsea M


    Full Text Available Abstract As an approach to initiating a structure-function analysis of the vaccinia virus I7L core protein proteinase, a collection of conditional-lethal mutants in which the mutation had been mapped to the I7L locus were subjected to genomic sequencing and phenotypic analyses. Mutations in six vaccinia virus I7L temperature sensitive mutants fall into two groups: changes at three positions at the N-terminal end between amino acids 29 and 37 and two different substitutions at amino acid 344, near the catalytic domain. Regardless of the position of the mutation, mutants at the non-permissive temperature failed to cleave core protein precursors and had their development arrested prior to core condensation. Thus it appears that the two clusters of mutations may affect two different functional domains required for proteinase activity.

  19. Magnetocaloric effect in temperature-sensitive magnetic fluids

    Indian Academy of Sciences (India)

    The magnetocaloric properties of three different temperature-sensitive magnetic fluids were studied. The pyromagnetic coefficient for all the materials were obtained and it was found that this property depends on physical and magnetic properties like size, magnetization and Curie temperature. A theoretical model was ...

  20. Dopamine modulates metabolic rate and temperature sensitivity in Drosophila melanogaster.

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    Taro Ueno

    Full Text Available Homeothermal animals, such as mammals, maintain their body temperature by heat generation and heat dissipation, while poikilothermal animals, such as insects, accomplish it by relocating to an environment of their favored temperature. Catecholamines are known to regulate thermogenesis and metabolic rate in mammals, but their roles in other animals are poorly understood. The fruit fly, Drosophila melanogaster, has been used as a model system for the genetic studies of temperature preference behavior. Here, we demonstrate that metabolic rate and temperature sensitivity of some temperature sensitive behaviors are regulated by dopamine in Drosophila. Temperature-sensitive molecules like dTrpA1 and shi(ts induce temperature-dependent behavioral changes, and the temperature at which the changes are induced were lowered in the dopamine transporter-defective mutant, fumin. The mutant also displays a preference for lower temperatures. This thermophobic phenotype was rescued by the genetic recovery of the dopamine transporter in dopamine neurons. Flies fed with a dopamine biosynthesis inhibitor (3-iodo-L-tyrosine, which diminishes dopamine signaling, exhibited preference for a higher temperature. Furthermore, we found that the metabolic rate is up-regulated in the fumin mutant. Taken together, dopamine has functions in the temperature sensitivity of behavioral changes and metabolic rate regulation in Drosophila, as well as its previously reported functions in arousal/sleep regulation.

  1. Single site suppressors of a fission yeast temperature-sensitive mutant in cdc48 identified by whole genome sequencing. (United States)

    Marinova, Irina N; Engelbrecht, Jacob; Ewald, Adrian; Langholm, Lasse L; Holmberg, Christian; Kragelund, Birthe B; Gordon, Colin; Nielsen, Olaf; Hartmann-Petersen, Rasmus


    The protein called p97 in mammals and Cdc48 in budding and fission yeast is a homo-hexameric, ring-shaped, ubiquitin-dependent ATPase complex involved in a range of cellular functions, including protein degradation, vesicle fusion, DNA repair, and cell division. The cdc48+ gene is essential for viability in fission yeast, and point mutations in the human orthologue have been linked to disease. To analyze the function of p97/Cdc48 further, we performed a screen for cold-sensitive suppressors of the temperature-sensitive cdc48-353 fission yeast strain. In total, 29 independent pseudo revertants that had lost the temperature-sensitive growth defect of the cdc48-353 strain were isolated. Of these, 28 had instead acquired a cold-sensitive phenotype. Since the suppressors were all spontaneous mutants, and not the result of mutagenesis induced by chemicals or UV irradiation, we reasoned that the genome sequences of the 29 independent cdc48-353 suppressors were most likely identical with the exception of the acquired suppressor mutations. This prompted us to test if a whole genome sequencing approach would allow us to map the mutations. Indeed genome sequencing unambiguously revealed that the cold-sensitive suppressors were all second site intragenic cdc48 mutants. Projecting these onto the Cdc48 structure revealed that while the original temperature-sensitive G338D mutation is positioned near the central pore in the hexameric ring, the suppressor mutations locate to subunit-subunit and inter-domain boundaries. This suggests that Cdc48-353 is structurally compromized at the restrictive temperature, but re-established in the suppressor mutants. The last suppressor was an extragenic frame shift mutation in the ufd1 gene, which encodes a known Cdc48 co-factor. In conclusion, we show, using a novel whole genome sequencing approach, that Cdc48-353 is structurally compromized at the restrictive temperature, but stabilized in the suppressors.

  2. Quantifying the bending of bilayer temperature-sensitive hydrogels (United States)

    Dong, Chenling; Chen, Bin


    Stimuli-responsive hydrogels can serve as manipulators, including grippers, sensors, etc., where structures can undergo significant bending. Here, a finite-deformation theory is developed to quantify the evolution of the curvature of bilayer temperature-sensitive hydrogels when subjected to a temperature change. Analysis of the theory indicates that there is an optimal thickness ratio to acquire the largest curvature in the bilayer and also suggests that the sign or the magnitude of the curvature can be significantly affected by pre-stretches or small pores in the bilayer. This study may provide important guidelines in fabricating temperature-responsive bilayers with desirable mechanical performance.

  3. Water Recycling removal using temperature-sensitive hydronen

    Energy Technology Data Exchange (ETDEWEB)

    Rana B. Gupta


    The overall objective of this project was to study the proposed Water Recycling/Removal Using Temperature-Sensitive Hydrogels. The main element of this technology is the design of a suitable hydrogel that can perform needed water separation for pulp and paper industry. The specific topics studied are to answer following questions: (a) Can water be removed using hydrogel from large molecules such as lignin? (b) Can the rate of separation be made faster? (c) What are the molecular interactions with hydrogel surface? (d) Can a hydrogel be designed for a high ionic strength and high temperature? Summary of the specific results are given.

  4. The relationship between virtual body ownership and temperature sensitivity. (United States)

    Llobera, Joan; Sanchez-Vives, M V; Slater, Mel


    In the rubber hand illusion, tactile stimulation seen on a rubber hand, that is synchronous with tactile stimulation felt on the hidden real hand, can lead to an illusion of ownership over the rubber hand. This illusion has been shown to produce a temperature decrease in the hidden hand, suggesting that such illusory ownership produces disownership of the real hand. Here, we apply immersive virtual reality (VR) to experimentally investigate this with respect to sensitivity to temperature change. Forty participants experienced immersion in a VR with a virtual body (VB) seen from a first-person perspective. For half the participants, the VB was consistent in posture and movement with their own body, and in the other half, there was inconsistency. Temperature sensitivity on the palm of the hand was measured before and during the virtual experience. The results show that temperature sensitivity decreased in the consistent compared with the inconsistent condition. Moreover, the change in sensitivity was significantly correlated with the subjective illusion of virtual arm ownership but modulated by the illusion of ownership over the full VB. This suggests that a full body ownership illusion results in a unification of the virtual and real bodies into one overall entity-with proprioception and tactile sensations on the real body integrated with the visual presence of the VB. The results are interpreted in the framework of a 'body matrix' recently introduced into the literature.

  5. Substrate-dependent temperature sensitivity of soil organic matter decomposition (United States)

    Myachina, Olga; Blagodatskaya, Evgenia


    Activity of extracellular enzymes responsible for decomposition of organics is substrate dependent. Quantity of the substrate is the main limiting factor for enzymatic or microbial heterotrophic activity in soils. Different mechanisms of enzymes response to temperature suggested for low and high substrate availability were never proved for real soil conditions. We compared the temperature responses of enzymes-catalyzed reactions in soils. Basing on Michaelis-Menten kinetics we determined the enzymes affinity to substrate (Km) and mineralization potential of heterotrophic microorganisms (Vmax) 1) for three hydrolytic enzymes: β-1,4-glucosidase, N-acetyl- β -D-glucosaminidase and phosphatase by the application of fluorogenically labeled substrates and 2) for mineralization of 14C-labeled glucose by substrate-dependent respiratory response. Here we show that the amount of available substrate is responsible for temperature sensitivity of hydrolysis of polymers in soil, whereas monomers oxidation to CO2 does not depend on substrate amount and is mainly temperature governed. We also found that substrate affinity of enzymes (which is usually decreases with the temperature) differently responded to warming for the process of depolymerisation versus monomers oxidation. We suggest the mechanism to temperature acclimation based on different temperature sensitivity of enzymes kinetics for hydrolysis of polymers and for monomers oxidation.

  6. File list: His.Adl.20.AllAg.Temperature_sensitive_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Adl.20.AllAg.Temperature_sensitive_cells dm3 Histone Adult Temperature ...

  7. File list: His.Adl.05.AllAg.Temperature_sensitive_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Adl.05.AllAg.Temperature_sensitive_cells dm3 Histone Adult Temperature ...

  8. File list: His.Adl.50.AllAg.Temperature_sensitive_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Adl.50.AllAg.Temperature_sensitive_cells dm3 Histone Adult Temperature ...

  9. File list: His.Adl.10.AllAg.Temperature_sensitive_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Adl.10.AllAg.Temperature_sensitive_cells dm3 Histone Adult Temperature ...

  10. Greater temperature sensitivity of plant phenology at colder sites

    DEFF Research Database (Denmark)

    Prevey, Janet; Vellend, Mark; Ruger, Nadja


    Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance...... at colder sites. To test this hypothesis, we examined up to 20 years of phenology data for 47 tundra plant species at 18 high-latitude sites along a climatic gradient. Across all species, the timing of leaf emergence and flowering was more sensitive to a given increase in summer temperature at colder than...... warmer high-latitude locations. A similar pattern was seen over time for the flowering phenology of a widespread species, Cassiope tetragona. These are among the first results highlighting differential phenological responses of plants across a climatic gradient and suggest the possibility of convergence...

  11. Engineering a temperature sensitive tobacco etch virus protease. (United States)

    Wong, J; Chen, X; Truong, K


    Since tobacco etch virus protease (TEVp) has a high specificity and efficiency in cleaving its target substrates, many groups have attempted to engineer conditional control of its activity. Temperature induction is widely used for modulating gene function because it has fast temporal response, good penetrability and applicability to many model organisms. Here, we engineered a temperature sensitive TEVp (tsTEVp) by using N-terminal truncations to TEVp that achieved efficient proteolysis on a timescale of 4 h after 30°C induction, while remaining relatively inactive at 37°C. As demonstration, tsTEVp was used to generate temperature-induced biological responses for protein translocation, protein degradation and Ca2+-mediated cellular blebbing. Lastly, tsTEVp and their engineered target substrates could find applications in engineered synthetic biological systems. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail:

  12. Glucose- and temperature-sensitive nanoparticles for insulin delivery. (United States)

    Wu, Jun-Zi; Williams, Gareth R; Li, He-Yu; Wang, Dongxiu; Wu, Huanling; Li, Shu-De; Zhu, Li-Min


    Glucose- and temperature-sensitive polymers of a phenylboronic acid derivative and diethylene glycol dimethacrylate (poly(3-acrylamidophenyl boronic acid-b-diethylene glycol methyl ether methacrylate); p(AAPBA-b-DEGMA)) were prepared by reversible addition-fragmentation chain transfer polymerization. Successful polymerization was evidenced by 1H nuclear magnetic resonance and infrared spectroscopy, and the polymers were further explored in terms of their glass transition temperatures and by gel permeation chromatography (GPC). The materials were found to be temperature sensitive, with lower critical solution temperatures in the region of 12°C-47°C depending on the monomer ratio used for reaction. The polymers could be self-assembled into nanoparticles (NPs), and the zeta potential and size of these particles were determined as a function of temperature and glucose concentration. Subsequently, the optimum NP formulation was loaded with insulin, and the drug release was studied. We found that insulin was easily encapsulated into the p(AAPBA-b-DEGMA) NPs, with a loading capacity of ~15% and encapsulation efficiency of ~70%. Insulin release could be regulated by changes in temperature and glucose concentration. Furthermore, the NPs were non-toxic both in vitro and in vivo. Finally, the efficacy of the formulations at managing blood glucose levels in a murine hyperglycemic diabetes model was studied. The insulin-loaded NPs could reduce blood glucose levels over an extended period of 48 h. Since they are both temperature and glucose sensitive and offer a sustained-release profile, these systems may comprise potent new formulations for insulin delivery.

  13. Temperature sensitivity of organic compound destruction in SCWO process. (United States)

    Tan, Yaqin; Shen, Zhemin; Guo, Weimin; Ouyang, Chuang; Jia, Jinping; Jiang, Weili; Zhou, Haiyun


    To study the temperature sensitivity of the destruction of organic compounds in supercritical water oxidation process (SCWO), oxidation effects of twelve chemicals in supercritical water were investigated. The SCWO reaction rates of different compounds improved to varying degrees with the increase of temperature, so the highest slope of the temperature-effect curve (imax) was defined as the maximum ratio of removal ratio to working temperature. It is an important index to stand for the temperature sensitivity effect in SCWO. It was proven that the higher imax is, the more significant the effect of temperature on the SCWO effect is. Since the high-temperature area of SCWO equipment is subject to considerable damage from fatigue, the temperature is of great significance in SCWO equipment operation. Generally, most compounds (imax > 0.25) can be completely oxidized when the reactor temperature reaches 500°C. However, some compounds (imax > 0.25) need a higher temperature for complete oxidation, up to 560°C. To analyze the correlation coefficients between imax and various molecular descriptors, a quantum chemical method was used in this study. The structures of the twelve organic compounds were optimized by the Density Functional Theory B3LYP/6-311G method, as well as their quantum properties. It was shown that six molecular descriptors were negatively correlated to imax while other three descriptors were positively correlated to imax. Among them, dipole moment had the greatest effect on the oxidation thermodynamics of the twelve organic compounds. Once a correlation between molecular descriptors and imax is established, SCWO can be run at an appropriate temperature according to molecular structure. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  14. File list: DNS.Adl.05.AllAg.Temperature_sensitive_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  16. File list: DNS.Adl.20.AllAg.Temperature_sensitive_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  17. Temperature sensitivity of methanogenesis in a thermokarst lake sediment core (United States)

    Heslop, J. K.; Walter Anthony, K. M.; Grosse, G.; Anthony, P.; Bondurant, A.


    Little is known about temperature sensitivity of permafrost organic carbon (OC) mineralization over time scales of years to centuries following thaw. Due to their formation and thaw histories, taliks (thaw bulbs) beneath thermokarst lakes provide a unique natural laboratory from which to examine how permafrost thawed in saturated anaerobic conditions responds to changes in temperature following long periods of time since thaw. We anaerobically incubated samples from a 590 cm thermokarst lake sediment core near Fairbanks, Alaska at four temperatures (0, 3, 10, and 25 ºC) bracketing observed talik temperatures. We show that since initial thaw 400 yr BP CH4 production shifts from being most sensitive to at lower (0-3 ºC; Q10-EC=1.15E7) temperatures to being most sensitive at higher (10-25 ºC; Q10-EC=67) temperatures. Frozen sediments collected from beneath the talik, thawed at the commencement of the incubation, had significant (p ≤ 0.05) increases in CH4 production rates at lower temperatures but did not show significant CH4 production rate increases at higher temperatures (10-25 ºC). We hypothesize the thawing of sediments removed a major barrier to C mineralization, leading to rapid initial permafrost C mineralization and preferential mineralization of the most biolabile OC compounds. In contrast, sediments which had been thawed beneath the lake for longer periods of time did not experience statistically significant increases in CH4 production at lower temperatures (0-10 ºC), but had high temperature sensitivities at higher temperatures (10-25 ºC). We believe these rate increases are due to warmer temperatures in the experimental incubations crossing activation energy thresholds, allowing previously recalcitrant fractions of OC to be utilized, and/or the presence of different microbial communities adapted to thawed sediments. Recently-deposited sediments at shallow depths in the lake core experienced increases in CH4 production across all incubation

  18. Mass Rearing of Temperature Sensitive Genetic Sexing Strains in the Mediterranean Fruit Fly (Ceratitis Capitata)

    Energy Technology Data Exchange (ETDEWEB)

    Caceres, C. [FAO/IAEA Agriculture and Biotechnology Laboratory, Entomology Unit, A-2444 Seibersdorf (Austria)]. E-mail:


    Genetic sexing strains (GSS) based on the temperature sensitive lethal(tsl) mutation are being used to produce sterile male medflies for large scale sterile insect technique (SIT) programmes for this pest. The use of male-only strains increases the overall efficiency of the technique. Currently more than 1.4 billion sterile male-only pupae are produced per week in different facilities around the world. Due to the mutations used to construct these strains, that is, translocations and selectable markers, they require different and more careful mass rearing procedures than do bisexual strains (BSS). The basic rearing technology has been developed and can be used to produce only males on a predictable basis to a level of 99.9% accuracy. If specific rearing procedures are followed, then tsl-based GSS has a rearing efficiency that is equal to that of a BSS and it is already know that males produced by the tsl-based GSS are of equal quality to males produced by BSS. Based on current rearing technology the cost of production of male pupae is about the same for both types of strain. This is due to the large colony that is required for the tsl-based GSS. This paper discusses the considerations that need to be taken into account during mass rearing of GSS and identifies the most efficient production processes that are currently available. (author)

  19. Mechanisms of temperature sensitivity of attenuated Urabe mumps virus. (United States)

    Schinkel, Stephanie C Burke; Rubin, Steven; Wright, Kathryn E


    Temperature sensitivity is a phenotype often associated with attenuation of viruses. Previously, we purified several mumps variants from an incompletely attenuated Urabe strain live attenuated vaccine. Here we characterize one isolate that is sensitive to growth at high temperature. This virus was attenuated in a small animal model of mumps virulence, and we identified unique coding substitutions in the hemagglutinin-neuraminidase (HN), the viral polymerase (L) gene, and a non-coding substitution close to the anti-genome promoter sequences. At the non-permissive temperature, transcription of viral mRNAs and production of the replication intermediate were reduced compared to events at the permissive temperature and to a non-ts virulent Urabe virus. As well, synthesis of viral proteins was also reduced at the higher temperature. While the actual sequence substitutions in the ts virus were unique, the pattern of substitutions in HN, L and genome end sequences is similar to another attenuated Urabe virus previously described by us. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Single site suppressors of a fission yeast temperature-sensitive mutant in cdc48 identified by whole genome sequencing.

    Directory of Open Access Journals (Sweden)

    Irina N Marinova

    Full Text Available The protein called p97 in mammals and Cdc48 in budding and fission yeast is a homo-hexameric, ring-shaped, ubiquitin-dependent ATPase complex involved in a range of cellular functions, including protein degradation, vesicle fusion, DNA repair, and cell division. The cdc48+ gene is essential for viability in fission yeast, and point mutations in the human orthologue have been linked to disease. To analyze the function of p97/Cdc48 further, we performed a screen for cold-sensitive suppressors of the temperature-sensitive cdc48-353 fission yeast strain. In total, 29 independent pseudo revertants that had lost the temperature-sensitive growth defect of the cdc48-353 strain were isolated. Of these, 28 had instead acquired a cold-sensitive phenotype. Since the suppressors were all spontaneous mutants, and not the result of mutagenesis induced by chemicals or UV irradiation, we reasoned that the genome sequences of the 29 independent cdc48-353 suppressors were most likely identical with the exception of the acquired suppressor mutations. This prompted us to test if a whole genome sequencing approach would allow us to map the mutations. Indeed genome sequencing unambiguously revealed that the cold-sensitive suppressors were all second site intragenic cdc48 mutants. Projecting these onto the Cdc48 structure revealed that while the original temperature-sensitive G338D mutation is positioned near the central pore in the hexameric ring, the suppressor mutations locate to subunit-subunit and inter-domain boundaries. This suggests that Cdc48-353 is structurally compromized at the restrictive temperature, but re-established in the suppressor mutants. The last suppressor was an extragenic frame shift mutation in the ufd1 gene, which encodes a known Cdc48 co-factor. In conclusion, we show, using a novel whole genome sequencing approach, that Cdc48-353 is structurally compromized at the restrictive temperature, but stabilized in the suppressors.

  1. Temperature Sensitivity as a Microbial Trait Using Parameters from Macromolecular Rate Theory. (United States)

    Alster, Charlotte J; Baas, Peter; Wallenstein, Matthew D; Johnson, Nels G; von Fischer, Joseph C


    The activity of soil microbial extracellular enzymes is strongly controlled by temperature, yet the degree to which temperature sensitivity varies by microbe and enzyme type is unclear. Such information would allow soil microbial enzymes to be incorporated in a traits-based framework to improve prediction of ecosystem response to global change. If temperature sensitivity varies for specific soil enzymes, then determining the underlying causes of variation in temperature sensitivity of these enzymes will provide fundamental insights for predicting nutrient dynamics belowground. In this study, we characterized how both microbial taxonomic variation as well as substrate type affects temperature sensitivity. We measured β-glucosidase, leucine aminopeptidase, and phosphatase activities at six temperatures: 4, 11, 25, 35, 45, and 60°C, for seven different soil microbial isolates. To calculate temperature sensitivity, we employed two models, Arrhenius, which predicts an exponential increase in reaction rate with temperature, and Macromolecular Rate Theory (MMRT), which predicts rate to peak and then decline as temperature increases. We found MMRT provided a more accurate fit and allowed for more nuanced interpretation of temperature sensitivity in all of the enzyme × isolate combinations tested. Our results revealed that both the enzyme type and soil isolate type explain variation in parameters associated with temperature sensitivity. Because we found temperature sensitivity to be an inherent and variable property of an enzyme, we argue that it can be incorporated as a microbial functional trait, but only when using the MMRT definition of temperature sensitivity. We show that the Arrhenius metrics of temperature sensitivity are overly sensitive to test conditions, with activation energy changing depending on the temperature range it was calculated within. Thus, we propose the use of the MMRT definition of temperature sensitivity for accurate interpretation of

  2. Temperature Sensitivity as a Microbial Trait Using Parameters from Macromolecular Rate Theory

    Directory of Open Access Journals (Sweden)

    Charlotte Jean Alster


    Full Text Available The activity of soil microbial extracellular enzymes is strongly controlled by temperature, yet the degree to which temperature sensitivity varies by microbe and enzyme type is unclear. Such information would allow soil microbial enzymes to be incorporated in a traits-based framework to improve prediction of ecosystem response to global change. If temperature sensitivity varies for specific soil enzymes, then determining the underlying causes of variation in temperature sensitivity of these enzymes will provide fundamental insights for predicting nutrient dynamics belowground. In this study, we characterized how both microbial taxonomic variation as well as substrate type affects temperature sensitivity. We measured β-glucosidase, leucine aminopeptidase, and phosphatase activities at six temperatures: 4, 11, 25, 35, 45, and 60°C, for seven different soil microbial isolates. To calculate temperature sensitivity, we employed two models, Arrhenius, which predicts an exponential increase in reaction rate with temperature, and Macromolecular Rate Theory (MMRT, which predicts rate to peak and then decline as temperature increases. We found MMRT provided a more accurate fit and allowed for more nuanced interpretation of temperature sensitivity in all of the enzyme × isolate combinations tested. Our results revealed that both the enzyme type and soil isolate type explain variation in parameters associated with temperature sensitivity. Because we found temperature sensitivity to be an inherent and variable property of an enzyme, we argue that it can be incorporated as a microbial functional trait, but only when using the MMRT definition of temperature sensitivity. We show that the Arrhenius metrics of temperature sensitivity are overly sensitive to test conditions, with activation energy changing depending on the temperature range it was calculated within. Thus, we propose the use of the MMRT definition of temperature sensitivity for accurate

  3. Temperature-Sensitive Coating Sensor Based on Hematite (United States)

    Bencic, Timothy J.


    A temperature-sensitive coating, based on hematite (iron III oxide), has been developed to measure surface temperature using spectral techniques. The hematite powder is added to a binder that allows the mixture to be painted on the surface of a test specimen. The coating dynamically changes its relative spectral makeup or color with changes in temperature. The color changes from a reddish-brown appearance at room temperature (25 C) to a black-gray appearance at temperatures around 600 C. The color change is reversible and repeatable with temperature cycling from low to high and back to low temperatures. Detection of the spectral changes can be recorded by different sensors, including spectrometers, photodiodes, and cameras. Using a-priori information obtained through calibration experiments in known thermal environments, the color change can then be calibrated to yield accurate quantitative temperature information. Temperature information can be obtained at a point, or over an entire surface, depending on the type of equipment used for data acquisition. Because this innovation uses spectrophotometry principles of operation, rather than the current methods, which use photoluminescence principles, white light can be used for illumination rather than high-intensity short wavelength excitation. The generation of high-intensity white (or potentially filtered long wavelength light) is much easier, and is used more prevalently for photography and video technologies. In outdoor tests, the Sun can be used for short durations as an illumination source as long as the amplitude remains relatively constant. The reflected light is also much higher in intensity than the emitted light from the inefficient current methods. Having a much brighter surface allows a wider array of detection schemes and devices. Because color change is the principle of operation, the development of high-quality, lower-cost digital cameras can be used for detection, as opposed to the high-cost imagers

  4. File list: Unc.Adl.20.AllAg.Temperature_sensitive_cells [Chip-atlas[Archive

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    Lifescience Database Archive (English)

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  12. File list: ALL.Adl.20.AllAg.Temperature_sensitive_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  18. File list: Oth.Adl.20.AllAg.Temperature_sensitive_cells [Chip-atlas[Archive

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  20. The defective phosphoribosyl diphosphate synthase in a temperature-sensitive prs-2 mutant of Escherichia coli is compensated by increased enzyme synthesis. (United States)

    Post, D A; Switzer, R L; Hove-Jensen, B


    An Escherichia coli strain which is temperature-sensitive for growth due to a mutation (prs-2) causing a defective phosphoribosyl diphosphate (PRPP) synthase has been characterized. The temperature-sensitive mutation was mapped to a 276 bp HindIII-BssHII DNA fragment located within the open reading frame specifying the PRPP synthase polypeptide. Cloning and sequencing of the mutant allele revealed two mutations. One, a G --> A transition, located in the ninth codon, was responsible for the temperature-conditional phenotype and resulted in a serine residue at this position. The wild-type codon at this position specified a glycine residue that is conserved among PRPP synthases across a broad phylogenetic range. Cells harbouring the glycine-to-serine alteration specified by a plasmid contained approximately 50% of the PRPP synthase activity of cells harbouring a plasmid-borne wild-type allele, both grown at 25 degrees C. The mutant enzyme had nearly normal heat stability, as long as it was synthesized at 25 degrees C. In contrast, there was hardly any PRPP synthase activity or anti-PRPP synthase antibody cross-reactive material present in cells harbouring the glycine to serine alteration following temperature shift to 42 degrees C. The other mutation was a C --> T transition located 39 bp upstream of the G --> A mutation, i.e. outside the coding sequence and close to the Shine-Dalgarno sequence. Cells harbouring only the C --> T mutation in a plasmid contained approximately three times as much PRPP synthase activity as a strain harbouring a plasmid-borne wild-type prs allele. In cells harbouring both mutations, the C --> T mutation appeared to compensate for the G --> A mutation by increasing the amount of a partially defective enzyme at the permissive temperature.

  1. West Nile Virus Temperature Sensitivity and Avian Virulence Are Modulated by NS1-2B Polymorphisms. (United States)

    Dietrich, Elizabeth A; Langevin, Stanley A; Huang, Claire Y-H; Maharaj, Payal D; Delorey, Mark J; Bowen, Richard A; Kinney, Richard M; Brault, Aaron C


    West Nile virus (WNV) replicates in a wide variety of avian species, which serve as reservoir and amplification hosts. WNV strains isolated in North America, such as the prototype strain NY99, elicit a highly pathogenic response in certain avian species, notably American crows (AMCRs; Corvus brachyrhynchos). In contrast, a closely related strain, KN3829, isolated in Kenya, exhibits a low viremic response with limited mortality in AMCRs. Previous work has associated the difference in pathogenicity primarily with a single amino acid mutation at position 249 in the helicase domain of the NS3 protein. The NY99 strain encodes a proline residue at this position, while KN3829 encodes a threonine. Introduction of an NS3-T249P mutation in the KN3829 genetic background significantly increased virulence and mortality; however, peak viremia and mortality were lower than those of NY99. In order to elucidate the viral genetic basis for phenotype variations exclusive of the NS3-249 polymorphism, chimeric NY99/KN3829 viruses were created. We show herein that differences in the NS1-2B region contribute to avian pathogenicity in a manner that is independent of and additive with the NS3-249 mutation. Additionally, NS1-2B residues were found to alter temperature sensitivity when grown in avian cells.

  2. Higher temperature variability reduces temperature sensitivity of vegetation growth in Northern Hemisphere (United States)

    Wu, Xiuchen; Liu, Hongyan; Li, Xiaoyan; Piao, Shilong; Ciais, Philippe; Guo, Weichao; Yin, Yi; Poulter, Ben; Peng, Changhui; Viovy, Nicolas; Vuichard, Nicolas; Wang, Pei; Huang, Yongmei


    Interannual air temperature variability has changed over some regions in Northern Hemisphere (NH), accompanying with climate warming. However, whether and to what extent it regulates the interannual sensitivity of vegetation growth to temperature variability (i.e., interannual temperature sensitivity)—one central issue in understanding and predicting the responses of vegetation growth to changing climate—still remains poorly quantified and understood. Here we quantify the relationships between the interannual temperature sensitivity of mean growing-season (April-October) normalized difference vegetation index (NDVI) and ecosystem model simulations of gross primary productivity (GPP), and variability in mean growing-season temperature for forest, shrub, and grass over NH. We find that higher interannual variability in mean growing-season temperature leads to consistent decrease in interannual temperature sensitivity of mean growing-season NDVI among all vegetation types but not in model simulations of GPP. Drier condition associates with 130 ± 150% further decrease in interannual temperature sensitivity of mean growing-season NDVI by temperature variability in forest and shrub. These results illustrate that varying temperature variability can significantly regulate the interannual temperature sensitivity of vegetation growth over NH, interacted with drought variability and nonlinear responses of photosynthesis to temperature. Our findings call for an improved characterization of the nonlinear effects of temperature variability on vegetation growth within global ecosystem models.

  3. Coupling behavior of the pH/temperature sensitive hydrogels for the inhomogeneous and homogeneous swelling (United States)

    Mazaheri, H.; Baghani, M.; Naghdabadi, R.; Sohrabpour, S.


    In this work, a model is developed to continuously predict homogeneous and inhomogeneous swelling behavior of pH/temperature sensitive PNIPAM hydrogels. Employing the model, homogeneous swelling of the pH/temperature sensitive hydrogel is investigated for free and biaxial constrained swelling cases. Comparing the model results with the experimental data available in the literature, the validity of the model is confirmed. The model is then employed to investigate inhomogeneous swelling of a spherical shell on a hard core both analytically and numerically for pH or temperature variations. In this regard, numerical tools are developed via preparing a user defined subroutine in ABAQUS software. Then, the complicated problem of contact between the hydrogel shell and a micro-channel with rigid walls is also investigated. Considering the results, we can say that the model is applicable for solving engineering boundary value problem of pH/temperature sensitive hydrogels.

  4. Rapid, Simple and Cost-Effective Molecular Method to Differentiate the Temperature Sensitive (ts+) MS-H Vaccine Strain and Wild-Type Mycoplasma synoviae Isolates (United States)

    Kreizinger, Zsuzsa; Sulyok, Kinga Mária; Pásztor, Alexandra; Erdélyi, Károly; Felde, Orsolya; Povazsán, János; Kőrösi, László; Gyuranecz, Miklós


    Mycoplasma synoviae infection in chickens and turkeys can cause respiratory disease, infectious synovitis and eggshell apex abnormality; thus it is an economically important pathogen. Control of M. synoviae infection comprises eradication, medication or vaccination. The differentiation of the temperature sensitive (ts+) MS-H vaccine strain from field isolates is crucial during vaccination programs. Melt-curve and agarose gel based mismatch amplification mutation assays (MAMA) are provided in the present study to distinguish between the ts+ MS-H vaccine strain, its non-temperature sensitive re-isolates and wild-type M. synoviae isolates based on the single nucleotide polymorphisms at nt367 and nt629 of the obg gene. The two melt-MAMAs and the two agarose-MAMAs clearly distinguish the ts+ MS-H vaccine strain genotype from its non-temperature sensitive re-isolate genotype and wild-type M. synoviae isolate genotype, and no cross-reactions with other Mycoplasma species infecting birds occur. The sensitivity of the melt-MAMAs and agarose-MAMAs was 103 and 104 copy numbers, respectively. The assays can be performed directly on clinical samples and they can be run simultaneously at the same annealing temperature. The assays can be performed in laboratories with limited facilities, using basic real-time PCR machine or conventional thermocycler coupled with agarose gel electrophoresis. The advantages of the described assays compared with previously used methods are simplicity, sufficient sensitivity, time and cost effectiveness and specificity. PMID:26207635

  5. Isolation of temperature-sensitive mutants of 16 S rRNA in Escherichia coli

    DEFF Research Database (Denmark)

    Triman, K; Becker, E; Dammel, C


    Temperature-sensitive mutants have been isolated following hydroxylamine mutagenesis of a plasmid containing Escherichia coli rRNA genes carrying selectable markers for spectinomycin resistance (U1192 in 16 S rRNA) and erythromycin resistance (G2058 in 23 S rRNA). These antibiotic resistance...

  6. Temperature sensitivity of soil microbial communities: An application of macromolecular rate theory to microbial respiration (United States)

    Alster, Charlotte J.; Koyama, Akihiro; Johnson, Nels G.; Wallenstein, Matthew D.; von Fischer, Joseph C.


    There is compelling evidence that microbial communities vary widely in their temperature sensitivity and may adapt to warming through time. To date, this sensitivity has been largely characterized using a range of models relying on versions of the Arrhenius equation, which predicts an exponential increase in reaction rate with temperature. However, there is growing evidence from laboratory and field studies that observe nonmonotonic responses of reaction rates to variation in temperature, indicating that Arrhenius is not an appropriate model for quantitatively characterizing temperature sensitivity. Recently, Hobbs et al. (2013) developed macromolecular rate theory (MMRT), which incorporates thermodynamic temperature optima as arising from heat capacity differences between isoenzymes. We applied MMRT to measurements of respiration from soils incubated at different temperatures. These soils were collected from three grassland sites across the U.S. Great Plains and reciprocally transplanted, allowing us to isolate the effects of microbial community type from edaphic factors. We found that microbial community type explained roughly 30% of the variation in the CO2 production rate from the labile C pool but that temperature and soil type were most important in explaining variation in labile and recalcitrant C pool size. For six out of the nine soil × inoculum combinations, MMRT was superior to Arrhenius. The MMRT analysis revealed that microbial communities have distinct heat capacity values and temperature sensitivities sometimes independent of soil type. These results challenge the current paradigm for modeling temperature sensitivity of soil C pools and understanding of microbial enzyme dynamics.

  7. Investigation of Temperature Sensitivity of a Polymer-Overlaid Microfiber Mach-Zehnder Interferometer. (United States)

    Han, Young-Geun


    The temperature sensitivity of the free spectral range (FSR) for a polymer-overlaid microfiber Mach-Zehnder interferometer (MZI) is investigated both theoretically and experimentally. The waist diameter of the optical microfiber can be controlled to alter the thermal expansion and optic properties of the polymer-coated MZI. Inserting an optical microfiber with a strong evanescent field into the MZI, a low index polymer with high thermal characteristics is deposited on the surface of the microfibers to realize a polymer-overlaid microfiber MZI. It was found that the thermal expansion factor in the proposed MZI plays an important role in the temperature sensitivity of the FSR. The temperature sensitivity of the polymer-overlaid microfiber MZI is improved, which is measured to be -8.29 nm/°C at 25 °C. The optical transmission spectrum of the polymer-overlaid microfiber MZI is converted to the spatial frequency spectrum via fast Fourier transform. The temperature sensitivity of the spatial frequency in the proposed polymer-overlaid MZI is estimated to be 18.31 pm(-1) °C(-1), which is 17 times higher than that of the microfiber MZI without polymer coating (1.04 pm(-1) °C(-1)).

  8. Investigation of Temperature Sensitivity of a Polymer-Overlaid Microfiber Mach-Zehnder Interferometer

    Directory of Open Access Journals (Sweden)

    Young-Geun Han


    Full Text Available The temperature sensitivity of the free spectral range (FSR for a polymer-overlaid microfiber Mach-Zehnder interferometer (MZI is investigated both theoretically and experimentally. The waist diameter of the optical microfiber can be controlled to alter the thermal expansion and optic properties of the polymer-coated MZI. Inserting an optical microfiber with a strong evanescent field into the MZI, a low index polymer with high thermal characteristics is deposited on the surface of the microfibers to realize a polymer-overlaid microfiber MZI. It was found that the thermal expansion factor in the proposed MZI plays an important role in the temperature sensitivity of the FSR. The temperature sensitivity of the polymer-overlaid microfiber MZI is improved, which is measured to be −8.29 nm/°C at 25 °C. The optical transmission spectrum of the polymer-overlaid microfiber MZI is converted to the spatial frequency spectrum via fast Fourier transform. The temperature sensitivity of the spatial frequency in the proposed polymer-overlaid MZI is estimated to be 18.31 pm−1 °C−1, which is 17 times higher than that of the microfiber MZI without polymer coating (1.04 pm−1 °C−1.

  9. Preparation and anti-bacterial properties of a temperature sensitive gel containing silver nanoparticles (United States)

    The purpose of this study was to prepare a novel temperature-sensitive spray gel containing silver nanoparticles and investigate its anti-bacterial properties in vitro. Methods: The aqueous complex gel was prepared by Pluronic F127 (18-22%) and Pluronic F68 (3-9%) through a cold method to obtain a p...

  10. Suppression of temperature-sensitive chromosome replication of an Escherichia coli dnaX(Ts) mutant by reduction of initiation efficiency. (United States)

    Blinkova, Alexandra; Hermandson, Mary Jo; Walker, James R


    Temperature sensitivity of DNA polymerization and growth of a dnaX(Ts) mutant is suppressible at 39 to 40 degrees C by mutations in the initiator gene, dnaA. These suppressor mutations concomitantly cause initiation inhibition at 20 degrees C and have been designated Cs,Sx to indicate both phenotypic characteristics of cold-sensitive initiation and suppression of dnaX(Ts). One dnaA(Cs,Sx) mutant, A213D, has reduced affinity for ATP, and two mutants, R432L and T435K, have eliminated detectable DnaA box binding in vitro. Two models have explained dnaA(Cs,Sx) suppression of dnaX, which codes for both the tau and gamma subunits of DNA polymerase III. The initiation deficiency model assumes that reducing initiation efficiency allows survival of the dnaX(Ts) mutant at the somewhat intermediate temperature of 39 to 40 degrees C by reducing chromosome content per cell, thus allowing partially active DNA polymerase III to complete replication of enough chromosomes for the organism to survive. The stabilization model is based on the idea that DnaA interacts, directly or indirectly, with polymerization factors during replication. We present five lines of evidence consistent with the initiation deficiency model. First, a dnaA(Cs,Sx) mutation reduced initiation frequency and chromosome content (measured by flow cytometry) and origin/terminus ratios (measured by real-time PCR) in both wild-type and dnaX(Ts) strains growing at 39 and 34 degrees C. These effects were shown to result specifically from the Cs,Sx mutations, because the dnaX(Ts) mutant is not defective in initiation. Second, reduction of the number of origins and chromosome content per cell was common to all three known suppressor mutations. Third, growing the dnaA(Cs,Sx) dnaX(Ts) strain on glycerol-containing medium reduced its chromosome content to one per cell and eliminated suppression at 39 degrees C, as would be expected if the combination of poor carbon source, the Cs,Sx mutation, the Ts mutation, and the 39

  11. Pressure- and Temperature-Sensitive Paint at 0.3-m Transonic Cryogenic Tunnel (United States)

    Watkins, A. Neal; Leighty, Bradley D.; Lipford, William E.; Goodman, Kyle Z.


    Recently both Pressure- and Temperature-Sensitive Paint experiments were conducted at cryogenic conditions in the 0.3-m Transonic Cryogenic Tunnel at NASA Langley Research Center. This represented a re-introduction of the techniques to the facility after more than a decade, and provided a means to upgrade the measurements using newer technology as well as demonstrate that the techniques were still viable in the facility. Temperature-Sensitive Paint was employed on a laminar airfoil for transition detection and Pressure-Sensitive Paint was employed on a supercritical airfoil. This report will detail the techniques and their unique challenges that need to be overcome in cryogenic environments. In addition, several optimization strategies will also be discussed.

  12. Nonwoven supported temperature-sensitive poly(N-isopropylacrylamide)/polyurethane copolymer hydrogel with antibacterial activity. (United States)

    Liu, Baohua; Hu, Jinlian; Meng, Qinghao


    This article is focused on the study of the antibacterial activity of temperature sensitive poly(N-isopropylacrylamide/polyurethane (PNIPAAm/PU) hydrogel grafted nonwoven fabrics with chitosan modification. A series of temperature sensitive hydrogel grafted nonwoven fabrics with different N-isopropylacrylamide/polyurethane (NIPAAm/PU) feeding ratios have been synthesized by using ammonium persulfate (APS) as initiator and N,N,N',N'-tetramethyl-ethane-1,2-diamine (TEMED) as accelerator. FTIR and XPS were used to examine the surface modification of chitosan. The phase transition temperature of hydrogel grafted nonwoven fabrics was about 32 degrees C by DSC. S. aureus and E. coli were used to evaluate the antibacterial efficiency of the fabric composite. After chitosan modification, the hydrogel grafted nonwoven cellulose fabrics demonstrates an antibacterial activity to S. aureus. and E. coli and the antibacterial efficiency is about 80%.

  13. Imaging heat transfer processes in a fluid with temperature sensitive paint (United States)

    Huang, Jun; Liu, Tianshu; Luo, Weili


    The temperature profile inside a fluid was imaged by temperature sensitive paint in a quasi one-dimensional cell, where temperature gradients were established by heating on one side of the sample and cooling on the other. Similar experiment was performed on colloids consisting nanoparticles suspended in solvent. The change of the profile for different heat-transfer processes as functions of time will be discussed.

  14. Soil organic matter decomposition and temperature sensitivity after forest fire in permafrost regions in Canada (United States)

    Aaltonen, Heidi; Palviainen, Marjo; Köster, Kajar; Berninger, Frank; Pumpanen, Jukka


    On the Northern Hemisphere, 24% of soils are underlain by permafrost. These soils contain 50% of the global soil carbon pool. The Northern Hemisphere is also the region which is predicted to be most affected by climate warming and this causes uncertainties over the future of the permafrost. It has been estimated that 25% of permafrost might thaw by 2100, exposing previously frozen carbon pools to decomposition. In addition, global warming is expected to cause increase in the frequency of wild fires, which further increase permafrost melting by removing the insulating organic surface layer. The amount of released soil carbon from permafrost soils after forest fire is affected by degradability and temperature sensitivity of the soil organic matter, as well as soil depth and the stage of succession. Yet the common effect of these factors remains unclear. We studied how soil respiration and its temperature sensitivity (Q10) vary in different depths and within time by taking soil samples from different fire chronosequence areas (burned 3, 25, 46 and 100 years ago) from permafrost region in Northern Canada (Yukon and Northwest Territories, along Dempster Highway). The samples from three different depths (5, 10 and 30 cm) were incubated in four different temperatures (1, 7, 13 and 19°C) over 24h. Our results showed that the CO2 fluxes followed the stages of succession, with recently burned sites having lowest rates. The organic matter at 5 cm depth proved to be more labile and temperature sensitive than in deeper depths. The Q10 values, however, did not differ between sites, excluding 30 cm at the most recently burned site that had a significantly higher Q10 value than the other sites. The results implicate that heterotrophic soil respiration decreases on permafrost regions during the first stages after forest fire. At the same time the temperature sensitivity in deeper soil layers may increase.

  15. Temperature-Sensitive Plant Cells with Shunted Indole-3-Acetic Acid Conjugation. (United States)

    Oetiker, J. H.; Aeschbacher, G.


    Cells of henbane (Hyoscyamus muticus L.) grow indefinitely in culture without exogenous auxin. Cells of its temperature-sensitive variant XIIB2 grow like the wild type at 26[deg]C but die rapidly at 33[deg]C unless auxin is added to the medium. Despite this temperature-sensitive auxin auxotrophy, XIIB2 produces wild-type amounts of indole-3-acetic acid (IAA). IAA is the predominant auxin and is important for plant growth and development. Since the IAA production of the variant is functional, we investigated whether the synthesis or degradation of IAA metabolites, possibly active auxins themselves, is altered. The IAA metabolites were IAA-aspartate (IAAsp) and IAA-glucose. The wild type converted IAA mainly to IAAsp, whereas the variant produced mainly IAA-glucose. Exogenous auxin corrected the shunted IAA metabolism of the variant. The half-life of labeled IAAsp in the variant was reduced 21-fold, but in the presence of exogenous auxin it was not different from the wild type. The temperature sensitivity of XIIB2 was also corrected by supplying IAAsp. Pulse-chase experiments revealed that henbane rapidly metabolizes IAAsp to compounds not identical to IAA. The data show that the variant XIIB2 is a useful tool to study the function of IAA conjugates to challenge the popular hypothesis that IAA conjugates are merely slow-release storage forms of IAA. PMID:12223777

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  3. Analysis of remineralisation, lability, temperature sensitivity and structural composition of organic matter from the upper ocean (United States)

    Bendtsen, Jørgen; Hilligsøe, Karen Marie; Hansen, Jørgen L. S.; Richardson, Katherine


    Organic carbon (OC) synthesised by plankton is exported out of the surface layer as particulate (POC) and dissolved (DOC) organic carbon. This 'biological pump' constitutes a major pathway in the global marine carbon cycle, each year exporting about 10 Pg C into the ocean interior, where it is subsequently remineralised via biological decomposition. Remineralised inorganic nutrients and carbon are, ultimately, again brought to the surface by advection and turbulent mixing which closes the OC-cycle in the upper ocean. Thus, remineralisation rates of OC are a critical component of the biological pump. These rates are regulated by the lability of the material and the environmental conditions in the ambient water. Temperature is particularly important in regulating the rate of microbial respiration and, thus, remineralisation rates. A significant temperature dependence of the microbial metabolic activity in the ocean interior is expected, as this is a feature observed elsewhere in the biosphere. Such temperature dependence of microbial remineralisation of POC and DOC will alter the amount of material available for transport by the biological pump to the deep ocean. Very few studies on the lability of OC and temperature sensitivity of microbial degradation processes in the mesopelagic zone (∼100-1000 m) have, to date, been carried out. Here, we present a comprehensive new experimental data set from all major ocean basins and quantify remineralisation rates of OC and their temperature sensitivity in long-term incubations of water from the upper 350 m. Microbial respiration was measured by non-invasive oxygen optodes and oxygen consumption was used as a constraint for determining the remineralisation rates and temperature sensitivity by two complementary methods. First, we analysed the oxygen consumption from a multi-component OC-model where the concentration, remineralisation rates and temperature sensitivity of two bio-available (labile) pools of organic carbon were

  4. Analysis of the essentiality of ROM2 genes in the pathogenic yeasts Candida glabrata and Candida albicans using temperature-sensitive mutants. (United States)

    Kanno, T; Takekawa, D; Miyakawa, Y


    To analyse the essentiality of the ROM2 genes originating from the pathogenic yeasts Candida glabrata and Candida albicans by using temperature-sensitive (ts) mutants. Based on the general concepts that ts mutations are generated by virtue of point mutation within essential genes, we have previously established a novel method (termed 'ETS system' for screening and identification of essential genes using ts mutants of C. glabrata). According to this ETS system, the present study successfully identified a putative C. glabrata ROM2 homologue as an essential gene that complements its point mutation (Cys-1275/Tyr substitution). The C. albicans ROM2 mutant (Cys-1281/Tyr), constructed patterned after this point mutation, also displayed ts phenotype. Both ts mutants recovered colony-forming ability, with concomitant suppression of lysis phenotype, at the elevated temperature in the presence of 1 mol l(-1) sorbitol as an osmotic stabilizer. Sequence alignment revealed that human genome possesses relatively low homology against Rom2 homologues, which are highly conserved among yeast species. ROM2 genes of C. glabrata and C. albicans are essential for viability, probably involved in cell wall integrity. ROM2 genes essential for both Candida species may be a potentially useful antifungal targets from chemotherapeutic viewpoint. © 2015 The Society for Applied Microbiology.

  5. Soil warming increases metabolic quotients of soil microorganisms without changes in temperature sensitivity of soil respiration (United States)

    Marañón-Jiménez, Sara; Soong, Jenniffer L.; Leblans, Niki I. W.; Sigurdsson, Bjarni D.; Dauwe, Steven; Fransen, Erik; Janssens, Ivan A.


    Increasing temperatures can accelerate soil organic matter (SOM) decomposition and release large amounts of CO2 to the atmosphere, potentially inducing climate change feedbacks. Alterations to the temperature sensitivity and metabolic pathways of soil microorganisms in response to soil warming can play a key role in these soil carbon (C) losses. Here, we present results of an incubation experiment using soils from a geothermal gradient in Iceland that have been subjected to different intensities of soil warming (+0, +1, +3, +5, +10 and +20 °C above ambient) over seven years. We hypothesized that 7 years of soil warming would led to a depletion of labile organic substrates, with a subsequent decrease of the "apparent" temperature sensitivity of soil respiration. Associated to this C limitation and more sub-optimal conditions for microbial growth, we also hypothesized increased microbial metabolic quotients (soil respiration per unit of microbial biomass), which is associated with increases in the relative amount of C invested into catabolic pathways along the warming gradient. Soil respiration and basal respiration rates decreased with soil warming intensity, in parallel with a decline in soil C availability. Contrasting to our first hypothesis, we did not detect changes in the temperature sensitivity of soil respiration with soil warming or on the availability of nutrients and of labile C substrates at the time of incubation. However, in agreement to our second hypothesis, microbial metabolic quotients (soil respiration per unit of microbial biomass) increased at warmer temperatures, while the C retained in biomass decreased as substrate became limiting. Long-term (7 years) temperature increases thus triggered a change in the metabolic functioning of the soil microbial communities towards increasing energy costs for maintenance or resource acquisition, thereby lowering the capacity of C retention and stabilization of warmed soils. These results highlight the need

  6. Accuracy of critical-temperature sensitivity coefficients predicted by multilayered composite plate theories (United States)

    Noor, Ahmed K.; Burton, Scott


    An assessment is made of the accuracy of the critical-temperature sensitivity coefficients of multilayered plates predicted by different modeling approaches, based on two-dimensional shear-deformation theories. The sensitivity coefficients considered measure the sensitivity of the critical temperatures to variations in different lamination and material parameters of the plate. The standard of comparison is taken to be the sensitivity coefficients obtained by the three-dimensional theory of thermoelasticity. Numerical studies are presented showing the effects of variation in the geometric and lamination parameters of the plate on the accuracy of both the sensitivity coefficients and the critical temperatures predicted by the different modeling approaches.

  7. Mars Thermospheric Temperature Sensitivity to Solar EUV Forcing from the MAVEN EUV Monitor (United States)

    Thiemann, Ed; Eparvier, Francis; Andersson, Laila; Pilinski, Marcin; Chamberlin, Phillip; Fowler, Christopher; MAVEN Extreme Ultraviolet Monitor Team, MAVEN Langmuir Probe and Waves Team


    Solar extreme ultraviolet (EUV) radiation is the primary heat source for the Mars thermosphere, and the primary source of long-term temperature variability. The Mars obliquity, dust cycle, tides and waves also drive thermospheric temperature variability; and it is important to quantify the role of each in order to understand processes in the upper atmosphere today and, ultimately, the evolution of Mars climate over time. Although EUV radiation is the dominant heating mechanism, accurately measuring the thermospheric temperature sensitivity to EUV forcing has remained elusive, in part, because Mars thermospheric temperature varies dramatically with latitude and local time (LT), ranging from 150K on the nightside to 300K on the dayside. It follows that studies of thermospheric variability must control for location.Instruments onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter have begun to characterize thermospheric temperature sensitivity to EUV forcing. Bougher et al. [2017] used measurements from the Imaging Ultraviolet Spectrograph (IUVS) and the Neutral Gas and Ion Mass Spectrometer (NGIMS) to characterize solar activity trends in the thermosphere with some success. However, aside from restricting measurements to solar zenith angles (SZAs) below 75 degrees, they were unable to control for latitude and LT because repeat-track observations from either instrument were limited or unavailable.The MAVEN EUV Monitor (EUVM) has recently demonstrated the capability to measure thermospheric density from 100 to 200 km with solar occultations of its 17-22 nm channel. These new density measurements are ideal for tracking the long-term thermospheric temperature variability because they are inherently constrained to either 06:00 or 18:00 LT, and the orbit has precessed to include a range of ecliptic latitudes, a number of which have been revisited multiple times over 2.5 years. In this study we present, for the first-time, measurements of thermospheric

  8. Rendering poly(amidoamine) or poly(propylenimine) dendrimers temperature sensitive. (United States)

    Haba, Yasuhiro; Harada, Atsushi; Takagishi, Toru; Kono, Kenji


    The poly(amidoamine) dendrimers having terminal isobutyramide (IBAM) groups were prepared by the reaction of isobutyric acid and the amine-terminated poly(amidoamine) dendrimers with generations (G) of 2 to 5 by using a condensing agent, 1,3-dicyclohexylcarbodiimide. 1H and 13C NMR revealed that an IBAM group was attached to essentially every chain end of the dendrimers. While the IBAM-terminated G2 dendrimer was soluble in water, the IBAM-terminated G3, G4, and G5 dendrimers exhibited the lower critical solution temperatures (LCSTs) at 75, 61, and 43 degrees C, respectively. Because the density of the terminal IBAM groups in the periphery of the dendrimer progressively increases with increasing dendrimer generation, the interaction of the IBAM groups might take place more efficiently, resulting in a remarkable decrease in the LCST. In addition, attachment of IBAM groups to poly(propylenimine) dendrimers could give the temperature-sensitive property, indicating that this is an efficient method to render dendrimers temperature sensitive.

  9. Changes in spring arrival dates and temperature sensitivity of migratory birds over two centuries (United States)

    Kolářová, Eva; Matiu, Michael; Menzel, Annette; Nekovář, Jiří; Lumpe, Petr; Adamík, Peter


    Long-term phenological data have been crucial at documenting the effects of climate change in organisms. However, in most animal taxa, time series length seldom exceeds 35 years. Therefore, we have limited evidence on animal responses to climate prior to the recent warm period. To fill in this gap, we present time series of mean first arrival dates to Central Europe for 13 bird species spanning 183 years (1828-2010). We found a uniform trend of arrival dates advancing in the most recent decades (since the late 1970s). Interestingly, birds were arriving earlier during the cooler early part of the nineteenth century than in the recent warm period. Temperature sensitivity was slightly stronger in the warmest 30-year period (-1.70 ± SD 0.47 day °C-1) than in the coldest period (-1.42 ± SD 0.89 day °C-1); however, the difference was not statistically significant. In the most recent decades, the temperature sensitivity of both short- and long-distance migrants significantly increased. Our results demonstrate how centennial time series can provide a much more comprehensive perspective on avian responses to climate change.

  10. A temperature sensitive VSV identifies L protein residues that affect transcription but not replication. (United States)

    Galloway, Summer E; Wertz, Gail W


    To investigate the polymerase components selectively involved in transcription versus replication of vesicular stomatitis virus (VSV), we sequenced the polymerase gene of a conditionally RNA defective, temperature sensitive VSV: ts(G)114, which has a phenotype upon shift from permissive to non-permissive temperature of shut-down of mRNA transcription and unaffected genome replication. Sequence analysis of the ts(G)114 L gene identified three altered amino acid residues in the L protein. These three changes were specifically engineered individually and in combinations into a functional cDNA clone encoding the VSV genome and tested for association with the temperature sensitive and RNA defective phenotypes in the background of recovered engineered viruses. The data presented in this study show a specific amino acid substitution in domain II of the VSV L protein that significantly affects total RNA synthesis, but when in combination with two additional amino acid substitutions identified in the ts(G)114 L protein, leads to a specific reduction in mRNA transcription, but not replication.

  11. Temperature-sensitive SV40-immortalized rat middle ear epithelial cells. (United States)

    Toyama, Katsuhiro; Kim, Youngki; Paparella, Michael M; Lin, Jizhen


    The proliferation and differentiation of middle ear epithelial cells are essential in both normal and diseased middle ears. The normal situation involves physiologic growth and renewal of the epithelium, and the diseased situation involves pathological changes of the epithelium such as mucous cell metaplasia and ciliated cell proliferation in otitis media. In this study, we used a temperature-sensitive large T antigen (the SV40 mutant) to transduce and immortalize the primary culture of middle ear epithelial cells. SV40-immortalized middle ear epithelial cells have been cultured for more than 50 passages and are stable morphologically. Their nonimmortalized parent cells died at the second passage. Immortalized middle ear epithelial cells carrying the SV40 mutant show a monolayer, cobblestonelike morphology. The cell line expresses characteristic middle ear mucosal molecules such as mucins, keratins, and collagens. It also responds to temperature changes; namely, cells proliferate at 33 degrees C, when the SV40 antigen is active, and differentiate at 39 degrees C, when the SV40 antigen is inactive. Therefore, we conclude that a temperature-sensitive middle ear epithelial cell line has successfully been established.

  12. Higher climatological temperature sensitivity of soil carbon in cold than warm climates (United States)

    Koven, Charles D.; Hugelius, Gustaf; Lawrence, David M.; Wieder, William R.


    The projected loss of soil carbon to the atmosphere resulting from climate change is a potentially large but highly uncertain feedback to warming. The magnitude of this feedback is poorly constrained by observations and theory, and is disparately represented in Earth system models (ESMs). To assess the climatological temperature sensitivity of soil carbon, we calculate apparent soil carbon turnover times that reflect long-term and broad-scale rates of decomposition. Here, we show that the climatological temperature control on carbon turnover in the top metre of global soils is more sensitive in cold climates than in warm climates and argue that it is critical to capture this emergent ecosystem property in global-scale models. We present a simplified model that explains the observed high cold-climate sensitivity using only the physical scaling of soil freeze-thaw state across climate gradients. Current ESMs fail to capture this pattern, except in an ESM that explicitly resolves vertical gradients in soil climate and carbon turnover. An observed weak tropical temperature sensitivity emerges in a different model that explicitly resolves mineralogical control on decomposition. These results support projections of strong carbon-climate feedbacks from northern soils and demonstrate a method for ESMs to capture this emergent behaviour.

  13. Factors influencing the temperature sensitivity of PMMA based optical fiber Bragg gratings (United States)

    Zhang, Wei; Webb, David J.


    The Bragg wavelength of a PMMA based fiber grating is determined by the effective core index and the grating pitch, which, in temperature sensing, depend on the thermo-optic and thermal expansion coefficients of PMMA. These two coefficients are a function of surrounding temperature and humidity. Amorphous polymers including PMMA exhibit a certain degree of anisotropic thermal expansion. The anisotropic nature of expansion mainly depends on the polymer processing history. The expansion coefficient is believed to be lower in the direction of the molecular orientation than in the direction perpendicular to the draw direction. Such anisotropic behavior of polymers can be expected in drawn PMMA based optical fiber, and will lead to a reduced thermal expansion coefficient and larger temperature sensitivity than would be the case were the fiber to be isotropic. Extensive work has been carried out to identify these factors. The temperature responses of gratings have been measured at different relative humidity. Gratings fabricated on annealed and non-annealed PMMA optical fibers are used to compare the sensitivity performance as annealing is considered to be able to mitigate the anisotropic effect in PMMA optical fiber. Furthermore an experiment has been designed to eliminate the thermal expansion contribution to the grating wavelength change, leading to increased temperature sensitivity and improved response linearity.

  14. Influence of temperature on the formation and encapsulation of gold nanoparticles using a temperature-sensitive template

    Directory of Open Access Journals (Sweden)

    Noel Peter Bengzon Tan


    Full Text Available This data article describes the synthesis of temperature-sensitive and amine-rich microgel particle as a dual reductant and template to generate smart gold/polymer nanocomposite particle. TEM images illustrate the influence of reaction temperature on the formation and in-site encapsulation of gold nanoparticles using the temperature-sensitive microgel template. Thermal stability of the resultant gold/polymer composite particles was also examined.

  15. Cold-Adapted Viral Attenuation (CAVA: Highly Temperature Sensitive Polioviruses as Novel Vaccine Strains for a Next Generation Inactivated Poliovirus Vaccine.

    Directory of Open Access Journals (Sweden)

    Barbara P Sanders


    Full Text Available The poliovirus vaccine field is moving towards novel vaccination strategies. Withdrawal of the Oral Poliovirus Vaccine and implementation of the conventional Inactivated Poliovirus Vaccine (cIPV is imminent. Moreover, replacement of the virulent poliovirus strains currently used for cIPV with attenuated strains is preferred. We generated Cold-Adapted Viral Attenuation (CAVA poliovirus strains by serial passage at low temperature and subsequent genetic engineering, which contain the capsid sequences of cIPV strains combined with a set of mutations identified during cold-adaptation. These viruses displayed a highly temperature sensitive phenotype with no signs of productive infection at 37°C as visualized by electron microscopy. Furthermore, decreases in infectious titers, viral RNA, and protein levels were measured during infection at 37°C, suggesting a block in the viral replication cycle at RNA replication, protein translation, or earlier. However, at 30°C, they could be propagated to high titers (9.4-9.9 Log10TCID50/ml on the PER.C6 cell culture platform. We identified 14 mutations in the IRES and non-structural regions, which in combination induced the temperature sensitive phenotype, also when transferred to the genomes of other wild-type and attenuated polioviruses. The temperature sensitivity translated to complete absence of neurovirulence in CD155 transgenic mice. Attenuation was also confirmed after extended in vitro passage at small scale using conditions (MOI, cell density, temperature anticipated for vaccine production. The inability of CAVA strains to replicate at 37°C makes reversion to a neurovirulent phenotype in vivo highly unlikely, therefore, these strains can be considered safe for the manufacture of IPV. The CAVA strains were immunogenic in the Wistar rat potency model for cIPV, inducing high neutralizing antibody titers in a dose-dependent manner in response to D-antigen doses used for cIPV. In combination with the

  16. Global synthesis of the temperature sensitivity of leaf litter breakdown in streams and rivers. (United States)

    Follstad Shah, Jennifer J; Kominoski, John S; Ardón, Marcelo; Dodds, Walter K; Gessner, Mark O; Griffiths, Natalie A; Hawkins, Charles P; Johnson, Sherri L; Lecerf, Antoine; LeRoy, Carri J; Manning, David W P; Rosemond, Amy D; Sinsabaugh, Robert L; Swan, Christopher M; Webster, Jackson R; Zeglin, Lydia H


    Streams and rivers are important conduits of terrestrially derived carbon (C) to atmospheric and marine reservoirs. Leaf litter breakdown rates are expected to increase as water temperatures rise in response to climate change. The magnitude of increase in breakdown rates is uncertain, given differences in litter quality and microbial and detritivore community responses to temperature, factors that can influence the apparent temperature sensitivity of breakdown and the relative proportion of C lost to the atmosphere vs. stored or transported downstream. Here, we synthesized 1025 records of litter breakdown in streams and rivers to quantify its temperature sensitivity, as measured by the activation energy (Ea , in eV). Temperature sensitivity of litter breakdown varied among twelve plant genera for which Ea could be calculated. Higher values of Ea were correlated with lower-quality litter, but these correlations were influenced by a single, N-fixing genus (Alnus). Ea values converged when genera were classified into three breakdown rate categories, potentially due to continual water availability in streams and rivers modulating the influence of leaf chemistry on breakdown. Across all data representing 85 plant genera, the Ea was 0.34 ± 0.04 eV, or approximately half the value (0.65 eV) predicted by metabolic theory. Our results indicate that average breakdown rates may increase by 5-21% with a 1-4 °C rise in water temperature, rather than a 10-45% increase expected, according to metabolic theory. Differential warming of tropical and temperate biomes could result in a similar proportional increase in breakdown rates, despite variation in Ea values for these regions (0.75 ± 0.13 eV and 0.27 ± 0.05 eV, respectively). The relative proportions of gaseous C loss and organic matter transport downstream should not change with rising temperature given that Ea values for breakdown mediated by microbes alone and microbes plus detritivores were similar at the global

  17. Numerical Investigation on Heat and Flow Characteristics of Temperature-Sensitive Ferrofluid in a Square Cavity

    Directory of Open Access Journals (Sweden)

    Moo-Yeon Lee


    Full Text Available The objective of this paper is numerically to study the heat and flow characteristics of temperature-sensitive ferrofluid in the square cavity with and without the magnetic intensity. The numerical model was developed to predict the behavior of the ferrofluid using finite element method (FEM and showed good agreement with the existing data within 5% at all Rayleigh number ranges from 103 to 106. Natural convection and heat transfer characteristics of the ferrofluids within the tested cavity were found to depend on both magnetic intensity and magnetic volume fractions of magnetite. In addition, the mean Nusselt numbers and mean velocity of the ferrofluid in a square cavity were increased with the rise of the magnetic intensities and increased by 23.2% and 143.7%, respectively, at both magnetic intensity of H = 10000 A/m and the elapsed time of t = 30000 seconds.

  18. Highly sensitive fiber loop ringdown strain sensor with low temperature sensitivity (United States)

    Ghimire, Maheshwar; Wang, Chuji


    We report a highly sensitive strain sensor with low temperature sensitivity based on the fiber loop ringdown technique. An innovative approach that employs a micro air-gap as the strain sensor head is described. The sensor has demonstrated the static strain sensitivity of 0.26 µs/µɛ, corresponding to the detection limit of 65 nɛ with the low temperature cross sensitivity of 37 nɛ/°C. This is the highest static strain sensitivity achieved without using a combination of fiber optic sensing components, such as fiber Bragg gratings or Fabry-Perot interferometers. Moreover, the sensor design allows the strain sensitivity and measuring range to be adjusted by changing the length of the sensor.


    Directory of Open Access Journals (Sweden)



    Full Text Available The present work aims at investigating the temperature sensitive fluoro-optic behaviour of Cu-activated strontium sulphide (SrS phosphors and its possible application in thermography. Accordingly, SrS (Cu phosphors have been synthesized and painted with the help of adhesive on silica substrate. The excitation and emission spectra of such phosphor coatings have been recorded at room temperature (25C. The temperature dependence of fluorescence intensity and the lifetime of phosphorescence have also been studied. From the systematic variation of these two parameters with temperature, it appears that these phosphors are good candidates for thermographic application, at least, in the temperature range of investigation (25-150C.

  20. Soil carbon storage and temperature sensitivity associated with shrub and graminoid vegetation in Kangerlussuaq, Greenland (United States)

    Bradley-Cook, J. I.; Petrenko, C. L.; Friedland, A. J.; Virginia, R. A.


    The Arctic tundra is experiencing rapid change, including warming temperatures, shrub expansion and shifts in precipitation patterns. Environmental conditions and vegetation cover are strong controls on soil carbon storage, respiration, and temperature sensitivity of decomposition. Temperature control of soil organic matter processing is particularly important in permafrost soils, which contain more than two times the carbon in the atmosphere and exist at the freeze-thaw threshold. To investigate sensitivity of decomposition to abiotic controls in a heterogeneous landscape, we conducted a laboratory incubation experiment on mineral soils collected in shrub and graminoid vegetation types near Kangerlussuaq, Greenland. We crossed temperature and moisture treatments and measured soil respiration rates over a seven-week incubation period. We measured soil carbon and nitrogen concentrations through elemental analysis and conducted sequential chemical extractions to measure carbon fractions and quantify soil carbon quality. Results show soils overlain by graminoids have higher carbon concentrations at shallow depth and respiration rates than soils overlain by shrub (mean ± 1 s.e. organic carbon concentration, 0-10 cm: graminoid = 68.7 ± 8.1 mg C * g soil-1, shrub = 48.8 ± 2.9 mg C * g soil-1). Temperature sensitivity was higher in graminoid soils, with no effect from soil moisture level. Carbon fractions and quality varied by vegetation type and profile depth. This study informs our understanding of the relationship between carbon quality and the temperature and moisture sensitivity of decomposition in western Greenland and demonstrates the importance of landscape heterogeneity in understanding soil carbon response to environmental drivers.

  1. Temperature sensitivity of microbial respiration of fine root litter in a temperate broad-leaved forest.

    Directory of Open Access Journals (Sweden)

    Naoki Makita

    Full Text Available The microbial decomposition respiration of plant litter generates a major CO2 efflux from terrestrial ecosystems that plays a critical role in the regulation of carbon cycling on regional and global scales. However, the respiration from root litter decomposition and its sensitivity to temperature changes are unclear in current models of carbon turnover in forest soils. Thus, we examined seasonal changes in the temperature sensitivity and decomposition rates of fine root litter of two diameter classes (0-0.5 and 0.5-2.0 mm of Quercus serrata and Ilex pedunculosa in a deciduous broad-leaved forest. During the study period, fine root litter of both diameter classes and species decreased approximately exponentially over time. The Q10 values of microbial respiration rates of root litter for the two classes were 1.59-3.31 and 1.28-6.27 for Q. serrata and 1.36-6.31 and 1.65-5.86 for I. pedunculosa. A significant difference in Q10 was observed between the diameter classes, indicating that root diameter represents the initial substrate quality, which may determine the magnitude of Q10 value of microbial respiration. Changes in these Q10 values were related to seasonal soil temperature patterns; the values were higher in winter than in summer. Moreover, seasonal variations in Q10 were larger during the 2-year decomposition period than the 1-year period. These results showed that the Q10 values of fine root litter of 0-0.5 and 0.5-2.0 mm have been shown to increase with lower temperatures and with the higher recalcitrance pool of the decomposed substrate during 2 years of decomposition. Thus, the temperature sensitivity of microbial respiration in root litter showed distinct patterns according to the decay period and season because of the temperature acclimation and adaptation of the microbial decomposer communities in root litter.

  2. Variations in the temperature sensitivity of spring leaf phenology from 1978 to 2014 in Mudanjiang, China (United States)

    Dai, Junhu; Xu, Yunjia; Wang, Huanjiong; Alatalo, Juha; Tao, Zexing; Ge, Quansheng


    Continuous long-term temperature sensitivity (ST) of leaf unfolding date (LUD) and main impacting factors in spring in the period 1978-2014 for 40 plant species in Mudanjiang, Heilongjiang Province, Northeast China, were analyzed by using observation data from the China Phenological Observation Network (CPON), together with the corresponding meteorological data from the China Meteorological Data Service Center. Temperature sensitivities, slopes of the regression between LUD and mean temperature during the optimum preseason (OP), were analyzed using 15-year moving window to determine their temporal trends. Major factors impacting ST were then chosen and evaluated by applying a random sampling method. The results showed that LUD was sensitive to mean temperature in a defined period before phenophase onset for all plant species analyzed. Over the period 1978-2014, the mean ST of LUD for all plant species was - 3.2 ± 0.49 days °C-1. The moving window analysis revealed that 75% of species displayed increasing ST of LUD, with 55% showing significant increases (P < 0.05). ST for the other 25% exhibited a decreasing trend, with 17% showing significant decreases (P < 0.05). On average, ST increased by 16%, from - 2.8 ± 0.83 days °C-1 during 1980-1994 to - 3.30 ± 0.65 days °C-1 during 2000-2014. For species with later LUD and longer OP, ST tended to increase more, while species with earlier LUD and shorter OP tended to display a decreasing ST. The standard deviation of preseason temperature impacted the temporal variation in ST. Chilling conditions influenced ST for some species, but photoperiod limitation did not have significant or coherent effects on changes in ST.

  3. Temperature sensitivity of microbial respiration of fine root litter in a temperate broad-leaved forest. (United States)

    Makita, Naoki; Kawamura, Ayumi


    The microbial decomposition respiration of plant litter generates a major CO2 efflux from terrestrial ecosystems that plays a critical role in the regulation of carbon cycling on regional and global scales. However, the respiration from root litter decomposition and its sensitivity to temperature changes are unclear in current models of carbon turnover in forest soils. Thus, we examined seasonal changes in the temperature sensitivity and decomposition rates of fine root litter of two diameter classes (0-0.5 and 0.5-2.0 mm) of Quercus serrata and Ilex pedunculosa in a deciduous broad-leaved forest. During the study period, fine root litter of both diameter classes and species decreased approximately exponentially over time. The Q10 values of microbial respiration rates of root litter for the two classes were 1.59-3.31 and 1.28-6.27 for Q. serrata and 1.36-6.31 and 1.65-5.86 for I. pedunculosa. A significant difference in Q10 was observed between the diameter classes, indicating that root diameter represents the initial substrate quality, which may determine the magnitude of Q10 value of microbial respiration. Changes in these Q10 values were related to seasonal soil temperature patterns; the values were higher in winter than in summer. Moreover, seasonal variations in Q10 were larger during the 2-year decomposition period than the 1-year period. These results showed that the Q10 values of fine root litter of 0-0.5 and 0.5-2.0 mm have been shown to increase with lower temperatures and with the higher recalcitrance pool of the decomposed substrate during 2 years of decomposition. Thus, the temperature sensitivity of microbial respiration in root litter showed distinct patterns according to the decay period and season because of the temperature acclimation and adaptation of the microbial decomposer communities in root litter.

  4. Immunolocalization and distribution of functional temperature-sensitive TRP channels in salivary glands. (United States)

    Sobhan, Ubaidus; Sato, Masaki; Shinomiya, Takashi; Okubo, Migiwa; Tsumura, Maki; Muramatsu, Takashi; Kawaguchi, Mitsuru; Tazaki, Masakazu; Shibukawa, Yoshiyuki


    Transient receptor potential (TRP) cation channels are unique cellular sensors involved in multiple cellular functions. Their role in salivary secretion remains to be elucidated. The expression and localization of temperature-sensitive TRP channels in salivary (submandibular, sublingual and parotid) glands were analyzed by immunohistochemistry and quantitative real-time reverse transcription plus the polymerase chain reaction (RT-PCR). The effects of various TRP channel agonists on carbachol (CCh)-induced salivary secretion in the submandibular gland and on the intracellular Ca(2+) concentration ([Ca(2+)]i) in a submandibular epithelial cell line were also investigated. Immunohistochemistry revealed the expression of TRP-melastatin subfamily member 8 (TRPM8) and TRP-ankyrin subfamily member 1 (TRPA1) in myoepithelial, acinar and ductal cells in the sublingual, submandibular and parotid glands. In addition, TRP-vanilloid subfamily member 1 (TRPV1), TRPV3 and TRPV4 were also expressed in myoepithelial, acinar and ductal cells in all three types of gland. Quantitative real-time RT-PCR results demonstrated the mRNA expression of TRPV1, TRPV3, TRPV4, TRPM8 and TRPA1 in acinar and ductal cells in these salivary glands. Perfusion of the entire submandibular gland with the TRPV1 agonist capsaicin (1 μM) via the submandibular artery significantly increased CCh-induced salivation, whereas perfusion with TRPM8 and TRPA1 agonists (0.5 μM WS12 and 100 μM allyl isothiocyanate) decreased it. Application of agonists for each of the thermosensitive TRP channels increased [Ca(2+)]i in a submandibular epithelial cell line. These results indicate that temperature-sensitive TRP channels are localized and distributed in acinar, ductal and myoepithelial cells in salivary glands and that they play a functional role in the regulation and/or modulation of salivary secretion.

  5. Regional variation in the temperature sensitivity of soil organic matter decomposition in China's forests and grasslands (United States)

    Liu, Yuan; He, Nianpeng


    How to assess the temperature sensitivity (Q10) of soil organic matter (SOM) decomposition and its regional variation with high accuracy is one of the largest uncertainties in determining the intensity and direction of the global carbon (C) cycle in response to climate change. In this study, we collected a series of soils from 22 forest sites and 30 grassland sites across China to explore regional variation in Q10 and its underlying mechanisms. We conducted a novel incubation experiment with periodically changing temperature (5-30 °C), while continuously measuring soil microbial respiration rates. The results showed that Q10 varied significantly across different ecosystems, ranging from 1.16 to 3.19 (mean 1.63). Q10 was ordered as follows: alpine grasslands (2.01) > temperate grasslands (1.81) > tropical forests (1.59) > temperate forests (1.55) > subtropical forests (1.52). The Q10 of grasslands (1.90) was significantly higher than that of forests (1.54). Furthermore, Q10 significantly increased with increasing altitude and decreased with increasing longitude. Environmental variables and substrate properties together explained 52% of total variation in Q10 across all sites. Overall, pH and soil electrical conductivity primarily explained spatial variation in Q10. The general negative relationships between Q10 and substrate quality among all ecosystem types supported the C quality temperature (CQT) hypothesis at a large scale, which indicated that soils with low quality should have higher temperature sensitivity. Furthermore, alpine grasslands, which had the highest Q10, were predicted to be more sensitive to climate change under the scenario of global warming.

  6. Study of the nonuniform behavior of temperature sensitivity in bare and embedded fiber Bragg gratings: experimental results and analysis. (United States)

    Mahakud, R; Kumar, J; Prakash, O; Dixit, S K


    This paper presents an experiment and analysis on the factors affecting nonlinear evolution of Bragg wavelength with change in temperature in typical bare and embedded fiber Bragg grating-based (FBG) temperature sensors. The purpose of the study was to find the constants in the function required to evaluate temperature from Bragg wavelength shift. The temperature sensitivity of bare FBGs was found to increase with temperature elevation, and is different for FBGs written in different fiber types. The average temperature sensitivity increased by about 20% when the bare FBG temperature was elevated from 25°C to 525°C. The average temperature sensitivity of the embedded FBG sensor, investigated in the temperature range of 30°C-90°C, was a factor of 2-3 times larger than for bare FBG, depending on its fastened length with the substrate. Analytically, it is shown that the nonuniform behavior of temperature sensitivity in bare FBGs is the result of both the thermal expansion effect of the fiber and the temperature derivatives of the effective refractive index. The strain transfer and temperature coefficients of thermal expansion of the substrate affect the nonuniform behavior of temperature sensitivity in embedded FBG sensors.

  7. Temperature Sensitivity of Microbial Respiration of Fine Root Litter in a Temperate Broad-Leaved Forest (United States)

    Makita, Naoki; Kawamura, Ayumi


    The microbial decomposition respiration of plant litter generates a major CO2 efflux from terrestrial ecosystems that plays a critical role in the regulation of carbon cycling on regional and global scales. However, the respiration from root litter decomposition and its sensitivity to temperature changes are unclear in current models of carbon turnover in forest soils. Thus, we examined seasonal changes in the temperature sensitivity and decomposition rates of fine root litter of two diameter classes (0–0.5 and 0.5–2.0 mm) of Quercus serrata and Ilex pedunculosa in a deciduous broad-leaved forest. During the study period, fine root litter of both diameter classes and species decreased approximately exponentially over time. The Q10 values of microbial respiration rates of root litter for the two classes were 1.59–3.31 and 1.28–6.27 for Q. serrata and 1.36–6.31 and 1.65–5.86 for I. pedunculosa. A significant difference in Q10 was observed between the diameter classes, indicating that root diameter represents the initial substrate quality, which may determine the magnitude of Q10 value of microbial respiration. Changes in these Q10 values were related to seasonal soil temperature patterns; the values were higher in winter than in summer. Moreover, seasonal variations in Q10 were larger during the 2-year decomposition period than the 1-year period. These results showed that the Q10 values of fine root litter of 0–0.5 and 0.5–2.0 mm have been shown to increase with lower temperatures and with the higher recalcitrance pool of the decomposed substrate during 2 years of decomposition. Thus, the temperature sensitivity of microbial respiration in root litter showed distinct patterns according to the decay period and season because of the temperature acclimation and adaptation of the microbial decomposer communities in root litter. PMID:25658106

  8. Linking temperature sensitivity of soil organic matter decomposition to its molecular structure, accessibility, and microbial physiology. (United States)

    Wagai, Rota; Kishimoto-Mo, Ayaka W; Yonemura, Seiichiro; Shirato, Yasuhito; Hiradate, Syuntaro; Yagasaki, Yasumi


    Temperature sensitivity of soil organic matter (SOM) decomposition may have a significant impact on global warming. Enzyme-kinetic hypothesis suggests that decomposition of low-quality substrate (recalcitrant molecular structure) requires higher activation energy and thus has greater temperature sensitivity than that of high-quality, labile substrate. Supporting evidence, however, relies largely on indirect indices of substrate quality. Furthermore, the enzyme-substrate reactions that drive decomposition may be regulated by microbial physiology and/or constrained by protective effects of soil mineral matrix. We thus tested the kinetic hypothesis by directly assessing the carbon molecular structure of low-density fraction (LF) which represents readily accessible, mineral-free SOM pool. Using five mineral soil samples of contrasting SOM concentrations, we conducted 30-days incubations (15, 25, and 35 °C) to measure microbial respiration and quantified easily soluble C as well as microbial biomass C pools before and after the incubations. Carbon structure of LFs (soil was measured by solid-state (13) C-NMR. Decomposition Q10 was significantly correlated with the abundance of aromatic plus alkyl-C relative to O-alkyl-C groups in LFs but not in bulk soil fraction or with the indirect C quality indices based on microbial respiration or biomass. The warming did not significantly change the concentration of biomass C or the three types of soluble C despite two- to three-fold increase in respiration. Thus, enhanced microbial maintenance respiration (reduced C-use efficiency) especially in the soils rich in recalcitrant LF might lead to the apparent equilibrium between SOM solubilization and microbial C uptake. Our results showed physical fractionation coupled with direct assessment of molecular structure as an effective approach and supported the enzyme-kinetic interpretation of widely observed C quality-temperature relationship for short-term decomposition. Factors

  9. A method to account for the temperature sensitivity of TCCON total column measurements (United States)

    Niebling, Sabrina G.; Wunch, Debra; Toon, Geoffrey C.; Wennberg, Paul O.; Feist, Dietrich G.


    The Total Carbon Column Observing Network (TCCON) consists of ground-based Fourier Transform Spectrometer (FTS) systems all around the world. It achieves better than 0.25% precision and accuracy for total column measurements of CO2 [Wunch et al. (2011)]. In recent years, the TCCON data processing and retrieval software (GGG) has been improved to achieve better and better results (e. g. ghost correction, improved a priori profiles, more accurate spectroscopy). However, a small error is also introduced by the insufficent knowledge of the true temperature profile in the atmosphere above the individual instruments. This knowledge is crucial to retrieve highly precise gas concentrations. In the current version of the retrieval software, we use six-hourly NCEP reanalysis data to produce one temperature profile at local noon for each measurement day. For sites in the mid latitudes which can have a large diurnal variation of the temperature in the lowermost kilometers of the atmosphere, this approach can lead to small errors in the final gas concentration of the total column. Here, we present and describe a method to account for the temperature sensitivity of the total column measurements. We exploit the fact that H2O is most abundant in the lowermost kilometers of the atmosphere where the largest diurnal temperature variations occur. We use single H2O absorption lines with different temperature sensitivities to gain information about the temperature variations over the course of the day. This information is used to apply a posteriori correction of the retrieved gas concentration of total column. In addition, we show that the a posteriori temperature correction is effective by applying it to data from Lamont, Oklahoma, USA (36,6°N and 97,5°W). We chose this site because regular radiosonde launches with a time resolution of six hours provide detailed information of the real temperature in the atmosphere and allow us to test the effectiveness of our correction. References

  10. Temperature sensitivity analysis of polarity controlled electrostatically doped tunnel field-effect transistor (United States)

    Nigam, Kaushal; Pandey, Sunil; Kondekar, P. N.; Sharma, Dheeraj


    The conventional tunnel field-effect transistors (TFETs) have shown potential to scale down in sub-22 nm regime due to its lower sub-threshold slope and robustness against short-channel effects (SCEs), however, sensitivity towards temperature variation is a major concern. Therefore, for the first time, we investigate temperature sensitivity analysis of a polarity controlled electrostatically doped tunnel field-effect transistor (ED-TFET). Different performance metrics and analog/RF figure-of-merits were considered and compared for both devices, and simulations were performed using Silvaco ATLAS device tool. We found that the variation in ON-state current in ED-TFET is almost temperature independent due to electrostatically doped mechanism, while, it increases in conventional TFET at higher temperature. Above room temperature, the variation in ION, IOFF, and SS sensitivity in ED-TFET are only 0.11%/K, 2.21%/K, and 0.63%/K, while, in conventional TFET the variations are 0.43%/K, 2.99%/K, and 0.71%/K, respectively. However, below room temperature, the variation in ED-TFET ION is 0.195%/K compared to 0.27%/K of conventional TFET. Moreover, it is analysed that the incomplete ionization effect in conventional TFET severely affects the drive current and the threshold voltage, while, ED-TFET remains unaffected. Hence, the proposed ED-TFET is less sensitive towards temperature variation and can be used for cryogenics as well as for high temperature applications.

  11. Targeting behavior of hepatic artery injected temperature sensitive liposomal adriamycin on tumor-bearing rats. (United States)

    Zou, Y Y; Ueno, M; Yamagishi, M; Horikoshi, I; Yamashita, I; Tazawa, K; Gu, X Q


    Temperature sensitive liposomal Adriamycin (LADM) was injected into the hepatic artery of rats bearing implanted hepatic tumors. Two hours after the injection, the liver was heated at 42 degrees C and maintained for six minutes at that temperature using local hyperthermia. Blood samples were taken at regular intervals until 8 hours after injection, at which time the animals were sacrificed and the drug distribution in the tissues was examined. Results indicate that the Adriamycin was released from the liposome, with the drug concentration in circulation peaking at 30 minutes after heating. High drug levels (25.2 micrograms/g of wet tissue) in the tumor and high tumor/liver Adriamycin level ratios (TLAR; 4.1) were found. The drug levels and the TLAR of the liposomal Adriamycin injection combined with heating (LADM H) were significantly different from those of the same dose of aqueous Adriamycin with heating (ADM H) or aqueous Adriamycin (ADM) and LADM without heating. The experiment shows that the LADM is cleared from the liver slowly, and when hyperthermia treatment at phase-transition temperature of the liposome is performed, the drug level in an implanted hepatic tumor is increased, and in the parenchyma is decreased. The results imply that targeting the hepatic tumor in this way may be an effective therapeutic method, and the drug release from the liposome may be controlled externally. This method appears promising for clinical practice.

  12. The validity of temperature-sensitive ingestible capsules for measuring core body temperature in laboratory protocols. (United States)

    Darwent, David; Zhou, Xuan; van den Heuvel, Cameron; Sargent, Charli; Roach, Greg D


    The human core body temperature (CBT) rhythm is tightly coupled to an endogenous circadian pacemaker located in the suprachiasmatic nucleus of the anterior hypothalamus. The standard method for assessing the status of this pacemaker is by continuous sampling of CBT using rectal thermometry. This research sought to validate the use of ingestible, temperature-sensitive capsules to measure CBT as an alternative to rectal thermometry. Participants were 11 young adult males who had volunteered to complete a laboratory protocol that extended across 12 consecutive days. A total of 87 functional capsules were ingested and eliminated by participants during the laboratory internment. Core body temperature samples were collected in 1-min epochs and compared to paired samples collected concurrently via rectal thermistors. Agreement between samples that were collected using ingestible sensors and rectal thermistors was assessed using the gold-standard limits of agreement method. Across all valid paired samples collected during the study (n = 120,126), the mean difference was 0.06°C, whereas the 95% CI (confidence interval) for differences was less than ±0.35°C. Despite the overall acceptable limits of agreement, systematic measurement bias was noted across the initial 5 h of sensor-transit periods and attributed to temperature gradations across the alimentary canal.

  13. Vanadium sesquioxide (V2O3)-based semiconducting temperature sensitive resistors for uncooled microbolometers (United States)

    Abdel-Rahman, Mohamed; Alduraibi, Mohammad; Zia, Muhammad Fakhar; Bahidra, Esme; Alasaad, Amr


    This paper reports on a semiconducting resistor material based on vanadium sesquioxide (V2O3) with electrical resistivity and temperature coefficient of resistance (TCR) appropriate for microbolometer applications. In this work, V2O3-based semiconducting resistor material was synthesized and electrically characterized. The developed material was prepared by annealing, in O2 and N2 atmospheres, a cascaded multilayer structure composed of V2O3 (10 nm) and V (5 nm) room temperature sputter coated thin films. The developed 55 nm thin film microbolometer resistor material possessed high temperature sensitivity from 20∘C to 45∘C with a TCR of -3.68%/∘C and room temperature resistivity of 0.57 Ω ṡcm for O2 annealed samples and a TCR of -3.72%/∘C and room temperature resistivity of 0.72 Ω ṡcm for N2 annealed samples. The surface morphologies of the synthesized thin films were studied using atomic force microscopy showing no significant post-growth annealing effect on the smoothness of the samples surfaces.

  14. Differential chromosomal and mitochondrial DNA synthesis in temperature-sensitive mutants of Ustilago maydis

    Energy Technology Data Exchange (ETDEWEB)

    Unrau, P.


    The amount and type of residual DNA synthesis was determined in eight temperature-sensitive mutants of the smut fungus Ustilago maydis after incubation at the restrictive temperature (32/sup 0/C) for eight hours. Mutants ts-220, ts-207, ts-432 and ts-346 were found to have an overall reduction in the synthesis of both nuclear and mitochondrial DNA in comparison to the wild-type. In mutants ts-20, tsd 1-1, ts-84 and pol 1-1 nuclear DNA synthesis was depressed relative to mitochondrial synthesis. The DNA-polymerase mutant pol 1-1 had persistent nuclear synthesis at about 50% of the rate of synthesis of mitochondrial DNA and similar behavior was observed in a diploid homozygous strain. Mutant ts-84 had an initial burst of DNA synthesis which was reduced for nuclear but not mitochondrial synthesis after three hours preincubation at 32/sup 0/C. tsd 1-1 and ts-20 had nuclear residual synthesis amounting to about 25% of the relative rate of mitochondrial synthesis which correlates to increasing UV sensitivity of these strains on incubation at 32/sup 0/C. A pol 1-1 ts-84 double mutant had an additive loss of nuclear DNA synthesis which indicates that the steps of replication involved may be sequential.

  15. Herceptin-conjugated temperature-sensitive immunoliposomes encapsulating gemcitabine for breast cancer. (United States)

    Shin, Dae Hwan; Koo, Min-Ji; Kim, Jung Seok; Kim, Jin-Seok


    Gemcitabine (2',2'-difluorodeoxycytidine, GCT) is an analog of deoxycytidine with cytotoxicity for breast cancer cells. However, because of its hepatotoxicity and other side effects, an efficient drug delivery system is needed for better therapeutic outcomes. A temperature-sensitive PEGylated immunoliposome (TSL) with trastuzumab (or Herceptin) attached encapsulating GCT (Her-PEG-TSL-GCT) was prepared. The mean diameter of the liposome was about 200 nm and the prepared immunoliposome showed the capacity to deliver the payload to the hyperthermic environment. The actual number of antibody molecules attached to one single liposome is about 19, with the GCT encapsulation efficiency of 54.6 ± 3.50 %. This immunoliposome shows a temperature-dependent drug release at around 41-43 °C. Anticancer activity of Her-PEG-TSL-GCT was determined using HER-2 expressing breast cancer cells, SK-BR-3, in vitro and resulted in increased cytotoxicity compared to free GCT (IC20 11.7 nM) or conventional liposome lacking the targeting antibody. In conclusion, these data show that improved delivery of GCT to breast cancer cells can be achieved by Her-PEG-TSL-GCT in vitro, and this strategy could be used for breast cancer therapy with further studies.

  16. Temperature sensitivity of surface tension-driven flows: Application to time-temperature integration (United States)

    Thomas, John; Hunter, Lawrence; Boyle, Michael


    The effects of time-dependent temperature fluctuations on surface-tension driven fluid flow inside a capillary are modeled using classical hydrodynamics. To begin, we use Newton's second law to derive a non-dimensional equation of motion that describes capillary flow as a function of system geometry, fluid properties, and fluid temperature. We use this model to examine how temperature excursions affect the instantaneous and long-term position and velocity of the fluid front inside the capillary. Next, we examine the combined effects of orientation change and temperature change on fluid movement through the capillary. Using this data, we show how to design a non-powered time-temperature integration device for recording the cumulative temperature exposure history of an asset or local environment. By selecting an appropriate fluid and capillary geometry, we show how such devices can be designed to exhibit arbitrary temperature sensitivities, operate over arbitrary monitoring periods (months to decades), and operate in a manner that does not depend on orientation.

  17. Control of bacteriophage-induced enzyme synthesis in cells infected with a temperature-sensitive mutant. (United States)

    Mathews, C K; Kessin, R H


    The timing of "early" and "late" protein synthesis in Escherichia coli infected with T-even bacteriophage was studied with a temperature-sensitive phage mutant, T4 tsL13. This strain was completely unable to direct the synthesis of phage deoxyribonucleic acid (DNA) at 44 C because it makes a deoxycytidylate hydroxymethylase which cannot act at that temperature. However, the mutant did multiply normally at 30 C. No detectable formation of the late protein, lysozyme, occurred at 44 C, in agreement with the idea, proposed by several workers, that DNA replication is necessary for activation of late genetic functions. However, the formation of an early enzyme, thymidylate synthetase, was shut off at about 10 min, as in normal infection. This implied that separate mechanisms were responsible for cessation of early functions and activation of late ones. That the infected cell at 44 C retained the capacity for synthesis of early enzymes was shown by the fact that DNA synthesis occurred after a culture was transferred from 44 to 30 C as late as 30 min after infection. This synthesis was inhibited by chloramphenicol, indicating that de novo synthesis of an early enzyme can take place at a late period in development. It is suggested that cells infected under normal conditions maintained an appreciable rate of early enzyme synthesis throughout the course of infection.

  18. Differences in SOM decomposition and temperature sensitivity among soil aggregate size classes in a temperate grasslands.

    Directory of Open Access Journals (Sweden)

    Qing Wang

    Full Text Available The principle of enzyme kinetics suggests that the temperature sensitivity (Q10 of soil organic matter (SOM decomposition is inversely related to organic carbon (C quality, i.e., the C quality-temperature (CQT hypothesis. We tested this hypothesis by performing laboratory incubation experiments with bulk soil, macroaggregates (MA, 250-2000 μm, microaggregates (MI, 53-250 μm, and mineral fractions (MF, MF>bulk soil >MI(P <0.05. The Q10 values were highest for MA, followed (in decreasing order by bulk soil, MF, and MI. Similarly, the activation energies (Ea for MA, bulk soil, MF, and MI were 48.47, 33.26, 27.01, and 23.18 KJ mol-1, respectively. The observed significant negative correlations between Q10 and C quality index in bulk soil and soil aggregates (P<0.05 suggested that the CQT hypothesis is applicable to soil aggregates. Cumulative C emission differed significantly among aggregate size classes (P <0.0001, with the largest values occurring in MA (1101 μg g-1, followed by MF (976 μg g-1 and MI (879 μg g-1. These findings suggest that feedback from SOM decomposition in response to changing temperature is closely associated withsoil aggregation and highlights the complex responses of ecosystem C budgets to future warming scenarios.

  19. Engineering Rubisco activase from thermophilic cyanobacteria into high-temperature sensitive plants. (United States)

    Ogbaga, Chukwuma C; Stepien, Piotr; Athar, Habib-Ur-Rehman; Ashraf, Muhammad


    In the past decade, various strategies to improve photosynthesis and crop yield, such as leaf morphology, light interception and use efficiency, biochemistry of light reactions, stomatal conductance, carboxylation efficiency, and source to sink regulation, have been discussed at length. Leaf morphology and physiology are tightly coupled to light capturing efficiency, gas exchange capacity, and temperature regulation. However, apart from the photoprotective mechanism of photosystem-II (PSII), i.e. non-photochemical quenching, very low genetic variation in the components of light reactions has been observed in plants. In the last decade, biochemistry-based enhancement of carboxylation efficiency that improves photosynthesis in plants was one of the potential strategies for improving plant biomass production. Enhancement of activation of the ubiquitous enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC by Rubisco activase may be another potential strategy for improving a photosynthesis-driven increase in crop yield. Rubisco activase modifies the conformation of the active center in Rubisco by removing tightly bound inhibitors, thereby contributing to enzyme activation and rapid carboxylation. Thermophilic cyanobacteria are oxygenic photosynthetic bacteria that thrive in high-temperature environments. This critical review discusses the prospects for and the potential of engineering Rubisco activase from thermophilic cyanobacteria into temperature-sensitive plants, to increase the threshold temperature and survival of these plants in arid regions.

  20. Temperature sensitivity of resistance to two pathotypes of Plasmodiophora brassicae in Brassica oleracea

    Directory of Open Access Journals (Sweden)

    R. L. Gabrielson


    Full Text Available Several methods were evaluated in an attempt to develop a greenhouse screening procedure that would predict field resistance of brassica breeding lines to clubroot disease caused by Plasmodiophora brassicae. Several Brassica oleracea cultivars and breeding lines bred for resistance to Plasmodiophora brassicae and a susceptible Chinese cabbage cultivar were exposed to high levels of inoculum of both pathotypes PB 6, PB 7 at 12, 15, 20, 25 and 30°C. No infection occurred on any host at 12°C. Chinese cabbage was heavily diseased from 15-30°C. Bagder Shipper cabbage, a cauliflower deriving resistance from this variety, and Oregon CR-1 broccoli were resistant to pathotype PB 6 at 15 and 20°C and partially resistant at 25 and 30°C. They were resistant to pathotype PB 7 and 15°C and almost totally susceptible at 20, 25° and 30°C. Oregon cabbage line OR 123 was resistant to pathotype PB 6 at 15°C at almost completely susceptible at 20, 25 and 30°C. It was resistant to pathotype PB 7 at all temperatures. Temperature sensitivity of resistance can partially explain why breeding lines are resistant in field trials and susceptible in greenhouse tests.

  1. In vivo non-invasive optical imaging of temperature-sensitive co-polymeric nanohydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Chen Haiyan; Hu Yuzhu [Department of Analytical Chemistry, School of Basic Science, 24 Shennong Road, China Pharmaceutical University, Nanjing 210009 (China); Zhang Jian; Liu Fei; Chen Xinyang; Gu Yueqing [Department of Biomedical Engineering, School of Life Science and Technology, 24 Shennong Road, China Pharmaceutical University, Nanjing 210009 (China); Qian Zhiyu [Department of Biomedical Engineering, School of Automation, Nanjing University of Aeronautics and Astronautics, Nanjing 21009 (China)], E-mail:, E-mail:


    Assessment of hyperthermia in pathological tissue is a promising strategy for earlier diagnosis of malignant tumors. In this study, temperature-sensitive co-polymeric nanohydrogel poly(N-isopropylacrylamide-co-acrylic acid) (PNIPA-co-AA) was successfully synthesized by the precipitation polymerization method. The diameters of nanohydrogels were controlled to be less than 100 nm. Also the lower critical solution temperature (LCST, 40 deg. C) was manipulated above physiological temperature after integration of near-infrared (NIR) organic dye (heptamethine cyanine dye, HMCD) within its interior cores. NIR laser light (765 nm), together with sensitive charge coupled device (CCD) cameras, were designed to construct an NIR imaging system. The dynamic behaviors of PNIPA-co-AA-HMCD composites in denuded mice with or without local hyperthermia treatment were real-time monitored by an NIR imager. The results showed that the PNIPA-co-AA-HMCD composites accumulated in the leg treated with local heating and diffused much slower than that in the other leg without heating. The results demonstrated that the temperature-responsive PNIPA-co-AA-HMCD composites combining with an NIR imaging system could be an effective temperature mapping technique, which provides a promising prospect for earlier tumor diagnosis and thermally related therapeutic assessment.

  2. Temperature-sensitive retinoid isomerase activity of RPE65 mutants associated with Leber Congenital Amaurosis. (United States)

    Li, Songhua; Hu, Jane; Jin, Robin J; Aiyar, Ashok; Jacobson, Samuel G; Bok, Dean; Jin, Minghao


    RPE65 is a membrane-associated retinoid isomerase involved in the visual cycle responsible for sustaining vision. Many mutations in the human RPE65 gene are associated with distinct forms of retinal degenerative diseases. The pathogenic mechanisms for most of these mutations remain poorly understood. Here, we show that three Leber congenital amaurosis -associated RPE65 mutants (R91W, Y249C and R515W) undergo rapid proteasomal degradation mediated by the 26 S proteasome non-ATPase regulatory subunit 13 (PSMD13) in cultured human retinal pigment epithelium (RPE) cells. These mutant proteins formed cytosolic inclusion bodies or high molecular weight complexes via disulfide bonds. The mutations are mapped on non-active sites but severely reduced isomerase activity of RPE65. At 30°C, however, the enzymatic function and membrane-association of the mutant RPE65s are significantly rescued possibly due to proper folding. In addition, PSMD13 displayed a drastically decreased effect on degradation of the mutant proteins in the cells grown at 30°C. These results suggest that PSMD13 plays a critical role in regulating pathogenicity of the mutations and the molecular basis for the PSMD13-mediated rapid degradation and loss of function of the mutants is misfolding of RPE65. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  3. Temperature sensitivity of organic substrate decay varies with pH (United States)

    Min, K.; Lehmeier, C.; Ballantyne, F.; Billings, S. A.


    Cellulose is the most abundant biopolymer in soils and globally ubiquitous. It serves as a primary carbon source for myriad microbes able to release cellulases which cleave the cellulose into smaller molecules. For example, β-glucosidase, one type of cellulase, breaks down a terminal β-glycosidic bond of cellulose. The carbon of the liberated glucose becomes available for microbial uptake, after which it can then be mineralized and returned to the atmosphere via heterotrophic respiration. Thus, exoenzymes play an important role in the global cycling of carbon. Numerous studies suggest that global warming potentially increases the rate at which β-glucosidase breaks down cellulose, but it is not known how pH of the soil solution influences the effect of temperature on cellulose decomposition rates; this is important given the globally wide range of soil pH. Using fluorescence enzyme assay techniques, we studied the effect of temperature and pH on the reaction rate at which purified β-Glucosidase decays β-D-cellobioside (a compound often employed to simulate cellulose). We evaluated the temperature sensitivity of this reaction at five temperatures (5, 10, 15, 20, and 25°C) and six pH values (3.5, 4.5, 5.5, 6.5, 7.5, and 8.5)encompassing the naturally occurring range in soils, in a full-factorial design. First, we determined Vmax at 25°C and pH 6.5, standard conditions for measuring enzyme activities in many studies. The Vmax was 858.65 μmol h-1mg-1and was achieved at substrate concentration of 270 μM. At all pH values, the reaction rate slowed down at lower temperatures; at a pH of 3.5, no enzymatic activity was detected. The enzyme activity was significantly different between pH 4.5 and higher pHs. For example, enzyme reactivity at pH 4.5 was significantly lower than that at 7.5 at 20 and 25°C (Bonferroni-corrected P =0.0006, 0.0004, respectively), but not at lower temperatures. Similarly, enzyme reactivity at pH 4.5 was lower than that at pH 8.5 at 10, 15

  4. Preparation of a Paeonol-Containing Temperature-Sensitive In Situ Gel and Its Preliminary Efficacy on Allergic Rhinitis

    Directory of Open Access Journals (Sweden)

    Jian Zheng


    Full Text Available In this paper, the optimal composition of a paeonol temperature-sensitive in situ gel composed of poloxamer 407 (P407 was determined, and a preliminary study of its effect on allergic rhinitis was performed. The optimal composition of the paeonol temperature-sensitive in situ gel included 2% paeonol inclusion, 22% P407, 2% poloxamer 188 (P188 and 2% PEG6000, as assessed by thermodynamic and rheological studies. The toad palate model was employed to study the toxicity of the paeonol temperature-sensitive in situ gel on the nasal mucosa. The result of this experiment showed low toxicity to cilia, which allows the gel to be used for nasal administration. The Franz diffusion cell method was used to study the in vitro release of paeonol and suggested that the in vitro release was in line with the Higuchi equation. This result suggests that the paeonol could be absorbed into the body through mucous membranes and had some characteristics of a sustained effect. Finally, the guinea pig model of ovalbumin sensitized allergic rhinitis was used to evaluate the preliminary efficacy of the gel, with the paeonol temperature-sensitive in situ gel showing a significant effect on the guinea pig model of sensitized allergic rhinitis (AR.

  5. Effects of soil moisture on the temperature sensitivity of soil heterotrophic respiration: a laboratory incubation study.

    Directory of Open Access Journals (Sweden)

    Weiping Zhou

    Full Text Available The temperature sensitivity (Q10 of soil heterotrophic respiration (Rh is an important ecological model parameter and may vary with temperature and moisture. While Q10 generally decreases with increasing temperature, the moisture effects on Q10 have been controversial. To address this, we conducted a 90-day laboratory incubation experiment using a subtropical forest soil with a full factorial combination of five moisture levels (20%, 40%, 60%, 80%, and 100% water holding capacity--WHC and five temperature levels (10, 17, 24, 31, and 38°C. Under each moisture treatment, Rh was measured several times for each temperature treatment to derive Q10 based on the exponential relationships between Rh and temperature. Microbial biomass carbon (MBC, microbial community structure and soil nutrients were also measured several times to detect their potential contributions to the moisture-induced Q10 variation. We found that Q10 was significantly lower at lower moisture levels (60%, 40% and 20% WHC than at higher moisture level (80% WHC during the early stage of the incubation, but became significantly higher at 20%WHC than at 60% WHC and not significantly different from the other three moisture levels during the late stage of incubation. In contrast, soil Rh had the highest value at 60% WHC and the lowest at 20% WHC throughout the whole incubation period. Variations of Q10 were significantly associated with MBC during the early stages of incubation, but with the fungi-to-bacteria ratio during the later stages, suggesting that changes in microbial biomass and community structure are related to the moisture-induced Q10 changes. This study implies that global warming's impacts on soil CO2 emission may depend upon soil moisture conditions. With the same temperature rise, wetter soils may emit more CO2 into the atmosphere via heterotrophic respiration.

  6. Temperature-sensitive PSII: a novel approach for sustained photosynthetic hydrogen production. (United States)

    Bayro-Kaiser, Vinzenz; Nelson, Nathan


    The need for energy and the associated burden are ever growing. It is crucial to develop new technologies for generating clean and efficient energy for society to avoid upcoming energetic and environmental crises. Sunlight is the most abundant source of energy on the planet. Consequently, it has captured our interest. Certain microalgae possess the ability to capture solar energy and transfer it to the energy carrier, H2. H2 is a valuable fuel, because its combustion produces only one by-product: water. However, the establishment of an efficient biophotolytic H2 production system is hindered by three main obstacles: (1) the hydrogen-evolving enzyme, [FeFe]-hydrogenase, is highly sensitive to oxygen; (2) energy conversion efficiencies are not economically viable; and (3) hydrogen-producing organisms are sensitive to stressful conditions in large-scale production systems. This study aimed to circumvent the oxygen sensitivity of this process with a cyclic hydrogen production system. This approach required a mutant that responded to high temperatures by reducing oxygen evolution. To that end, we randomly mutagenized the green microalgae, Chlamydomonas reinhardtii, to generate mutants that exhibited temperature-sensitive photoautotrophic growth. The selected mutants were further characterized by their ability to evolve oxygen and hydrogen at 25 and 37 °C. We identified four candidate mutants for this project. We characterized these mutants with PSII fluorescence, P700 absorbance, and immunoblotting analyses. Finally, we demonstrated that these mutants could function in a prototype hydrogen-producing bioreactor. These mutant microalgae represent a novel approach for sustained hydrogen production.

  7. Increase of ozone concentrations, its temperature sensitivity and the precursor factor in South China

    Directory of Open Access Journals (Sweden)

    Y. C. Lee


    Full Text Available Concerns have been raised about the possible connections between the local and regional photochemical problem and global warming. The current study assesses the trend of ozone in Hong Kong and the Pearl River Delta (PRD in South China and investigates the interannual changes of sensitivity of ozone to air temperature, as well as the trends in regional precursors. Results reveal, at the three monitoring sites from the mid-1990s to 2010, an increase in the mean ozone concentrations from 1.0 to 1.6 µg m−3 per year. The increase occurred in all seasons, with the highest rate in autumn. This is consistent with trends and temperature anomalies in the region. The increase in the sensitivity of ozone to temperature is clearly evident from the correlation between ozone (OMI [Ozone Monitoring Instrument] column amount and surface air temperature (from the Atmospheric Infrared Sounder displayed in the correlation maps for the PRD during the prominently high ozone period of July–September. It is observed to have increased from 2005 to 2010, the latter being the hottest year on record globally. To verify this temporal change in sensitivity, the ground-level trends of correlation coefficients/regression slopes are analysed. As expected, results reveal a statistically significant upward trend over a 14-year period (1997–2010. While the correlation revealed in the correlation maps is in agreement with the corresponding OMI ozone maps when juxtaposed, temperature sensitivity of surface ozone also shows an association with ozone concentration, with R=0.5. These characteristics of ozone sensitivity are believed to have adverse implications for the region. As shown by ground measurements and/or satellite analyses, the decrease in nitrogen oxides (NO2 and NOx in Hong Kong is not statistically significant while NO2 of the PRD has only very slightly changed. However, carbon dioxide has remarkably declined in the whole region. While these observations concerning

  8. Comparison of conventional chemotherapy, stealth liposomes and temperature-sensitive liposomes in a mathematical model. (United States)

    Gasselhuber, Astrid; Dreher, Matthew R; Rattay, Frank; Wood, Bradford J; Haemmerich, Dieter


    Various liposomal drug carriers have been developed to overcome short plasma half-life and toxicity related side effects of chemotherapeutic agents. We developed a mathematical model to compare different liposome formulations of doxorubicin (DOX): conventional chemotherapy (Free-DOX), Stealth liposomes (Stealth-DOX), temperature sensitive liposomes (TSL) with intra-vascular triggered release (TSL-i), and TSL with extra-vascular triggered release (TSL-e). All formulations were administered as bolus at a dose of 9 mg/kg. For TSL, we assumed locally triggered release due to hyperthermia for 30 min. Drug concentrations were determined in systemic plasma, aggregate body tissue, cardiac tissue, tumor plasma, tumor interstitial space, and tumor cells. All compartments were assumed perfectly mixed, and represented by ordinary differential equations. Contribution of liposomal extravasation was negligible in the case of TSL-i, but was the major delivery mechanism for Stealth-DOX and for TSL-e. The dominant delivery mechanism for TSL-i was release within the tumor plasma compartment with subsequent tissue- and cell uptake of released DOX. Maximum intracellular tumor drug concentrations for Free-DOX, Stealth-DOX, TSL-i, and TSL-e were 3.4, 0.4, 100.6, and 15.9 µg/g, respectively. TSL-i and TSL-e allowed for high local tumor drug concentrations with reduced systemic exposure compared to Free-DOX. While Stealth-DOX resulted in high tumor tissue concentrations compared to Free-DOX, only a small fraction was bioavailable, resulting in little cellular uptake. Consistent with clinical data, Stealth-DOX resulted in similar tumor intracellular concentrations as Free-DOX, but with reduced systemic exposure. Optimal release time constants for maximum cellular uptake for Stealth-DOX, TSL-e, and TSL-i were 45 min, 11 min, and constants were shorter for MDR cells, with ∼4 min for Stealth-DOX and for TSL-e. Tissue concentrations correlated well quantitatively with a prior in-vivo study

  9. Rate of warming affects temperature sensitivity of anaerobic peat decomposition and greenhouse gas production. (United States)

    Sihi, Debjani; Inglett, Patrick W; Gerber, Stefan; Inglett, Kanika S


    Temperature sensitivity of anaerobic carbon mineralization in wetlands remains poorly represented in most climate models and is especially unconstrained for warmer subtropical and tropical systems which account for a large proportion of global methane emissions. Several studies of experimental warming have documented thermal acclimation of soil respiration involving adjustments in microbial physiology or carbon use efficiency (CUE), with an initial decline in CUE with warming followed by a partial recovery in CUE at a later stage. The variable CUE implies that the rate of warming may impact microbial acclimation and the rate of carbon-dioxide (CO2 ) and methane (CH4 ) production. Here, we assessed the effects of warming rate on the decomposition of subtropical peats, by applying either a large single-step (10°C within a day) or a slow ramping (0.1°C/day for 100 days) temperature increase. The extent of thermal acclimation was tested by monitoring CO2 and CH4 production, CUE, and microbial biomass. Total gaseous C loss, CUE, and MBC were greater in the slow (ramp) warming treatment. However, greater values of CH4 -C:CO2 -C ratios lead to a greater global warming potential in the fast (step) warming treatment. The effect of gradual warming on decomposition was more pronounced in recalcitrant and nutrient-limited soils. Stable carbon isotopes of CH4 and CO2 further indicated the possibility of different carbon processing pathways under the contrasting warming rates. Different responses in fast vs. slow warming treatment combined with different endpoints may indicate alternate pathways with long-term consequences. Incorporations of experimental results into organic matter decomposition models suggest that parameter uncertainties in CUE and CH4 -C:CO2 -C ratios have a larger impact on long-term soil organic carbon and global warming potential than uncertainty in model structure, and shows that particular rates of warming are central to understand the response of

  10. Temperature-Sensitive Live-Attenuated Canine Influenza Virus H3N8 Vaccine. (United States)

    Nogales, Aitor; Rodriguez, Laura; Chauché, Caroline; Huang, Kai; Reilly, Emma C; Topham, David J; Murcia, Pablo R; Parrish, Colin R; Martínez-Sobrido, Luis


    Canine influenza is a respiratory disease of dogs caused by canine influenza virus (CIV). CIV subtypes responsible for influenza in dogs include H3N8, which originated from the transfer of H3N8 equine influenza virus to dogs; and the H3N2 CIV, which is an avian-origin virus that adapted to infect dogs. Influenza infections are most effectively prevented through vaccination to reduce transmission and future infection. Currently, only inactivated influenza vaccines (IIVs) are available for the prevention of CIV in dogs. However, the efficacy of IIVs is suboptimal, and novel approaches are necessary for the prevention of disease caused by this canine respiratory pathogen. Using reverse genetics techniques, we have developed a live-attenuated CIV vaccine (LACIV) for the prevention of H3N8 CIV. The H3N8 LACIV replicates efficiently in canine cells at 33°C but is impaired at temperatures of 37 to 39°C and was attenuated compared to wild-type H3N8 CIV in vivo and ex vivo The LACIV was able to induce protection against H3N8 CIV challenge with a single intranasal inoculation in mice. Immunogenicity and protection efficacy were better than that observed with a commercial CIV H3N8 IIV but provided limited cross-reactive immunity and heterologous protection against H3N2 CIV. These results demonstrate the feasibility of implementing a LAIV approach for the prevention and control of H3N8 CIV in dogs and suggest the need for a new LAIV for the control of H3N2 CIV. Two influenza A virus subtypes has been reported in dogs in the last 16 years: the canine influenza viruses (CIV) H3N8 and H3N2 of equine and avian origins, respectively. To date, only inactivated influenza vaccines (IIVs) are available to prevent CIV infections. Here, we report the generation of a recombinant, temperature-sensitive H3N8 CIV as a live-attenuated influenza vaccine (LAIV), which was attenuated in mice and dog tracheal, explants compared to CIV H3N8 wild type. A single dose of H3N8 LACIV showed

  11. Thermo-optical characterization of fluorescent rhodamine B based temperature-sensitive nanosensors using a CMOS MEMS micro-hotplate☆ (United States)

    Chauhan, Veeren M.; Hopper, Richard H.; Ali, Syed Z.; King, Emma M.; Udrea, Florin; Oxley, Chris H.; Aylott, Jonathan W.


    A custom designed microelectromechanical systems (MEMS) micro-hotplate, capable of operating at high temperatures (up to 700 °C), was used to thermo-optically characterize fluorescent temperature-sensitive nanosensors. The nanosensors, 550 nm in diameter, are composed of temperature-sensitive rhodamine B (RhB) fluorophore which was conjugated to an inert silica sol–gel matrix. Temperature-sensitive nanosensors were dispersed and dried across the surface of the MEMS micro-hotplate, which was mounted in the slide holder of a fluorescence confocal microscope. Through electrical control of the MEMS micro-hotplate, temperature induced changes in fluorescence intensity of the nanosensors was measured over a wide temperature range. The fluorescence response of all nanosensors dispersed across the surface of the MEMS device was found to decrease in an exponential manner by 94%, when the temperature was increased from 25 °C to 145 °C. The fluorescence response of all dispersed nanosensors across the whole surface of the MEMS device and individual nanosensors, using line profile analysis, were not statistically different (p nanosensors could find potential application in the measurement of temperature in biological and micro-electrical systems. PMID:25844025

  12. Thermo-optical characterization of fluorescent rhodamine B based temperature-sensitive nanosensors using a CMOS MEMS micro-hotplate. (United States)

    Chauhan, Veeren M; Hopper, Richard H; Ali, Syed Z; King, Emma M; Udrea, Florin; Oxley, Chris H; Aylott, Jonathan W


    A custom designed microelectromechanical systems (MEMS) micro-hotplate, capable of operating at high temperatures (up to 700 °C), was used to thermo-optically characterize fluorescent temperature-sensitive nanosensors. The nanosensors, 550 nm in diameter, are composed of temperature-sensitive rhodamine B (RhB) fluorophore which was conjugated to an inert silica sol-gel matrix. Temperature-sensitive nanosensors were dispersed and dried across the surface of the MEMS micro-hotplate, which was mounted in the slide holder of a fluorescence confocal microscope. Through electrical control of the MEMS micro-hotplate, temperature induced changes in fluorescence intensity of the nanosensors was measured over a wide temperature range. The fluorescence response of all nanosensors dispersed across the surface of the MEMS device was found to decrease in an exponential manner by 94%, when the temperature was increased from 25 °C to 145 °C. The fluorescence response of all dispersed nanosensors across the whole surface of the MEMS device and individual nanosensors, using line profile analysis, were not statistically different (p nanosensors could find potential application in the measurement of temperature in biological and micro-electrical systems.

  13. Imparting Temperature Sensitivity and Attenuation in Ferrets to A/Puerto Rico/8/34 Influenza Virus by Transferring the Genetic Signature for Temperature Sensitivity from Cold-Adapted A/Ann Arbor/6/60


    Jin, Hong; Zhou, Helen; Lu, Bin; Kemble, George


    The four temperature-sensitive (ts) loci identified in the PB1 and PB2 gene segments of cold-adapted A/Ann Arbor/6/60 influenza virus, the master donor virus for influenza A virus (MDV-A) FluMist vaccines, were introduced into a divergent A/Puerto Rico/8/34 influenza virus strain. Recombinant A/Puerto Rico/8/34 virus with these four introduced ts loci exhibited both ts and att phenotypes similar to those of MDV-A, which could be used as a donor virus for manufacturing large quantities of inac...

  14. A polynucleotide repeat expansion causing temperature-sensitivity persists in wild Irish accessions of Arabidopsis thaliana

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    Amanda Tabib


    Full Text Available Triplet repeat expansions underlie several human genetic diseases such as Huntington’s disease and Friedreich’s ataxia. Although such mutations are primarily known from humans, a triplet expansion associated genetic defect has also been reported at the IIL1 locus in the Bur-0 accession of the model plant Arabidopsis thaliana. The IIL1 triplet expansion is an example of cryptic genetic variation as its phenotypic effects are seen only under genetic or environmental perturbation, with high temperatures resulting in a growth defect. Here we demonstrate that the IIL1 triplet expansion associated growth defect is not a general stress response and is specific to particular environmental perturbations. We also confirm and map genetic modifiers that suppress the effect of IIL1 triplet repeat expansion. By collecting and analysing accessions from the island of Ireland, we recover the repeat expansion in wild populations suggesting that the repeat expansion has persisted at least 60 years in Ireland. Through genome-wide genotyping, we show that the repeat expansion is present in diverse Irish populations. Our findings indicate that even deleterious alleles can persist in populations if their effect is conditional. Our study demonstrates that analysis of groups of wild populations is a powerful tool for understanding the dynamics of cryptic genetic variation.

  15. Expression of temperature-sensitive ion channel TRPM8 in sperm cells correlates with vertebrate evolution

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    Rakesh Kumar Majhi


    Full Text Available Transient Receptor Potential cation channel, subfamily Melastatin, member 8 (TRPM8 is involved in detection of cold temperature, different noxious compounds and in execution of thermo- as well as chemo-sensitive responses at cellular levels. Here we explored the molecular evolution of TRPM8 by analyzing sequences from various species. We elucidate that several regions of TRPM8 had different levels of selection pressure but the 4th–5th transmembrane regions remain highly conserved. Analysis of synteny suggests that since vertebrate origin, TRPM8 gene is linked with SPP2, a bone morphogen. TRPM8, especially the N-terminal region of it, seems to be highly variable in human population. We found 16,656 TRPM8 variants in 1092 human genomes with top variations being SNPs, insertions and deletions. A total of 692 missense mutations are also mapped to human TRPM8 protein of which 509 seem to be delateroiours in nature as supported by Polyphen V2, SIFT and Grantham deviation score. Using a highly specific antibody, we demonstrate that TRPM8 is expressed endogenously in the testis of rat and sperm cells of different vertebrates ranging from fish to higher mammals. We hypothesize that TRPM8 had emerged during vertebrate evolution (ca 450 MYA. We propose that expression of TRPM8 in sperm cell and its role in regulating sperm function are important factors that have guided its molecular evolution, and that these understandings may have medical importance.

  16. Upconverting PAAm/PNIPAM/NaYF{sub 4}:Yb:Er hydrogel with enhanced luminescence temperature sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jiachang; He, Benzhao; Cheng, Zehong; Zhou, Li, E-mail:


    We present a one-step approach to combine the functional features of upconverting NaYF{sub 4}:Yb:Er nanoparticles and thermosensitive poly(N-isopropylacrylamide) (PNIPAM) for luminescence thermometry. Dual-functional hydrogel that simultaneously possesses strong upconversion luminescence (UL) and temperature responsibility was fabricated based on the crosslinking of poly(acrylamide) in the presence of PNIPAM and NaYF{sub 4}:Yb:Er nanoparticles. The obtained hydrogel exhibited reversibly temperature-dependent UL and highly enhanced sensibility. The luminescence temperature sensitivity reached 1.9% per °C and 0.7% per °C in the range of 27–33 °C and 35–45 °C, respectively. The maximum sensitivity could even reach 26.5% per °C in the range of 33–35 °C. Considering the facile fabrication process and fine luminescence thermometry performance, this study thus opens up new opportunities for preparing highly sensitive temperature sensors. - Highlights: • One-step fabrication of upconverting and thermosensitve PAAm/PNIPAM/NaYF{sub 4}:Yb:Er hydrogel is reported. • The combination of functional features of NaYF{sub 4}:Yb:Er upconversion nanoparticles (UCNPs) and thermosensitve PNIPAM can efficiently enhance the luminescence temperature sensitivity of UCNPs. • The luminescence temperature sensitivity of hydrogel can respectively reach 1.9% per °C and 0.7% per °C in the range of 27–33 °C and 35–45 °C. • The maximum sensitivity can even reach 26.5% per °C in range of 33–35 °C.

  17. A major QTL affects temperature sensitive adult lethality and inbreeding depression in life span in Drosophila melanogaster.

    DEFF Research Database (Denmark)

    Vermeulen, Corneel J.; Bijlsma, R.; Loeschcke, Volker


    of inbreeding effects in specific traits, such as age-specific mortality and life span, provide a good starting point, as a limited set of genes is expected to be involved. Results Here we report on a QTL mapping study on inbreeding related and temperature sensitive lethality in male Drosophila melanogaster...... simple, being due mainly to a single recessive QTL on the left arm of chromosome 2. This locus colocalised with a QTL that conditioned variation in female life span, acting as an overdominant locus for this trait. Male life span was additionally affected by variation at the X-chromosome. Conclusion...

  18. O-Fucose Monosaccharide of Drosophila Notch Has a Temperature-sensitive Function and Cooperates with O-Glucose Glycan in Notch Transport and Notch Signaling Activation* (United States)

    Ishio, Akira; Sasamura, Takeshi; Ayukawa, Tomonori; Kuroda, Junpei; Ishikawa, Hiroyuki O.; Aoyama, Naoki; Matsumoto, Kenjiroo; Gushiken, Takuma; Okajima, Tetsuya; Yamakawa, Tomoko; Matsuno, Kenji


    Notch (N) is a transmembrane receptor that mediates the cell-cell interactions necessary for many cell fate decisions. N has many epidermal growth factor-like repeats that are O-fucosylated by the protein O-fucosyltransferase 1 (O-Fut1), and the O-fut1 gene is essential for N signaling. However, the role of the monosaccharide O-fucose on N is unclear, because O-Fut1 also appears to have O-fucosyltransferase activity-independent functions, including as an N-specific chaperon. Such an enzymatic activity-independent function could account for the essential role of O-fut1 in N signaling. To evaluate the role of the monosaccharide O-fucose modification in N signaling, here we generated a knock-in mutant of O-fut1 (O-fut1R245A knock-in), which expresses a mutant protein that lacks O-fucosyltransferase activity but maintains the N-specific chaperon activity. Using O-fut1R245A knock-in and other gene mutations that abolish the O-fucosylation of N, we found that the monosaccharide O-fucose modification of N has a temperature-sensitive function that is essential for N signaling. The O-fucose monosaccharide and O-glucose glycan modification, catalyzed by Rumi, function redundantly in the activation of N signaling. We also showed that the redundant function of these two modifications is responsible for the presence of N at the cell surface. Our findings elucidate how different forms of glycosylation on a protein can influence the protein's functions. PMID:25378397

  19. O-fucose monosaccharide of Drosophila Notch has a temperature-sensitive function and cooperates with O-glucose glycan in Notch transport and Notch signaling activation. (United States)

    Ishio, Akira; Sasamura, Takeshi; Ayukawa, Tomonori; Kuroda, Junpei; Ishikawa, Hiroyuki O; Aoyama, Naoki; Matsumoto, Kenjiroo; Gushiken, Takuma; Okajima, Tetsuya; Yamakawa, Tomoko; Matsuno, Kenji


    Notch (N) is a transmembrane receptor that mediates the cell-cell interactions necessary for many cell fate decisions. N has many epidermal growth factor-like repeats that are O-fucosylated by the protein O-fucosyltransferase 1 (O-Fut1), and the O-fut1 gene is essential for N signaling. However, the role of the monosaccharide O-fucose on N is unclear, because O-Fut1 also appears to have O-fucosyltransferase activity-independent functions, including as an N-specific chaperon. Such an enzymatic activity-independent function could account for the essential role of O-fut1 in N signaling. To evaluate the role of the monosaccharide O-fucose modification in N signaling, here we generated a knock-in mutant of O-fut1 (O-fut1(R245A knock-in)), which expresses a mutant protein that lacks O-fucosyltransferase activity but maintains the N-specific chaperon activity. Using O-fut1(R245A knock-in) and other gene mutations that abolish the O-fucosylation of N, we found that the monosaccharide O-fucose modification of N has a temperature-sensitive function that is essential for N signaling. The O-fucose monosaccharide and O-glucose glycan modification, catalyzed by Rumi, function redundantly in the activation of N signaling. We also showed that the redundant function of these two modifications is responsible for the presence of N at the cell surface. Our findings elucidate how different forms of glycosylation on a protein can influence the protein's functions. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Reusable temperature-sensitive luminescent material based on vitrified film of europium(III) β-diketonate complex (United States)

    Lapaev, Dmitry V.; Nikiforov, Victor G.; Lobkov, Vladimir S.; Knyazev, Andrey A.; Galyametdinov, Yury G.


    We have proposed a novel temperature-sensitive luminescent material which is a 20 μm thick vitrified film (sandwiched between two quartz plates) fabricated from an amorphous powder of a mesogenic europium(III) β-diketonate complex through a melt-processing technique. The film photoexcited by a 337 nm pulsed nitrogen laser displays a typical Eu3+ ion luminescence bands with the strongest peak at 612 nm and with the decay time of 537 μs at 298 K. It is obtained that both the mean luminescence intensity and the luminescence decay time at 612 nm decrease significantly with temperature increasing from 298 to 348 K; the average values of the relative and absolute temperature sensitivities of the luminescence decay time in the range of 298-348 K are -1.2%·K-1 and -6.5 μs·K-1, respectively. The thermal quenching mechanism of the luminescent properties was analyzed and discussed. The experiments showed that, the luminescent properties of the film is insensitive to oxygen, the film is photostable under UV light, there is full reversibility of the temperature-dependent luminescence intensity and the decay time, and the high luminescence brightness of the film can be observed with violet light excitation. These factors indicated that the film is promising material for reusable luminescent thermometers, suitable for long-term monitoring in the range of 298-348 K.

  1. Temperature-sensitive polymer-coated magnetic nanoparticles as a potential drug delivery system for targeted therapy of thyroid cancer. (United States)

    Koppolu, Bhanuprasanth; Bhavsar, Zarna; Wadajkar, Aniket S; Nattama, Sivaniarvindpriya; Rahimi, Maham; Nwariaku, Fiemu; Nguyen, Kytai T


    The objective of this work was to develop and investigate temperature-sensitive poly(N-isopropylacrylamide-acrylamide-allylamine)-coated iron oxide magnetic nanoparticles (TPMNPs) as possible targeted drug carriers for treatments of advanced thyroid cancer (ATC). These nanoparticles were prepared by free radical polymerization of monomers on the surface of silane-coupled iron oxide nanoparticles. In vitro studies demonstrated that TPMNPs were cytocompatible and effectively taken up by cancer cells in a dose-dependent manner. An external magnetic field significantly increased nanoparticle uptake, especially when cells were exposed to physiological flow conditions. Drug loading and release studies using doxorubicin confirmed the temperature-responsive release of drugs from nanoparticles. In addition, doxorubicin-loaded nanoparticles significantly killed ATC cells when compared to free doxorubicin. The in vitro results indicate that TPMNPs have potential as targeted and controlled drug carriers for thyroid cancer treatment.

  2. Magnetic resonance guided high-intensity focused ultrasound mediated hyperthermia improves the intratumoral distribution of temperature-sensitive liposomal doxorubicin. (United States)

    de Smet, Mariska; Hijnen, Nicole M; Langereis, Sander; Elevelt, Aaldert; Heijman, Edwin; Dubois, Ludwig; Lambin, Philippe; Grüll, Holger


    The aim of this study was to investigate the intratumoral distribution of a temperature-sensitive liposomal carrier and its encapsulated compounds, doxorubicin, and a magnetic resonance (MR) imaging contrast agent after high-intensity focused ultrasound (HIFU)-mediated hyperthermia-induced local drug release. (111)In-labeled temperature-sensitive liposomes encapsulating doxorubicin and [Gd(HPDO3A) (H(2)O)] were injected intravenously in the tail vein of rats (n = 12) bearing a subcutaneous rhabdomyosarcoma tumor on the hind leg. Immediately after the injection, local tumor hyperthermia (2 × 15 minutes) was applied using a clinical 3 T MR-HIFU system. Release of [Gd(HPDO3A)(H(2)O)] was studied in vivo by measuring the longitudinal relaxation rate R(1) with MR imaging. The presence of the liposomal carriers and the intratumoral distribution of doxorubicin were imaged ex vivo with autoradiography and fluorescence microscopy, respectively, for 2 different time points after injection (90 minutes and 48 hours). In hyperthermia-treated tumors, radiolabeled liposomes were distributed more homogeneously across the tumor than in the control tumors (coefficient of variation(hyp, 90 min) = 0.7 ± 0.2; coefficient of variation(cntrl, 90 min) = 1.1 ± 0.2). At 48 hours after injection, the liposomal accumulation in the tumor was enhanced in the hyperthermia group in comparison with the controls. A change in R(1) was observed in the HIFU-treated tumors, suggesting release of the contrast agent. Fluorescence images showed perivascular doxorubicin in control tumors, whereas in the HIFU-treated tumors, the delivered drug was spread over a much larger area and also taken up by tumor cells at a larger distance from blood vessels. Treatment with HIFU hyperthermia not only improved the immediate drug delivery, bioavailability, and intratumoral distribution but also enhanced liposomal accumulation over time. The sum of these effects may have a significant contribution to the therapeutic

  3. Evolution of vertebrate transient receptor potential vanilloid 3 channels: opposite temperature sensitivity between mammals and western clawed frogs.

    Directory of Open Access Journals (Sweden)

    Shigeru Saito


    Full Text Available Transient Receptor Potential (TRP channels serve as temperature receptors in a wide variety of animals and must have played crucial roles in thermal adaptation. The TRP vanilloid (TRPV subfamily contains several temperature receptors with different temperature sensitivities. The TRPV3 channel is known to be highly expressed in skin, where it is activated by warm temperatures and serves as a sensor to detect ambient temperatures near the body temperature of homeothermic animals such as mammals. Here we performed comprehensive comparative analyses of the TRPV subfamily in order to understand the evolutionary process; we identified novel TRPV genes and also characterized the evolutionary flexibility of TRPV3 during vertebrate evolution. We cloned the TRPV3 channel from the western clawed frog Xenopus tropicalis to understand the functional evolution of the TRPV3 channel. The amino acid sequences of the N- and C-terminal regions of the TRPV3 channel were highly diversified from those of other terrestrial vertebrate TRPV3 channels, although central portions were well conserved. In a heterologous expression system, several mammalian TRPV3 agonists did not activate the TRPV3 channel of the western clawed frog. Moreover, the frog TRPV3 channel did not respond to heat stimuli, instead it was activated by cold temperatures. Temperature thresholds for activation were about 16 °C, slightly below the lower temperature limit for the western clawed frog. Given that the TRPV3 channel is expressed in skin, its likely role is to detect noxious cold temperatures. Thus, the western clawed frog and mammals acquired opposite temperature sensitivity of the TRPV3 channel in order to detect environmental temperatures suitable for their respective species, indicating that temperature receptors can dynamically change properties to adapt to different thermal environments during evolution.

  4. Incorporating temperature-sensitive Q10 and foliar respiration acclimation algorithms modifies modeled ecosystem responses to global change (United States)

    Wythers, Kirk R.; Reich, Peter B.; Bradford, John B.


    Evidence suggests that respiration acclimation (RA) to temperature in plants can have a substantial influence on ecosystem carbon balance. To assess the influence of RA on ecosystem response variables in the presence of global change drivers, we incorporated a temperature-sensitive Q10 of respiration and foliar basal RA into the ecosystem model PnET-CN. We examined the new algorithms' effects on modeled net primary production (NPP), total canopy foliage mass, foliar nitrogen concentration, net ecosystem exchange (NEE), and ecosystem respiration/gross primary production ratios. This latter ratio more closely matched eddy covariance long-term data when RA was incorporated in the model than when not. Averaged across four boreal ecotone sites and three forest types at year 2100, the enhancement of NPP in response to the combination of rising [CO2] and warming was 9% greater when RA algorithms were used, relative to responses using fixed respiration parameters. The enhancement of NPP response to global change was associated with concomitant changes in foliar nitrogen and foliage mass. In addition, impacts of RA algorithms on modeled responses of NEE closely paralleled impacts on NPP. These results underscore the importance of incorporating temperature-sensitive Q10 and basal RA algorithms into ecosystem models. Given the current evidence that atmospheric [CO2] and surface temperature will continue to rise, and that ecosystem responses to those changes appear to be modified by RA, which is a common phenotypic adjustment, the potential for misleading results increases if models fail to incorporate RA into their carbon balance calculations.

  5. Vegetation types alter soil respiration and its temperature sensitivity at the field scale in an estuary wetland.

    Directory of Open Access Journals (Sweden)

    Guangxuan Han

    Full Text Available Vegetation type plays an important role in regulating the temporal and spatial variation of soil respiration. Therefore, vegetation patchiness may cause high uncertainties in the estimates of soil respiration for scaling field measurements to ecosystem level. Few studies provide insights regarding the influence of vegetation types on soil respiration and its temperature sensitivity in an estuary wetland. In order to enhance the understanding of this issue, we focused on the growing season and investigated how the soil respiration and its temperature sensitivity are affected by the different vegetation (Phragmites australis, Suaeda salsa and bare soil in the Yellow River Estuary. During the growing season, there were significant linear relationships between soil respiration rates and shoot and root biomass, respectively. On the diurnal timescale, daytime soil respiration was more dependent on net photosynthesis. A positive correlation between soil respiration and net photosynthesis at the Phragmites australis site was found. There were exponential correlations between soil respiration and soil temperature, and the fitted Q10 values varied among different vegetation types (1.81, 2.15 and 3.43 for Phragmites australis, Suaeda salsa and bare soil sites, respectively. During the growing season, the mean soil respiration was consistently higher at the Phragmites australis site (1.11 µmol CO2 m(-2 s(-1, followed by the Suaeda salsa site (0.77 µmol CO2 m(-2 s(-1 and the bare soil site (0.41 µmol CO2 m(-2 s(-1. The mean monthly soil respiration was positively correlated with shoot and root biomass, total C, and total N among the three vegetation patches. Our results suggest that vegetation patchiness at a field scale might have a large impact on ecosystem-scale soil respiration. Therefore, it is necessary to consider the differences in vegetation types when using models to evaluate soil respiration in an estuary wetland.

  6. Effects of different tree species on soil organic matter composition, decomposition rates and temperature sensitivities in boreal forest (United States)

    Segura, Javier; Nilsson, Mats B.; Erhagen, Björn; Sparrman, Tobias; Ilstedt, Ulrik; Schleucher, Jürgen; Öquist, Mats


    High-latitude ecosystems store a large proportion of the global soil organic matter (SOM) and its mineralization constitutes a major carbon flux to the atmosphere. It has been suggested that different tree species can significantly influence organo-chemical composition of SOM, and rate and temperature sensitivity of SOM decomposition. In this study we used surface soil samples (top 5 cm) from a field experiment where five different tree species (Pinus silvestrys L, Picea abies (L.) H. Karst., Larix decidua Mill., Betula pendula Roth, and Pinus contorta Douglas) were planted on a grass meadow in a randomized block design (n=3) ca. 40 years ago. The samples were incubated at 4, 9, 14, and 19 °C at a soil water potential of -25 kPa (previously determined as optimal water content for decomposition). CO2 production rates were measured hourly for 13 days. CO2 production rates were consequently lowest in the control plots and increased in the order Meadow< Contorta < Betula < Larix < Pinus < Picea. The values ranged between 0.03-0.1, 0.06-0.154, 0.1-0.24 and 0.13-0.36 mg CO2 g-1 OM (dw) h-1 at 4, 9, 14 and 19°C respectively. The temperature response of CO2 production corresponded to Q10s of 2.22 (±0.11), 2.22(±0.15), 2.66 (±0.18), 2.09 (±0.33), 2.38 (±0.31) and 2.31 (±0.09) for meadow, contorta, betula, larix, pinus and picea respectively. Only betula resulted in significantly higher Q10s as compared to the control plots, picea, contorta and larix treatments. These differences in tree species effects on SOM decomposition and its temperature sensitivity will be further discussed in relation to the organo-chemical composition of SOM as determined by pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) and nuclear magnetic resonance spectroscopy (NMR) techniques. We conclude that the temperature response of SOM decomposition rates is likely coupled to tree species composition and may have important implications for soil C dynamics. This finding can have

  7. Characterization of temperature-sensitive HVJ (Sendai virus) infection in Vero cells: inhibitory mechanism of viral production at 41 degrees. (United States)

    Hirayama, Etsuko; Ishida, Yo-ichi; Sugimoto, Masao; Hiraki, Akihiro; Kim, Jeman


    In a previous study, it was found that the synthesis of hemagglutinating virus of Japan (HVJ; Sendai virus)-specific proteins was inhibited at the transcriptional level at 41 degrees in LLC-MK2 cells. During an investigation of the temperature sensitivity of HVJ production in other host cells, the synthesis of HVJ-specific proteins was recognized even at 41 degrees in Vero cells. Viral production, however, was not detected, indicating the inhibition of steps after the synthesis of viral proteins. Hemadsorption activity was not detected at 41 degrees, suggesting problems with the envelope proteins, especially hemagglutinin-neuraminidase (HN) protein, at the cell membrane. Immunofluorescent staining and surface immunoprecipitation showed that HN protein was not present on the surface in spite of its localization in the cytoplasm. Further, analysis of the cell membrane fraction suggested that fusion (F) protein was integrated into the cell membrane but HN protein was not at 41 degrees. Electron microscopic observation showed that budding sites with spike structures formed and nucleocapsids assembled under the sites at 41 degrees without HN protein, although budded HVJ virions were not detected. At this time, F protein was exposed to the cell membrane and interacted with matrix and nucleocapsid proteins. The results suggested that the suppression of HVJ production at 41 degrees was due to the absence of HN protein in the membrane of Vero cells. Copyright 2003 S. Karger AG, Basel

  8. Droughts and broad-scale climate variability reflected by temperature-sensitive tree growth in the Qinling Mountains, central China. (United States)

    Liu, Na; Liu, Yu; Zhou, Qi; Bao, Guang


    The relationship between temperature and drought was investigated using the temperature-sensitive growth of Larix chinensis Beissn in the Qinling Mountains, central China. Extremely high tree-ring width index values (TRWI) agreed well with dry conditions defined by the dryness-wetness index (DWI) obtained from data in Chinese historical documents and climate-related papers between 1814 and 1956 (before the short of instrumental measurements); the reverse applied to extremely low TRWI values. The main severe drought epochs occurred from the late 1850s to the 1870s, the 1920s to 1930s and in the 2000s, whereas wet spells occurred from 1817-1827 and 1881-1886. The droughts in the 2000s exhibited a similar pattern as the ones from the 1920s to 1930s, with obviously an increasing temperature. The variation of tree growth agreed well with other reconstructed temperature series from nearby and remote regions, suggesting that Larix chinensis could respond to broad-scale climate variability. The longest cold interval, 1817-1827, could be associated with the influence of the Tambora eruption in 1815.

  9. Boundary-Layer Detection at Cryogenic Conditions Using Temperature Sensitive Paint Coupled with a Carbon Nanotube Heating Layer (United States)

    Goodman, Kyle Z.; Lipford, William E.; Watkins, Anthony Neal


    Detection of flow transition on aircraft surfaces and models can be vital to the development of future vehicles and computational methods for evaluating vehicle concepts. In testing at ambient conditions, IR thermography is ideal for this measurement. However, for higher Reynolds number testing, cryogenic facilities are often used, in which IR thermography is difficult to employ. In these facilities, temperature sensitive paint is an alternative with a temperature step introduced to enhance the natural temperature change from transition. Traditional methods for inducing the temperature step by changing the liquid nitrogen injection rate often change the tunnel conditions. Recent work has shown that adding a layer consisting of carbon nanotubes to the surface can be used to impart a temperature step on the model surface with little change in the operating conditions. Unfortunately, this system physically degraded at 130 K and lost heating capability. This paper describes a modification of this technique enabling operation down to at least 77 K, well below the temperature reached in cryogenic facilities. This is possible because the CNT layer is in a polyurethane binder. This was tested on a Natural Laminar Flow model in a cryogenic facility and transition detection was successfully visualized at conditions from 200 K to 110 K. Results were also compared with the traditional temperature step method.

  10. Temperature sensitivity and enzymatic mechanisms of soil organic matter decomposition along an altitudinal gradient on Mount Kilimanjaro. (United States)

    Blagodatskaya, Еvgenia; Blagodatsky, Sergey; Khomyakov, Nikita; Myachina, Olga; Kuzyakov, Yakov


    Short-term acceleration of soil organic matter decomposition by increasing temperature conflicts with the thermal adaptation observed in long-term studies. Here we used the altitudinal gradient on Mt. Kilimanjaro to demonstrate the mechanisms of thermal adaptation of extra- and intracellular enzymes that hydrolyze cellulose, chitin and phytate and oxidize monomers ((14)C-glucose) in warm- and cold-climate soils. We revealed that no response of decomposition rate to temperature occurs because of a cancelling effect consisting in an increase in half-saturation constants (Km), which counteracts the increase in maximal reaction rates (Vmax with temperature). We used the parameters of enzyme kinetics to predict thresholds of substrate concentration (Scrit) below which decomposition rates will be insensitive to global warming. Increasing values of Scrit, and hence stronger canceling effects with increasing altitude on Mt. Kilimanjaro, explained the thermal adaptation of polymer decomposition. The reduction of the temperature sensitivity of Vmax along the altitudinal gradient contributed to thermal adaptation of both polymer and monomer degradation. Extrapolating the altitudinal gradient to the large-scale latitudinal gradient, these results show that the soils of cold climates with stronger and more frequent temperature variation are less sensitive to global warming than soils adapted to high temperatures.

  11. Behavioural thermoregulation in a temperature-sensitive coral reef fish, the five-lined cardinalfish ( Cheilodipterus quinquelineatus) (United States)

    Nay, Tiffany J.; Johansen, Jacob L.; Habary, Adam; Steffensen, John F.; Rummer, Jodie L.


    As global temperatures increase, fish populations at low latitudes are thought to be at risk as they are adapted to narrow temperature ranges and live at temperatures close to their thermal tolerance limits. Behavioural movements, based on a preference for a specific temperature ( T pref), may provide a strategy to cope with changing conditions. A temperature-sensitive coral reef cardinalfish ( Cheilodipterus quinquelineatus) was exposed to 28 °C (average at collection site) or 32 °C (predicted end-of-century) for 6 weeks. T pref was determined using a shuttlebox system, which allowed fish to behaviourally manipulate their thermal environment. Regardless of treatment temperature, fish preferred 29.5 ± 0.25 °C, approximating summer average temperatures in the wild. However, 32 °C fish moved more frequently to correct their thermal environment than 28 °C fish, and daytime movements were more frequent than night-time movements. Understanding temperature-mediated movements is imperative for predicting how ocean warming will influence coral reef species and distribution patterns.

  12. Boundary-Layer Detection at Cryogenic Conditions Using Temperature Sensitive Paint Coupled with a Carbon Nanotube Heating Layer

    Directory of Open Access Journals (Sweden)

    Kyle Z. Goodman


    Full Text Available Detection of flow transition on aircraft surfaces and models can be vital to the development of future vehicles and computational methods for evaluating vehicle concepts. In testing at ambient conditions, IR thermography is ideal for this measurement. However, for higher Reynolds number testing, cryogenic facilities are often used, in which IR thermography is difficult to employ. In these facilities, temperature sensitive paint is an alternative with a temperature step introduced to enhance the natural temperature change from transition. Traditional methods for inducing the temperature step by changing the liquid nitrogen injection rate often change the tunnel conditions. Recent work has shown that adding a layer consisting of carbon nanotubes to the surface can be used to impart a temperature step on the model surface with little change in the operating conditions. Unfortunately, this system physically degraded at 130 K and lost heating capability. This paper describes a modification of this technique enabling operation down to at least 77 K, well below the temperature reached in cryogenic facilities. This is possible because the CNT layer is in a polyurethane binder. This was tested on a Natural Laminar Flow model in a cryogenic facility and transition detection was successfully visualized at conditions from 200 K to 110 K. Results were also compared with the traditional temperature step method.

  13. Modelling tree ring cellulose δ18O variations in two temperature-sensitive tree species from North and South America (United States)

    Lavergne, Aliénor; Gennaretti, Fabio; Risi, Camille; Daux, Valérie; Boucher, Etienne; Savard, Martine M.; Naulier, Maud; Villalba, Ricardo; Bégin, Christian; Guiot, Joël


    Oxygen isotopes in tree rings (δ18OTR) are widely used to reconstruct past climates. However, the complexity of climatic and biological processes controlling isotopic fractionation is not yet fully understood. Here, we use the MAIDENiso model to decipher the variability in δ18OTR of two temperature-sensitive species of relevant palaeoclimatological interest (Picea mariana and Nothofagus pumilio) and growing at cold high latitudes in North and South America. In this first modelling study on δ18OTR values in both northeastern Canada (53.86° N) and western Argentina (41.10° S), we specifically aim at (1) evaluating the predictive skill of MAIDENiso to simulate δ18OTR values, (2) identifying the physical processes controlling δ18OTR by mechanistic modelling and (3) defining the origin of the temperature signal recorded in the two species. Although the linear regression models used here to predict daily δ18O of precipitation (δ18OP) may need to be improved in the future, the resulting daily δ18OP values adequately reproduce observed (from weather stations) and simulated (by global circulation model) δ18OP series. The δ18OTR values of the two species are correctly simulated using the δ18OP estimation as MAIDENiso input, although some offset in mean δ18OTR levels is observed for the South American site. For both species, the variability in δ18OTR series is primarily linked to the effect of temperature on isotopic enrichment of the leaf water. We show that MAIDENiso is a powerful tool for investigating isotopic fractionation processes but that the lack of a denser isotope-enabled monitoring network recording oxygen fractionation in the soil-vegetation-atmosphere compartments limits our capacity to decipher the processes at play. This study proves that the eco-physiological modelling of δ18OTR values is necessary to interpret the recorded climate signal more reliably.

  14. Determination of heat transfer into a wedge model in a hypersonic flow using temperature-sensitive paint (United States)

    Risius, Steffen; Beck, Walter H.; Klein, Christian; Henne, Ulrich; Wagner, Alexander


    Heat loads on spacecraft traveling at hypersonic speed are of major interest for their designers. Several tests using temperature-sensitive paints (TSP) have been carried out in long duration shock tunnels to determine these heat loads; generally paint layers were thin, so that certain assumptions could be invoked to enable a good estimate of the thermal parameter ρck (a material property) to be obtained—the value of this parameter is needed to determine heat loads from the TSP. Very few measurements have been carried out in impulse facilities [viz. shock tunnels such as the High Enthalpy Shock Tunnel Göttingen (HEG)], where test times are much shorter. Presented here are TSP temperature measurements and subsequently derived heat loads on a ramp model placed in a hypersonic flow in HEG (specific enthalpy h 0 = 3.3 MJ kg-1, Mach number M = 7.4, temperature T ∞ = 277 K, density ρ ∞ = 11 g m-3). A number of fluorescence intensity images were acquired, from which, with the help of calibration data, temperature field data on the model surface were determined. From these the heat load into the surface was calculated, using an assumption of a 1D, semi-infinite heat transfer model. ρck for the paint was determined using an insitu calibration with a Medtherm coaxial thermocouple mounted on the model; Medtherm ρck is known. Finally presented are sources of various measurement uncertainties, arising from: (1) estimation of ρck; (2) intensity measurement in the chosen interrogation area; (3) paint time response.

  15. Measurement of bovine body and scrotal temperature using implanted temperature sensitive radio transmitters, data loggers and infrared thermography (United States)

    Wallage, A. L.; Gaughan, J. B.; Lisle, A. T.; Beard, L.; Collins, C. W.; Johnston, S. D.


    Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49 days. RT frequencies were scanned every 15 min, whilst DLs logged every 30 min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue samples processed for evidence of histopathology. Radio transmitters were less reliable than DLs; RTs lost >11 % of data, whilst 11 of the 12 DLs had 0 % data loss. IRI was only interpretable in 35.8 % of images recorded. Pearson correlations between DL and RT were strong for both BT ( r > 0.94, P 0.80, P surgical sutured sites when bulls were castrated, there was no evidence of testicular adhesion and normal active spermatogenesis was observed in six of the eight implanted testicles. There was no significant correlation of IRI with either DL or RT. We conclude that DLs provided to be a reliable continuous source of data for synchronous measurement of BT and ST.

  16. Characterization of the rate and temperature sensitivities of bacterial remineralization of dissolved organic phosphorus by natural populations

    Directory of Open Access Journals (Sweden)

    Angelicque E. White


    Full Text Available Production, transformation, and degradation are the principal components of the cycling of dissolved organic matter (DOM in marine systems. Heterotrophic Bacteria (and Archaea play a large part in this cycling via enzymatic decomposition and intracellular transformations of organic material to inorganic carbon (C, nitrogen (N , and phosphorus (P. The rate and magnitude of inorganic nutrient regeneration from DOM is related to the elemental composition and lability of DOM substrates as well as the nutritional needs of the mediating organisms. While many previous efforts have focused on C and N cycling of DOM, less is known in regards to the controls of organic P utilization and remineralization by natural populations of bacteria. In order to constrain the relative time scales and degradation of select dissolved organic P (DOP compounds we have conducted a series of experiments focused on (1 assessment of the short-term lability of a range of DOP compounds, (2 characterization of labile DOP remineralization rates and (3 examination of temperature sensitivities of labile DOP remineralization for varying bacterial populations. Results reinforce previous findings of monoester and polyphosphate lability and the relative recalcitrance of a model phosphonate: 2-aminoethylphosphonate. High resolution time-series of P monoester remineralization indicates decay constants on the order of 0.67-7.04 d-1 for bacterial populations isolated from coastal and open ocean surface waters. The variability of these rates is predictably related to incubation temperature and initial concentrations of heterotrophic bacteria. Additional controls on DOP hydrolysis included seasonal shifts in bacterial populations and the physiological state of bacteria at the initiation of DOP addition experiments. Composite results indicate that bacterial hydrolysis of P-monoesters exceeds bacterial P demand and thus DOP remineralization efficiency may control P availability to autotrophs.

  17. The Impact of the Temperature Sensitivity of Ecosystem Respiration on the Climate-Carbon Cycle Feedback Strength (United States)

    Hoffman, F. M.; Randerson, J. T.


    Rapidly increasing atmospheric carbon dioxide (CO2) concentrations are altering the Earth's climate. The anthropogenic perturbation of the global carbon cycle is expected to induce feedbacks on future CO2 concentrations and on the climate system. These feedbacks are highly uncertain and potentially large. Prediction of these feedbacks using Earth System Models (ESMs) requires knowledge of mechanisms connecting carbon and nutrients in the biosphere with the climate system. In order to reduce the range of uncertainty in climate predictions, model representation of feedbacks must be improved through comparisons with contemporary observations. The climate sensitivity of land carbon storage (γ L) varied by a factor of almost nine in the 11 C4MIP models (Friedlingstein et al., 2006), suggesting large uncertainties in ecosystem responses to climate change. The temperature sensitivity of terrestrial ecosystem respiration (Q10), a significant component of γ L, was recently reported to be independent of mean annual temperature, constant across biomes, and confined to values around 1.4 ± 0.1 based on observations from 60 FLUXNET sites, suggesting a weaker climate-carbon cycle than projected by most models (Mahecha et al., 2010}. Presented will be the results from a sensitivity analysis across time scales ranging from seasonal to interannual to decadal using a range of Q10 values for heterotrophic respiration (Rh) in the Community Land Model version 4 (CLM4). The sensitivity of the annual cycle of CO2 will be evaluated and compared with measurements from Globalview-CO2 sites. In addition, the effect of different Q10 values on the modeled ecosystem response to the El Niño-Southern Oscillation and on the long term trend in CO2 will be discussed.

  18. Shifts in microbial trophic strategy explain different temperature sensitivity of CO2 flux under constant and diurnally varying temperature regimes. (United States)

    Bai, Zhen; Xie, Hongtu; Kao-Kniffin, Jenny; Chen, Baodong; Shao, Pengshuai; Liang, Chao


    Understanding soil CO2 flux temperature sensitivity (Q10) is critical for predicting ecosystem-level responses to climate change. Yet, the effects of warming on microbial CO2 respiration still remain poorly understood under current Earth system models, partly as a result of thermal acclimation of organic matter decomposition. We conducted a 117-day incubation experiment under constant and diurnally varying temperature treatments based on four forest soils varying in vegetation stand and soil horizon. Our results showed that Q10 was greater under varying than constant temperature regimes. This distinction was most likely attributed to differences in the depletion of available carbon between constant high and varying high-temperature treatments, resulting in significantly higher rates of heterotrophic respiration in the varying high-temperature regime. Based on 16S rRNA gene sequencing data using Illumina, the varying high-temperature regime harbored higher prokaryotic alpha-diversity, was more dominated by the copiotrophic strategists and sustained a distinct community composition, in comparison to the constant-high treatment. We found a tightly coupled relationship between Q10 and microbial trophic guilds: the copiotrophic prokaryotes responded positively with high Q10 values, while the oligotrophs showed a negative response. Effects of vegetation stand and soil horizon consistently supported that the copiotrophic vs oligotrophic strategists determine the thermal sensitivity of CO2 flux. Our observations suggest that incorporating prokaryotic functional traits, such as shifts between copiotrophy and oligotrophy, is fundamental to our understanding of thermal acclimation of microbially mediated soil organic carbon cycling. Inclusion of microbial functional shifts may provide the potential to improve our projections of responses in microbial community and CO2 efflux to a changing environment in forest ecosystems. © FEMS 2017. All rights reserved. For permissions

  19. Effects of mutations at the stambh A locus of Drosophila melanogaster

    Indian Academy of Sciences (India)

    We report novel findings on the cytogenetic location, functional complexity and maternal and germline roles of the stambh A locus of Drosophila melanogaster. stmA is localized to polytene bands 44D1.2 on 2R. stmA mutations are of two types: temperature-sensitive (ts) adult and larval paralytic or unconditional embryonic ...

  20. Temperature-Sensitive Mutants in the Influenza A Virus RNA Polymerase: Alterations in the PA Linker Reduce Nuclear Targeting of the PB1-PA Dimer and Result in Viral Attenuation. (United States)

    Da Costa, Bruno; Sausset, Alix; Munier, Sandie; Ghounaris, Alexandre; Naffakh, Nadia; Le Goffic, Ronan; Delmas, Bernard


    The influenza virus RNA-dependent RNA polymerase catalyzes genome replication and transcription within the cell nucleus. Efficient nuclear import and assembly of the polymerase subunits PB1, PB2, and PA are critical steps in the virus life cycle. We investigated the structure and function of the PA linker (residues 197 to 256), located between its N-terminal endonuclease domain and its C-terminal structured domain that binds PB1, the polymerase core. Circular dichroism experiments revealed that the PA linker by itself is structurally disordered. A large series of PA linker mutants exhibited a temperature-sensitive (ts) phenotype (reduced viral growth at 39.5°C versus 37°C/33°C), suggesting an alteration of folding kinetic parameters. The ts phenotype was associated with a reduced efficiency of replication/transcription of a pseudoviral reporter RNA in a minireplicon assay. Using a fluorescent-tagged PB1, we observed that ts and lethal PA mutants did not efficiently recruit PB1 to reach the nucleus at 39.5°C. A protein complementation assay using PA mutants, PB1, and β-importin IPO5 tagged with fragments of the Gaussia princeps luciferase showed that increasing the temperature negatively modulated the PA-PB1 and the PA-PB1-IPO5 interactions or complex stability. The selection of revertant viruses allowed the identification of different types of compensatory mutations located in one or the other of the three polymerase subunits. Two ts mutants were shown to be attenuated and able to induce antibodies in mice. Taken together, our results identify a PA domain critical for PB1-PA nuclear import and that is a "hot spot" to engineer ts mutants that could be used to design novel attenuated vaccines. By targeting a discrete domain of the PA polymerase subunit of influenza virus, we were able to identify a series of 9 amino acid positions that are appropriate to engineer temperature-sensitive (ts) mutants. This is the first time that a large number of ts mutations were

  1. Alginate Microspheres Containing Temperature Sensitive Liposomes (TSL for MR-Guided Embolization and Triggered Release of Doxorubicin.

    Directory of Open Access Journals (Sweden)

    Merel van Elk

    Full Text Available The objective of this study was to develop and characterize alginate microspheres suitable for embolization with on-demand triggered doxorubicin (DOX release and whereby the microspheres as well as the drug releasing process can be visualized in vivo using MRI.For this purpose, barium crosslinked alginate microspheres were loaded with temperature sensitive liposomes (TSL/TSL-Ba-ms, which release their payload upon mild hyperthermia. These TSL contained DOX and [Gd(HPDO3A(H2O], a T1 MRI contrast agent, for real time visualization of the release. Empty alginate microspheres crosslinked with holmium ions (T2* MRI contrast agent, Ho-ms were mixed with TSL-Ba-ms to allow microsphere visualization. TSL-Ba-ms and Ho-ms were prepared with a homemade spray device and sized by sieving. Encapsulation of TSL in barium crosslinked microspheres changed the triggered release properties only slightly: 95% of the loaded DOX was released from free TSL vs. 86% release for TSL-Ba-ms within 30 seconds in 50% FBS at 42°C. TSL-Ba-ms (76 ± 41 μm and Ho-ms (64 ± 29 μm had a comparable size, which most likely will result in a similar in vivo tissue distribution after an i.v. co-injection and therefore Ho-ms can be used as tracer for the TSL-Ba-ms. MR imaging of a TSL-Ba-ms and Ho-ms mixture (ratio 95:5 before and after hyperthermia allowed in vitro and in vivo visualization of microsphere deposition (T2*-weighted images as well as temperature-triggered release (T1-weighted images. The [Gd(HPDO3A(H2O] release and clusters of microspheres containing holmium ions were visualized in a VX2 tumor model in a rabbit using MRI.In conclusion, these TSL-Ba-ms and Ho-ms are promising systems for real-time, MR-guided embolization and triggered release of drugs in vivo.

  2. Temperature sensitivity and basal rate of soil respiration and their determinants in temperate forests of North China.

    Directory of Open Access Journals (Sweden)

    Zhiyong Zhou

    Full Text Available The basal respiration rate at 10°C (R10 and the temperature sensitivity of soil respiration (Q10 are two premier parameters in predicting the instantaneous rate of soil respiration at a given temperature. However, the mechanisms underlying the spatial variations in R10 and Q10 are not quite clear. R10 and Q10 were calculated using an exponential function with measured soil respiration and soil temperature for 11 mixed conifer-broadleaved forest stands and nine broadleaved forest stands at a catchment scale. The mean values of R10 were 1.83 µmol CO2 m(-2 s(-1 and 2.01 µmol CO2 m(-2 s(-1, the mean values of Q10 were 3.40 and 3.79, respectively, for mixed and broadleaved forest types. Forest type did not influence the two model parameters, but determinants of R10 and Q10 varied between the two forest types. In mixed forest stands, R10 decreased greatly with the ratio of coniferous to broadleaved tree species; whereas it sharply increased with the soil temperature range and the variations in soil organic carbon (SOC, and soil total nitrogen (TN. Q10 was positively correlated with the spatial variances of herb-layer carbon stock and soil bulk density, and negatively with soil C/N ratio. In broadleaved forest stands, R10 was markedly affected by basal area and the variations in shrub carbon stock and soil phosphorus (P content; the value of Q10 largely depended on soil pH and the variations of SOC and TN. 51% of variations in both R10 and Q10 can be accounted for jointly by five biophysical variables, of which the variation in soil bulk density played an overwhelming role in determining the amplitude of variations in soil basal respiration rates in temperate forests. Overall, it was concluded that soil respiration of temperate forests was largely dependent on soil physical properties when temperature kept quite low.

  3. Old and stable soil organic matter is not necessarily chemically recalcitrant: Implications for modeling concepts and temperature sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Kleber, M.; Nico, P.S.; Plante, A.; Filley, T.; Kramer, M.; Swanston, C.; Sollins, P.


    of complex or 'recalcitrant' compounds will erroneously attribute a greater temperature sensitivity to those materials than they may actually possess.

  4. Temperature sensitive liposomes combined with thermal ablation: Effects of duration and timing of heating in mathematical models and in vivo. (United States)

    Rossmann, Christian; McCrackin, M A; Armeson, Kent E; Haemmerich, Dieter


    Temperature sensitive liposomes (TSL) are nanoparticles that rapidly release the contained drug at hyperthermic temperatures, typically above ~40°C. TSL have been combined with various heating modalities, but there is no consensus on required hyperthermia duration or ideal timing of heating relative to TSL administration. The goal of this study was to determine changes in drug uptake when heating duration and timing are varied when combining TSL with radiofrequency ablation (RF) heating. We used computer models to simulate both RF tissue heating and TSL drug delivery, to calculate spatial drug concentration maps. We simulated heating for 5, 12 and 30 min for a single RF electrode, as well as three sequential 12 min ablations for 3 electrodes placed in a triangular array. To support simulation results, we performed porcine in vivo studies in normal liver, where TSL filled with doxorubicin (TSL-Dox) at a dose of 30 mg was infused over 30 min. Following infusion, RF heating was performed in separate liver locations for either 5 min (n = 2) or 12 min (n = 2). After ablation, the animal was euthanized, and liver extracted and frozen. Liver samples were cut orthogonal to the electrode axis, and fluorescence imaging was used to visualize tissue doxorubicin distribution. Both in vivo studies and computer models demonstrate a ring-shaped drug deposition within ~1 cm of the visibly coagulated tissue. Drug uptake directly correlated with heating duration. In computer simulations, drug concentration increased by a factor of 2.2x and 4.3x when heating duration was extended from 5 to either 12, or 30 minutes, respectively. In vivo, drug concentration was by a factor of 2.4x higher at 12 vs 5 min heating duration (7.1 μg/g to 3.0 μg/g). The computer models suggest that heating should be timed to maximize area under the curve of systemic plasma concentration of encapsulated drug. Both computer models and in vivo study demonstrate that tissue drug uptake directly correlates with

  5. Genetic reconstitution of the human Adenovirus type 2 temperature-sensitive 1 mutant defective in endosomal escape

    Directory of Open Access Journals (Sweden)

    Gastaldelli Michele


    Full Text Available Abstract Human Adenoviruses infect the upper and lower respiratory tracts, the urinary and digestive tracts, lymphoid systems and heart, and give rise to epidemic conjunctivitis. More than 51 human serotypes have been identified to-date, and classified into 6 species A-F. The species C Adenoviruses Ad2 and Ad5 (Ad2/5 cause upper and lower respiratory disease, but how viral structure relates to the selection of particular infectious uptake pathways is not known. An adenovirus mutant, Ad2-ts1 had been isolated upon chemical mutagenesis in the past, and shown to have unprocessed capsid proteins. Ad2-ts1 fails to package the viral protease L3/p23, and Ad2-ts1 virions do not efficiently escape from endosomes. It had been suggested that the C22187T point mutation leading to the substitution of the conserved proline 137 to leucine (P137L in the L3/p23 protease was at least in part responsible for this phenotype. To clarify if the C22187T mutation is necessary and sufficient for the Ad2-ts1 phenotype, we sequenced the genes encoding the structural proteins of Ad2-ts1, and confirmed that the Ad2-ts1 DNA carries the point mutation C22187T. Introduction of C22187T to the wild-type Ad2 genome in a bacterial artificial chromosome (Ad2-BAC gave Ad2-BAC46 virions with the full Ad2-ts1 phenotype. Reversion of Ad2-BAC46 gave wild-type Ad2 particles indicating that P137L is necessary and sufficient for the Ad2-ts1 phenotype. The kinetics of Ad2-ts1 uptake into cells were comparable to Ad2 suggesting similar endocytic uptake mechanisms. Surprisingly, infectious Ad2 or Ad5 but not Ad2-ts1 uptake required CALM (clathrin assembly lymphoid myeloid protein, which controls clathrin-mediated endocytosis and membrane transport between endosomes and the trans-Golgi-network. The data show that no other mutations than P137L in the viral protease are necessary to give rise to particles that are defective in capsid processing and endosomal escape. This provides a basis for

  6. The microbial temperature sensitivity to warming is controlled by thermal adaptation and is independent of C-quality across a pan-continental survey (United States)

    Berglund, Eva; Rousk, Johannes


    Climate models predict that warming will result in an increased loss of soil organic matter (SOM). However, field experiments suggest that although warming results in an immediate increase in SOM turnover, the effect diminishes over time. Although the use and subsequent turnover of SOM is dominated by the soil microbial community, the underlying physiology underpinning warming responses are not considered in current climate models. It has been suggested that a reduction in the perceived quality of SOM to the microbial community, and changes in the microbial thermal adaptation, could be important feed-backs to soil warming. Thus, studies distinguishing between temperature relationships and how substrate quality influences microbial decomposition are a priority. We examined microbial communities and temperature sensitivities along a natural climate gradient including 56 independent samples from across Europe. The gradient included mean annual temperatures (MAT) from ca -4 to 18 ˚ C, along with wide spans of environmental factors known to influence microbial communities, such as pH (4.0 to 8.8), nutrients (C/N from 7 to 50), SOM (from 4 to 94%), and plant communities, etc. The extensive ranges of environmental conditions resulted in wide ranges of substrate quality, indexed as microbial respiration per unit SOM, from 5-150 μg CO2g-1 SOM g-1 h-1. We hypothesised microbial communities to (1) be adapted to the temperature of their climate, leading to warm adapted bacterial communities that were more temperature sensitive (higher Q10s) at higher MAT; (2) have temperature sensitivities affected by the quality of SOM, with higher Q10s for lower quality SOM. To determine the microbial use of SOM and its dependence on temperature, we characterized microbial temperature dependences of bacterial growth (leu inc), fungal growth (ac-in-erg) and soil respiration in all 56 sites. Temperature dependences were determined using brief (ca. 1-2 h at 25˚ C) laboratory incubation

  7. Monitoring temperature sensitivity of soil organic carbon decomposition under maize-wheat cropping systems in semi-arid India. (United States)

    Sandeep, S; Manjaiah, K M; Mayadevi, M R; Singh, A K


    Long-term storage of soil organic carbon (SOC) is essential for sustainability of agricultural ecosystems and maintaining overall environment quality as soils contain a significant part of global carbon stocks. In this study, we attempted to explain the carbon mineralization and temperature sensitivity of SOC in maize-wheat systems, a common cropping system in the semi-arid regions of India. Soil samples(0-0.15 m) from long-term experimental plots laid in split plot design with two tillage systems (conventional tillage and bed planting) and six nutrient management treatments (T 1 = control, T 2 = 120 kg urea-N/ha, T 3 = T2 (25 % N substituted by farmyard manure (FYM)), T 4 = T 2 (25 % N substituted by sewage sludge), T 5 = T 2 + crop residue, T 6 = 100 % recommended doses of N through organic source - 50 % FYM + 25 % biofertilizer + 25 % crop residue) were incubated at different temperatures (25, 30, 35, and 40 °C) to determine the thermal sensitivity parameters associated with carbon mineralization. Earlier reports suggest a selective preservation of C3-derived carbon fractions over C4 in the SOC pool, and this is the first instance where δ (13)C signatures (C4-derived carbon) were used as a qualitative measure to assess thermal sensitivity of SOC pools in the maize-wheat crop rotation systems of semi-arid India. Among the nutrient management treatments, mineral fertilizers were found to add more C4-derived carbon to the SOC pool in both the tillage systems but shows less promise in SOC stability as indicated by their lower activation energies (Ea) (14.25 kJ mol(-1)). Conventional tillage was found to mineralize 18.80 % (T 1-control at 25 °C) to 29.93 % carbon (T 3-mineral fertilizer + FYM at 40 °C) during the 150 days of incubation which was significantly higher than bed planting system (14.90 % in T 1-control at 25 °C and 21.99 % in T 6-100% organic sources at 40 °C). Organic manures, especially FYM (19

  8. Doxorubicin-induced co-assembling nanomedicines with temperature-sensitive acidic polymer and their in-situ-forming hydrogels for intratumoral administration. (United States)

    Wan, Jiangshan; Geng, Shinan; Zhao, Hao; Peng, Xiaole; Zhou, Qing; Li, Han; He, Ming; Zhao, Yanbing; Yang, Xiangliang; Xu, Huibi


    Doxorubicin (DOX)-induced co-assembling nanomedicines (D-PNAx) with temperature-sensitive PNAx triblock polymers have been developed for regional chemotherapy against liver cancer via intratumoral administration in the present work. Owing to the formation of insoluble DOX carboxylate, D-PNAx nanomedicines showed high drug-loading and entrapment efficacy via a simple mixing of doxorubicin hydrochloride and PNAx polymers. The sustained releasing profile of D-PNA100 nanomedicines indicated that only 9.4% of DOX was released within 1day, and 60% was released during 10days. Based on DOX-induced co-assembling behavior and their temperature sensitive in-situ-forming hydrogels, D-PNA100 nanomedicines showed excellent antitumor activity against H22 tumor using intratumoral administration. In contrast to that by free DOX solution (1.13±0.04 times at 9days) and blank PNA100 (2.11±0.34 times), the tumor volume treated by D-PNA100 had been falling to only 0.77±0.13 times of original tumor volume throughout the experimental period. In vivo biodistribution of DOX indicated that D-PNA100 nanomedicines exhibited much stronger DOX retention in tumor tissues than free DOX solution via intratumoral injection. D-PNA100 nanomedicines were hopeful to be developed as new temperature sensitive in-situ-forming hydrogels via i.t. injection for regional chemotherapy. Copyright © 2016. Published by Elsevier B.V.

  9. Suppressor Analysis of CRL4Cdt2 Defective and cdc48-353 Temperature Sensitive Mutants in Fission Yeast

    DEFF Research Database (Denmark)

    Marinova, Irina Nikolaeva

    SummaryPart 1CRL4Cdt2 E3 ligase is a key regulator of cellular proliferation and genome integrity, as it promotes the degradation of proteins involved in cell cycle progression, DNA replication and repair. In fission yeast the small intrinsically disordered protein Spd1 is targeted for degradation...... between Spd1 and PCNA. Our results provide evidence that excess Spd1 causes replication stress and genome instability by inhibiting PCNA. Furthermore, we examined the potential regulation of Spd1 function by Gad8-mediated phosphorylation of residue S43.Part 2Cdc48/p97 is a ring-shaped homohexameric...... chaperone-like complex involved in numerous cellular processes, including protein degradation, cell cycle control, DNA repair, and vesicle fusion. The cdc48 gene is essential in fission yeast and mutations or changes in Cdc48/p97 protein expression have been linked to neurological disorders and cancer...

  10. Effect of radiation-sensitive mutations and mutagens/carcinogens on bacterial recombination and mutagenesis. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Matney, T.S.


    Progress is reported on effects of temperature sensitive DNA-initiation mutation in E. coli K-12 mutants; the use of Bacillus subtilis transforming system as an in vitro mutagenesis system; characteristics of the E. coli lysogen used to test the permeability to polycyclic aromatic hydrocarbons; and the genetic toxicology of gentian violet. (PCS)

  11. DNA-Mediated Transfer of an RNA Polymerase II Gene: Reversion of the Temperature-Sensitive Hamster Cell Cycle Mutant TsAF8 by Mammalian DNA


    Ingles, C. James; Shales, Michael


    Treatment of the TsAF8 temperature-sensitive (TS) mutant of Syrian hamster BHK-21 cells, with calcium phosphate precipitates of genomic TS+ DNAs from a variety of mammalian cell lines permitted the selection of TS+ colonies at 40°C. TS+ transformation events were distinguished from spontaneous TS+ reversions in experiments in which α-amanitin-sensitive (AmaS) TS+ DNA was used to transform an AmaR derivative of TsAF8 cells and AmaR TS+ DNA was used to transform AmaS TsAF8 cells. In each case i...

  12. Vardarbība multfilmā "Madagaskara": satura analīze un 7-10 gadīgo bērnu auditorijas efekti


    Dardece, Baiba


    , ATSLĒGAS VĀRDI Izstrādātā bakalaura darba nosaukums ir Vardarbība Multfilmā ‘’Madagaskara’’ : satura analīze un 7 – 10 gadīgo bērnu auditorijas efekti. Teorētiskajā daļā ietverta Alberta Banduras Sociālā iemācīšanās teorija, kas skaidro agresīvas uzvedības rašanos. Teorija balstīta uz Nīderlandes profesores Patii Valkenburgas un Anglijas profesores Sonjas Livingstones veiktajiem pētījumiem par bērniem. Aplūkota multfilma kā mediju vēstījuma forma. Skaidrota 7- 10 gadīgo bērnu auditor...

  13. Temperature sensitivity of cardiac function in pelagic fishes with different vertical mobilities: yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus), mahimahi (Coryphaena hippurus), and swordfish (Xiphias gladius). (United States)

    Galli, Gina L J; Shiels, Holly A; Brill, Richard W


    We measured the temperature sensitivity, adrenergic sensitivity, and dependence on sarcoplasmic reticulum (SR) Ca(2+) of ventricular muscle from pelagic fishes with different vertical mobility patterns: bigeye tuna (Thunnus obesus), yellowfin tuna (Thunnus albacares), and mahimahi (Coryphaena hippurus) and a single specimen from swordfish (Xiphias gladius). Ventricular muscle from the bigeye tuna and mahimahi exhibited a biphasic response to an acute decrease in temperature (from 26 degrees to 7 degrees C); twitch force and kinetic parameters initially increased and then declined. The magnitude of this response was larger in the bigeye tuna than in the mahimahi. Under steady state conditions at 26 degrees C, inhibition of SR Ca(2+) release and reuptake with ryanodine and thapsigargin decreased twitch force and kinetic parameters, respectively, in the bigeye tuna only. However, the initial inotropy associated with decreasing temperature was abolished by SR inhibition in both the bigeye tuna and the mahimahi. Application of adrenaline completely reversed the effects of ryanodine and thapsigargin, but this effect was diminished at cold temperatures. In the yellowfin tuna, temperature and SR inhibition had minor effects on twitch force and kinetics, while adrenaline significantly increased these parameters. Limited data suggest that swordfish ventricular muscle responds to acute temperature reduction, SR inhibition, and adrenergic stimulation in a manner similar to that of bigeye tuna ventricular muscle. In aggregate, our results show that the temperature sensitivity, SR dependence, and adrenergic sensitivity of pelagic fish hearts are species specific and that these differences reflect species-specific vertical mobility patterns.

  14. Facile induction of apoptosis into plant cells associated with temperature-sensitive lethality shown on interspecific hybrid from the cross Nicotiana suaveolens x N. tabacum. (United States)

    Yamada, T; Marubashi, W; Niwa, M


    Two lines of suspension culture cells were obtained from a hybrid seedling of Nicotiana suaveolens Lehm. x N. tabacum L. cv. Hicks-2 expressing temperature-sensitive lethality. One of them (LH line) was inducible cell death in accordance with the lethality at 28 degrees C but not under high-temperature conditions (36 degrees C). Another one (SH line) lost the lethality and survived at 28 degrees C. The cells of LH line showed apoptotic changes when they were cultured at 28 degrees C. Fragmentation of nuclei was correlated with the lethality in the cells, as confirmed by fluorimetry of the nuclear DNA using laser scanning cytometry. Agarose gel analysis of DNA extracted from the cells expressing the lethality revealed a specific ladder pattern suggesting nucleosomal fragmentation that is one of the biochemical characteristics of apoptosis. From these facts, we confirmed that the process of cell death leading to hybrid lethality in the cells is certainly apoptosis. Hybrid cells were used in the experiments to estimate the point of no return in temperature-sensitive lethality and to examine the influence of cation in DNA fragmentation during apoptosis. The utility of hybrid cells as an experimental system for studies of hybrid lethality and apoptosis in plants was confirmed.

  15. Temperature-dependent sex-reversal by a transformer-2 gene-edited mutation in the spotted wing drosophila, Drosophila suzukii (United States)

    Female to male sex reversal was achieved in an emerging agricultural insect pest, Drosophila suzukii, by creating a temperature-sensitive point mutation in the sex-determination gene, transformer-2 (tra-2) using CRISPR/Cas9 (clustered regularly interspaced palindromic repeats/ CRISPR-associated) hom...

  16. Using Pressure- and Temperature-Sensitive Paint for Global Surface Pressure and Temperature Measurements on the Aft-Body of a Capsule Reentry Vehicle (United States)

    Watkins, A. Neal; Buck, Gregory M.; Leighty, Bradley D.; Lipford, William E.; Oglesby, Donald M.


    Pressure Sensitive Paint (PSP) and Temperature Sensitive Paint (TSP) were used to visualize and quantify the surface interactions of reaction control system (RCS) jets on the aft body of capsule reentry vehicle shapes. The first model tested was an Apollo-like configuration and was used to focus primarily on the effects of the forward facing roll and yaw jets. The second model tested was an early Orion Crew Module configuration blowing only out of its forward-most yaw jet, which was expected to have the most intense aerodynamic heating augmentation on the model surface. This paper will present the results from the experiments, which show that with proper system design, both PSP and TSP are effective tools for studying these types of interaction in hypersonic testing environments.

  17. Higher temperature sensitivity for stable than for labile soil organic carbon - Evidence from incubations of long-term bare fallow soils

    DEFF Research Database (Denmark)

    Lefèvre, Romain; Barré, Pierre; Moyano, Fernando E.


    The impact of climate change on the stability of soil organic carbon (SOC)remains a major source of uncertainty in predicting future changes in atmospheric CO2 levels. One unsettled issue is whether the mineralization response to temperature depends on SOC mineralization rate. Long-term (>25 years......) bare fallow experiments (LTBF) in which the soil is kept free of any vegetation and organic inputs, and their associated archives of soil samples represent a unique research platform to examine this issue as with increasing duration of fallow, the lability of remaining total SOC decreases. We retrieved....... The apparent activation energy (Ea) of SOC was then calculated for similar loss of CO2 at the different temperatures. The Ea was always higher for samples taken at the end of the bare-fallow period, implying a higher temperature sensitivity of stable C than of labile C. Our results provide strong evidence...

  18. High affinity and temperature sensitivity of blood oxygen binding in Pangasianodon hypophthalmus due to lack of chloride-hemoglobin allosteric interaction

    DEFF Research Database (Denmark)

    Damsgaard, Christian; Phuong, Le My; Huong, Do Thi Thanh


    , such as high temperature, affect O2 transport in air-breathing fishes, this study assessed the effects of temperature on O2 binding of blood and Hb in the economically important air-breathing fish Pangasianodon hypophthalmus. To determine blood O2 binding properties, blood was drawn from resting cannulated...... saturation P50 = 4.6 mmHg at extracellular pH 7.6 and 25°C), a high temperature sensitivity of O2 binding (apparent heat of oxygenation ΔHapp = -28.3 kcal/mol), and lacked a Root effect. Further, the data on Hb revealed weak ATP binding and a complete lack of Cl- binding to Hb, which, in part, explains...

  19. Melting in temperature sensitive suspensions (United States)

    Alsayed, Ahmed M.

    We describe two experimental studies about melting in colloidal systems. In particular we studied melting of 1-dimensional lamellar phases and 3-dimensional colloidal crystals. In the first set of experiments we prepared suspensions composed of rodlike fd virus and the thermosensitive polymer, poly(N-isopropylacrylamide). The phase diagram of this systems is temperature and concentration dependent. Using video microscopy, we directly observed melting of lamellar phases and single lamellae into nematic phase. We found that lamellar phases swell with increasing temperature before melting into the nematic phase. The highly swollen lamellae can be superheated as a result of topological nucleation barriers that slow the formation of the nematic phase. In another set of experiments we prepared colloidal crystals from thermally responsive microgel spheres. The crystals are equilibrium close-packed three-dimensional structures. Upon increasing the temperature slightly above room temperature, particle volume fraction decreased from 0.74 to less than 0.5. Using video microscopy, we observed premelting at grain boundaries and dislocations within bulk colloidal crystals. Premelting is the localized loss of crystalline order at surfaces and defects at sample volume fractions above the bulk melting transition. Particle tracking revealed increased disorder in crystalline regions bordering defects, the amount of which depends on the type of defect, distance from the defect, and particle volume fraction. In total these observations suggest that interfacial free energy is the crucial parameter for premelting in colloidal and in atomic scale crystals.

  20. Mutations in yeast calmodulin cause defects in spindle pole body functions and nuclear integrity



    Yeast calmodulin (CaM) is required for the progression of nuclear division (Ohya, Y. and Y. Anraku. 1989. Curr. Genet. 15:113-120), although the precise mechanism and physiological role of CaM in this process are unclear. In this paper we have characterized the phenotype caused by a temperature-sensitive lethal mutation (cmdl-101) in the yeast CaM. The cmdl-101 mutation expresses a carboxyl-terminal half of the yeast CaM (Met72-Cys147) under the control of an inducible GAL1 promoter. Incubati...

  1. Sustained large stimulation of soil heterotrophic respiration rate and its temperature sensitivity by soil warming in a cool-temperate forested peatland

    Directory of Open Access Journals (Sweden)

    Maricar Aguilos


    Full Text Available We conducted a soil warming experiment in a cool-temperate forested peatland in northern Japan during the snow-free seasons of 2007–2011, to determine whether the soil warming would change the heterotrophic respiration rate and its temperature sensitivity. We elevated the soil temperature by 3°C at 5-cm depth by using overhead infrared heaters and continuously measured hourly soil CO2 fluxes with a 15-channel automated chamber system. The 15 chambers were divided into three groups each with five replications for the control, unwarmed-trenched and warmed-trenched treatments. Soil warming enhanced heterotrophic respiration by 82% (mean of four seasons (2008–2011 observation±SD, 6.84±2.22 µmol C m−2 s−1 as compared to the unwarmed-trenched treatment (3.76±0.98 µmol C m−2 s−1. The sustained enhancement of heterotrophic respiration with soil warming suggests that global warming will accelerate the loss of carbon substantially more from forested peatlands than from other upland forest soils. Soil warming likewise enhanced temperature sensitivity slightly (Q 10, 3.1±0.08 and 3.3±0.06 in the four-season average in unwarmed- and warmed-trenched treatments, respectively, and significant effect was observed in 2009 (p<0.001 and 2010 (p<0.01. However, there was no significant difference in the basal respiration rate at 10°C (R 10, 2.2±0.52 and 2.8±1.2 µmol C m−2 s−1 between treatments, although the values tended to be high by warming throughout the study period. These results suggest that global warming will enhance not only the heterotrophic respiration rate itself but also its Q 10 in forests with high substrate availability and without severe water stress, and predictions for such ecosystems obtained by using models assuming no change in Q 10 are likely to underestimate the carbon release from the soil to the atmosphere in a future warmer environment.

  2. Testing the Metabolic Theory of Ecology with marine bacteria: Different temperature sensitivity of major phylogenetic groups during the spring phytoplankton bloom

    KAUST Repository

    Arandia-Gorostidi, Nestor


    Although temperature is a key driver of bacterioplankton metabolism, the effect of ocean warming on different bacterial phylogenetic groups remains unclear. Here, we conducted monthly short-term incubations with natural coastal bacterial communities over an annual cycle to test the effect of experimental temperature on the growth rates and carrying capacities of four phylogenetic groups: SAR11, Rhodobacteraceae, Gammaproteobacteria and Bacteroidetes. SAR11 was the most abundant group year-round as analysed by CARD-FISH, with maximum abundances in summer, while the other taxa peaked in spring. All groups, including SAR11, showed high temperature-sensitivity of growth rates and/or carrying capacities in spring, under phytoplankton bloom or post-bloom conditions. In that season, Rhodobacteraceae showed the strongest temperature response in growth rates, estimated here as activation energy (E, 1.43 eV), suggesting an advantage to outcompete other groups under warmer conditions. In summer E values were in general lower than 0.65 eV, the value predicted by the Metabolic Theory of Ecology (MTE). Contrary to MTE predictions, carrying capacity tended to increase with warming for all bacterial groups. Our analysis confirms that resource availability is key when addressing the temperature response of heterotrophic bacterioplankton. We further show that even under nutrient-sufficient conditions, warming differentially affected distinct bacterioplankton taxa. This article is protected by copyright. All rights reserved.

  3. Rescue at nonpermissive temperature of complementation group II temperature-sensitive mutants of vesicular stomatitis virus by uv-irradiated VSV

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, V.; Brun, G.


    Rescue is group-characteristic. The helper virus can be either the wt strain or a mutant belonging to any group of ts mutants except group II. With regard to genotype, the rescue progeny virus is temperature-sensitive and belongs to group II, and its ts II parent (ts O52(II)) can be characterized. As for phenotype, the in vitro thermal stability of rescue virions is intermediate between that of parental ts O52(II) and uv-irradiated wt virus, suggesting incorporation of some wt protein II molecules in the rescue virions. Different slopes (zero or different from zero) were seen in dose-effect curves representing rescue obtained by structural protein molecules, suggesting that protein II structural role could be distinguished from its functional role(s) by uv sensitivity. Differences in efficiency of the rescue of ts O52(II) by ts I mutants irradiated with low uv fluence may reflect their different transcribing capabilities at 39.6/sup 0/. The results are discussed taking into account the fact that the phenotype of group II mutants is characterized by an unstable nucleocapsid.

  4. Uniformity Study of Two-Functional Luminescent Dyes Adsorbed over an Anodized Aluminum Coating for Motion-Capturing Pressure- and Temperature-Sensitive Paint Imaging. (United States)

    Ishii, Masato; Miyazaki, Takeshi; Sakaue, Hirotaka


    The pressure- and temperature-sensitive paint (PSP/TSP) technique, for steady-state and unsteady-state measurements, is becoming widespread. However, unsteady quantitative measurement is still difficult because non-uniform distribution of the probes over a test model may cause errors in the results. We focus on the dipping method that applies two luminophores into a binding material to improve sensitivity uniformity over a model surface. A bullet-shaped axisymmetric test model with motion-capturing TSP was used to evaluate the sensitivity uniformity, and three dipping methods (static, convectional, and rotational) were examined. The average peak ratios in the longitudinal direction were 1.17-1.46 for static, 1.38-1.51 for convectional, and 1.42-1.45 for rotational dipping. The standard deviations in the transverse direction were the smallest for rotational (0.022-0.033), relative to static (0.086-0.104), and convectional (0.044-0.065) dipping.

  5. Enlargement of speckles of SF2/ASF due to loss of function of Smu1 is characterized in the mammalian temperature-sensitive mutant. (United States)

    Sugaya, Kimihiko; Ishihara, Yoshie; Sugaya, Keiko


    A temperature-sensitive (ts) CHO-K1 mutant cell line, tsTM18, exhibits chromosomal instability with decreased DNA synthesis at the nonpermissive temperature, 39 °C. An amino acid substitution in Smu1 underlying the ts phenotypes of tsTM18 cells was identified previously. We also found a ts defect in splicing of the unc52/perlecan gene. In the present study, we have generated cell lines expressing Smu1 tagged with green fluorescent protein (GFP) to study the dynamics of Smu1 in living cells. The hybrids complement deficiencies in tsTM18 cells and allow them to grow normally at 39 °C. GFP-tagged Smu1 is found in speckles in many discrete nucleoplasmic sites, and most of these also contained SF2/ASF. SF2/ASF is a member of the serine/arginine (SR)-rich splicing group of factors that are necessary for spliceosome assembly and can influence alternative splicing. SF2/ASF is also involved in the integrity of genome maintenance. In tsTM18 cells cultured at 39 °C, the Smu1 ts defect appears to alter SF2/ASF localization, suggesting a physiological association of Smu1 with SF2/ASF. The significant decrease of Smu1 may lead the enlargement of speckles of SF2/ASF. These data show the importance of Smu1 as a regulator of splicing and genome maintenance. © 2011 Landes Bioscience

  6. Establishment and functional characterization of a tracheal epithelial cell line RTEC11 from transgenic rats harboring temperature-sensitive simian virus 40 large T-antigen. (United States)

    Tabuchi, Yoshiaki; Doi, Takeshi; Takasaki, Ichiro; Takahashi, Ri-ichi; Ueda, Masatsugu; Suzuki, Yoshihisa; Obinata, Masuo


    A tracheal epithelial cell line RTEC11 was established from transgenic rats harboring temperature-sensitive simian virus 40 large T-antigen. The cells grew continuously at a permissive temperature of 33 degrees C but not at a non-permissive temperature of 39 degrees C. Morphological and functional investigations demonstrated that the cells were polarized epithelial cells maintaining a regulated permeability barrier function. Interestingly, the expression levels of Muc1 (mucin 1) and Scgb1a1 (uteroglobin), non-ciliated secretory cell markers, and Tubb4 (tubulin beta 4), a ciliated cell marker, were significantly increased under the cell growth-restricted condition. Global gene expression and computational network analyses demonstrated a significant genetic network associated with cellular development and differentiation in cells cultured at the non-permissive temperature. The tracheal epithelial cell line RTEC11 with unique characteristics should be useful as an in vitro model for studies of the physiological functions and gene expression of tracheal epithelial cells.

  7. Investigating the Effect of Line Dipole Magnetic Field on Hydrothermal Characteristics of a Temperature-Sensitive Magnetic Nanofluid Using Two-Phase Simulation. (United States)

    Bahiraei, Mehdi; Hangi, Morteza


    Hydrothermal characteristics of a temperature-sensitive magnetic nanofluid between two parallel plates are investigated in the presence of magnetic field produced by one or multiple line dipole(s) using the two-phase mixture model. As the nanofluid reaches the region where the magnetic field is applied, a rotation is developed due to the dependency of magnetization on temperature. This can lead to mixing in the flow and more uniform distribution of temperature due to the disturbance caused in the boundary layer, and consequently, enhancement in convective heat transfer. The results indicate that the disturbance in boundary layer adjacent to the lower wall is more significant than the upper wall. By application of the magnetic field, the convective heat transfer increases locally for both walls. Due to the intensified mixing, a sudden pressure drop occurs when the fluid reaches the region where the magnetic field is applied. For greater magnetic field strengths and lower Reynolds numbers, the improvement in convective heat transfer is more significant. For small magnetic field strengths, the effect of applying magnetic field on the upper wall is much smaller than that on the lower wall; however, this effect becomes almost the same for both walls at great magnetic field strengths.

  8. Preparation of dual-stimuli-responsive liposomes using methacrylate-based copolymers with pH and temperature sensitivities for precisely controlled release. (United States)

    Sugimoto, Takumi; Yamazaki, Naoko; Hayashi, Takaaki; Yuba, Eiji; Harada, Atsushi; Kotaka, Aki; Shinde, Chiharu; Kumei, Takayuki; Sumida, Yasushi; Fukushima, Mitsuhiro; Munekata, Yuki; Maruyama, Keiichi; Kono, Kenji


    Dual-signal-sensitive copolymers were synthesized by copolymerization of methoxy diethylene glycol methacrylate, methacrylic acid, and lauroxy tetraethylene glycol methacrylate, which respectively provide temperature sensitivity, pH sensitivity, and anchoring to liposome surfaces. These novel copolymers, with water solubility that differs depending on temperature and pH, are soluble in water under neutral pH and low-temperature conditions, but they become water-insoluble and form aggregates under acidic pH and high-temperature conditions. Liposomes modified with these copolymers exhibited enhanced content release at weakly acidic pH with increasing temperature, although no temperature-dependent content release was observed in neutral conditions. Interaction between the copolymers and the lipid monolayer at the air-water interface revealed that the copolymer chains penetrate more deeply into the monolayer with increasing temperature at acidic pH than at neutral pH, where the penetration of copolymer chains was moderate and temperature-independent at neutral pH. Interaction of the copolymer-modified liposomes with HeLa cells demonstrated that the copolymer-modified liposomes were adsorbed quickly and efficiently onto the cell surface and that they were internalized more gradually than the unmodified liposomes through endocytosis. Furthermore, the copolymer-modified liposomes enhanced the content release in endosomes with increasing temperature, but no such temperature-dependent enhancement of content release was observed for unmodified liposomes. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Overproduced ethylene causes programmed cell death leading to temperature-sensitive lethality in hybrid seedlings from the cross Nicotiana suaveolens x N. tabacum. (United States)

    Yamada, Tetsuya; Marubashi, Wataru


    Reproductive isolation mechanisms (RIMs) often become obstacles in crossbreeding. Hybrid lethality is a subtype of RIM but its physiological mechanism remains poorly elucidated. Interspecific hybrids of Nicotiana suaveolens Lehm. x N. tabacum L. cv. Hicks-2 expressed temperature-sensitive lethality. This lethality was induced by programmed cell death (PCD) that was accompanied by the characteristic changes of animal apoptosis in hybrid seedlings at 28 degrees C but not at 36 degrees C. When hybrid seedlings were cultured at 28 degrees C, DNA fragmentation started in the cotyledon, and nuclear fragmentation subsequently progressed with lethal symptoms spreading throughout the seedlings. At 28 degrees C, ethylene production in hybrid seedlings was detectable at a high level compared with the level in parental seedlings. In contrast, the ethylene production rate in hybrid seedlings cultured at 36 degrees C was equal to that in parental seedlings. Treatment with ethylene biosynthetic inhibitors, amino-oxyacetic acid and amino-ethoxyvinyl glycine, suppressed lethal symptoms and apoptotic changes, and also prolonged survival of hybrid seedlings. Thus, the increase in the ethylene production rate correlated closely with expression of lethal symptoms and apoptotic changes in hybrid seedlings. From these observations, we conclude that overproduced ethylene acts as an essential factor mediating PCD and subsequent lethality in hybrid seedlings. Furthermore, the present study has provided the first evidence that ethylene is involved in the phenomenon of hybrid lethality.

  10. Apoptotic cell death induces temperature-sensitive lethality in hybrid seedlings and calli derived from the cross of Nicotiana suaveolens x N. tabacum. (United States)

    Yamada, T; Marubashi, W; Niwa, M


    Hybrid lethality expressed in the interspecific hybrid of Nicotiana suaveolens Lehm. x N. tabacum L. cv. Hicks-2 is one of the mechanisms for reproductive isolation and it is temperature-sensitive. Apoptotic changes were detected in the cells of hybrid seedlings and calli expressing lethality at 28 degrees C but not under high-temperature conditions (36 degrees C), when the lethality is suppressed. Condensation of chromatin, fragmentation of nuclei and cytoplasmic reduction are the cytological changes associated with apoptosis leading to hybrid lethality. Fragmentation of nuclei was correlated with the lethal symptoms in both hybrid seedlings and calli, as confirmed by fluorimetry of the nuclear DNA using laser scanning cytometry. Agarose gel analysis of DNA extracted from hybrid seedlings and calli showing lethal symptoms revealed a specific ladder pattern suggesting nucleosomal fragmentation which is one of the biochemical changes of apoptosis. In-situ detection using terminal deoxyribonucleotidyl transferase-mediated dUTP-fluorescein nick end labeling (TUNEL) showed that this process occurred in distinct stages on each organ of hybrid seedlings and centripetally in hybrid calli. From these results, we confirmed that cell death inducing hybrid lethality was indeed apoptosis.

  11. Effect of Temperature-Sensitive Poloxamer Solution/Gel Material on Pericardial Adhesion Prevention: Supine Rabbit Model Study Mimicking Cardiac Surgery.

    Directory of Open Access Journals (Sweden)

    Hyun Kang

    Full Text Available We investigated the mobility of a temperature-sensitive poloxamer/Alginate/CaCl2 mixture (PACM in relation to gravity and cardiac motion and the efficacy of PACM on the prevention of pericardial adhesion in a supine rabbit model.A total of 50 rabbits were randomly divided into two groups according to materials applied after epicardial abrasion: PACM and dye mixture (group PD; n = 25 and saline as the control group (group CO; n = 25. In group PD, rabbits were maintained in a supine position with appropriate sedation, and location of mixture of PACM and dye was assessed by CT scan at the immediate postoperative period and 12 hours after surgery. The grade of adhesions was evaluated macroscopically and microscopically two weeks after surgery.In group PD, enhancement was localized in the anterior pericardial space, where PACM and dye mixture was applied, on immediate post-surgical CT scans. However, the volume of the enhancement was significantly decreased at the anterior pericardial space 12 hours later (P < .001. Two weeks after surgery, group PD had significantly lower macroscopic adhesion score (P = .002 and fibrosis score (P = .018 than did group CO. Inflammation score and expression of anti-macrophage antibody in group PD were lower than those in group CO, although the differences were not significant.In a supine rabbit model study, the anti-adhesion effect was maintained at the area of PACM application, although PACM shifted with gravity and heart motion. For more potent pericardial adhesion prevention, further research and development on the maintenance of anti-adhesion material position are required.

  12. An analysis of the influence of logistics activities on the export cold chain of temperature sensitive fruit through the Port of Cape Town

    Directory of Open Access Journals (Sweden)

    Leila L. Goedhals-Gerber


    Full Text Available Background: South Africa exports a large variety of different fruit types and cultivars worldwide. Yet, there is concern in the South African fruit industry that too much fruit and money is lost each year due to breaks along the fresh fruit export cold chain.Objective: The objective of this article was to identify the influence of logistics activities on breaks along the South African fruit export cold chain. The focus is specifically on temperature sensitive fruit, exported in refrigerated containers to Europe and the United Kingdom through the Port of Cape Town. This supply chain was selected as this was the most accessible supply chain in terms of retrieving the necessary temperature data.Method: The cold chain was investigated from the cold store, through all segments, until the Port of Cape Town. Temperature data collected with temperature monitoring devices from different fruit export supply chains of grapes, plums and pome fruit (apples and pears were analysed to identify the percentage of temperature breaks and the length of temperature breaks that occur at each segment of the cold chain.Results: The results show that a large number of breaks are experienced along South Africa’s fruit export cold chain, specifically at the interface between the cold store and the truck. In addition, the findings also show that there has been an improvement in the number of breaks experienced in the Port of Cape Town following the implementation of the NAVIS and Refcon systems.Conclusion: This article concludes by providing the fruit industry with areas that require addressing to improve operational procedures along the fruit export cold chain to help ensure that the fruit arrives at its final destination at optimal quality.

  13. Composite hydrogels with temperature sensitive heterogeneities: influence of gel matrix on the volume phase transition of embedded poly-(N-isopropylacrylamide) microgels. (United States)

    Meid, Judith; Friedrich, Tatjana; Tieke, Bernd; Lindner, Peter; Richtering, Walter


    The thermo-responsive behaviour of poly-(N-isopropylacrylamide) (PNiPAM) microgels embedded in covalently cross-linked non-temperature-sensitive polyacrylamide (PAam) hydrogel matrixes with different compositions was investigated by using small angle neutron scattering (SANS). The composition of the composite hydrogel was varied by (a) increasing the cross-linker and acrylamide concentration leading to strong hydrogel matrixes and (b) by increasing the microgel concentration to obtain composite gels with an internal structure. Additionally we synthesized composite hydrogels by using γ-irradiation as initiation for the polymerisation. This leads to the formation of chemical bonds between the PNiPAM microgels and the surrounding polyacrylamide matrix. Thus it is possible to synthesize hydrogels without an additional cross-linker, as well as pure particle networks. Some samples were prepared at two different temperatures, below and above the volume phase transition temperature of PNiPAM, resulting in highly swollen or totally collapsed microgels during the incorporation step. The volume phase transition of microgels is not influenced by a hydrogel matrix with high acrylamide concentration independent of the preparation temperature. However, an increased cross-linker concentration leads to a corset like constraint on microgel swelling. Microgels, which are embedded in the collapsed state (at 50 °C), are not able to swell upon cooling, whereas microgels embedded in the swollen state can collapse upon heating. For samples with an increased microgel concentration, the close microgel packing was disturbed by the formation of the polyacrylamide matrix. The hydrogel matrix squeezes the microgels together and leads to partial aggregation. The experiments demonstrate how composite hydrogels with stimuli-sensitive heterogeneities can be prepared such that the full responsiveness of the embedded microgels is retained while the macroscopic dimensions of the gel are not affected

  14. The effect of a temperature-sensitive poloxamer-alginate-CaCl2 mixture after strabismus surgery in a rabbit model. (United States)

    Ryu, Won Yeol; Jung, Hye Mi; Roh, Mee Sook; Kwon, Yoon Hyung; Jeung, Woo Jin; Park, Woo Chan; Rho, Sae Heun; Ahn, Hee Bae


    To determine the efficacy of a temperature-sensitive poloxamer-alginate mixture in reducing adhesions after strabismus surgery in a rabbit model. The superior rectus muscle was recessed in each of 36 eyes from 18 rabbits. One randomly assigned eye in each rabbit was treated with a poloxamer-alginate mixture (PA group); the other eye was treated with a subconjunctival injection of saline (control group). The adhesions between the superior rectus muscle, sclera, and conjunctiva were clinically evaluated by a masked observer at 1 day, 1 week, and 4 weeks after surgery. Inflammation was analyzed by hematoxylin and eosin staining and anti-CD11b staining. Late fibrosis was assessed by the Masson trichrome and α-smooth muscle actin staining. Adhesion, inflammation, and fibrosis were graded on a scale of 0-4. There was no significant between-group difference in the degree of adhesion at 1 day and 4 weeks after surgery. However, the degree of adhesion in the PA group was lower than that in the control group at postoperative week 1 (P 0.05). At postoperative week 4, inflammatory cell infiltration was reduced in the PA group (P = 0.046). A significant between-group difference in late fibrosis at postoperative week 4 was observed through the Masson trichrome (P = 0.024) and α-smooth muscle actin staining (P = 0.025). The poloxamer-alginate mixture significantly decreased adhesion after strabismus surgery in a rabbit model. Additional studies are warranted to evaluate the use of this mixture in preventing postoperative adhesions. Copyright © 2013 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

  15. [Effect of traditional Chinese medicines with different properties on thermoregulation and temperature-sensitive transient receptor potentialion channel protein of rats with yeast-induced fever]. (United States)

    Wan, Hong-Ye; Kong, Xiang-Ying; Li, Xiao-Min; Zhu, Hong-Wei; Su, Xiao-Hui; Lin, Na


    To compare the intervention effects of four traditional Chinese medicines (TCMs) with typical cold or hot property on body temperature and temperature-sensitive transient receptor potential ion channel proteins (TRPs) of rats with yeast-induced fever. The pyrexia model was induced by injecting yeast suspension subcutaneously. Totally 108 male SD rats were randomly divided into the normal group, the model group, the Rhei Radix et Rhizoma treated group, the Coptidis Rhizoma treated group, the Euodiae Fructus treated group, and the Alpiniae Officinarum Rhizoma treated group, with 18 rats in each group. At the 4 h, 8 h and 12 h after injection of yeast, the rats were sacrificed to collect their hypothalamus and dorsal root ganglion. The expressions of TRPV1 and TRPM8 were detected by immunohistochemistry and Western blot method. Compared with the normal group, after injection of yeast, the temperature of rats in the model group notably increased, and reached the peak at 8 h (P < 0.01). The TRPV1 level in hypothalamus and dorsal root ganglia (DRG) of the model group significantly increased, whereas the TRPM8 level significantly reduced. Compared with the model group, the Rhei Radix et Rhizoma group and the Coptidis Rhizoma group showed significant decrease in the high body temperature of rats caused by yeast, down-regulation in the expression of TRPV1, and up-regulation in the expression of TRPM8 (P < 0.05 or P < 0.01). Euodiae Fructus and Alpiniae Officinarum Rhizoma had no significant effect on either temperature or TRPs of fever rats. Rhei Radix et Rhizoma and Coptidis Rhizoma, both are TCMs with cold property, can reduce the temperature of fever rats induced by yeast, which may be related to their effective regulation of TRPV1 and TRPM8 in hypothalamus and DRG, while Euodiae Fructus and Alpiniae Officinarum Rhizoma had no relevant effect.

  16. Mapping Mutations on Phylogenies

    DEFF Research Database (Denmark)

    Nielsen, Rasmus


    This chapter provides a short review of recent methodologies developed for mapping mutations on phylogenies. Mapping of mutations, or character changes in general, using the maximum parsimony principle has been one of the most powerful tools in phylogenetics, and it has been used in a variety...... uncertainty in the mapping. Recently developed probabilistic methods can incorporate statistical uncertainty in the character mappings. In these methods, focus is on a probability distribution of mutational mappings instead of a single estimate of the mutational mapping....

  17. Mutations that increase the mitotic stability of minichromosomes in yeast: characterization of RAR1. (United States)

    Kearsey, S E; Edwards, J


    In an attempt to identify proteins involved in the initiation of DNA replication, we have isolated a series of Saccharomyces cerevisiae mutants in which the function of putative replication origins is affected. The phenotype of these Rar- (regulation of autonomous replication) mutants is to increase the mitotic stability of plasmids whose replication is dependent on weak ARS elements. These mutations are generally recessive and complementation analysis shows that mutations in several genes may improve the ability of weak ARS elements to function. One mutation (rar1-1) also confers temperature-sensitive growth, and thus an essential gene is affected. We have determined the DNA sequence of the RAR1 gene, which reveals an open reading frame for a 48.5 kDa protein. The RAR1 gene is linked to rna1 on chromosome XIII.

  18. Mutational landscape of yeast mutator strains. (United States)

    Serero, Alexandre; Jubin, Claire; Loeillet, Sophie; Legoix-Né, Patricia; Nicolas, Alain G


    The acquisition of mutations is relevant to every aspect of genetics, including cancer and evolution of species on Darwinian selection. Genome variations arise from rare stochastic imperfections of cellular metabolism and deficiencies in maintenance genes. Here, we established the genome-wide spectrum of mutations that accumulate in a WT and in nine Saccharomyces cerevisiae mutator strains deficient for distinct genome maintenance processes: pol32Δ and rad27Δ (replication), msh2Δ (mismatch repair), tsa1Δ (oxidative stress), mre11Δ (recombination), mec1Δ tel1Δ (DNA damage/S-phase checkpoints), pif1Δ (maintenance of mitochondrial genome and telomere length), cac1Δ cac3Δ (nucleosome deposition), and clb5Δ (cell cycle progression). This study reveals the diversity, complexity, and ultimate unique nature of each mutational spectrum, composed of punctual mutations, chromosomal structural variations, and/or aneuploidies. The mutations produced in clb5Δ/CCNB1, mec1Δ/ATR, tel1Δ/ATM, and rad27Δ/FEN1 strains extensively reshape the genome, following a trajectory dependent on previous events. It comprises the transmission of unstable genomes that lead to colony mosaicisms. This comprehensive analytical approach of mutator defects provides a model to understand how genome variations might accumulate during clonal evolution of somatic cell populations, including tumor cells.

  19. UV Signature Mutations (United States)


    Sequencing complete tumor genomes and exomes has sparked the cancer field's interest in mutation signatures for identifying the tumor's carcinogen. This review and meta-analysis discusses signatures and their proper use. We first distinguish between a mutagen's canonical mutations – deviations from a random distribution of base changes to create a pattern typical of that mutagen – and the subset of signature mutations, which are unique to that mutagen and permit inference backward from mutations to mutagen. To verify UV signature mutations, we assembled literature datasets on cells exposed to UVC, UVB, UVA, or solar simulator light (SSL) and tested canonical UV mutation features as criteria for clustering datasets. A confirmed UV signature was: ≥60% of mutations are C→T at a dipyrimidine site, with ≥5% CC→TT. Other canonical features such as a bias for mutations on the non-transcribed strand or at the 3' pyrimidine had limited application. The most robust classifier combined these features with criteria for the rarity of non-UV canonical mutations. In addition, several signatures proposed for specific UV wavelengths were limited to specific genes or species; non-signature mutations induced by UV may cause melanoma BRAF mutations; and the mutagen for sunlight-related skin neoplasms may vary between continents. PMID:25354245

  20. Mutations that affect vacuole biogenesis inhibit proliferation of the endoplasmic reticulum in Saccharomyces cerevisiae. (United States)

    Koning, Ann J; Larson, Lynnelle L; Cadera, Emily J; Parrish, Mark L; Wright, Robin L


    In yeast, increased levels of the sterol biosynthetic enzyme, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase isozyme, Hmg1p, induce assembly of nuclear-associated ER membranes called karmellae. To identify additional genes involved in karmellae assembly, we screened temperature-sensitive mutants for karmellae assembly defects. Two independently isolated, temperature-sensitive strains that were also defective for karmellae biogenesis carried mutations in VPS16, a gene involved in vacuolar protein sorting. Karmellae biogenesis was defective in all 13 other vacuole biogenesis mutants tested, although the severity of the karmellae assembly defect varied depending on the particular mutation. The hypersensitivity of 14 vacuole biogenesis mutants to tunicamycin was well correlated with pronounced defects in karmellae assembly, suggesting that the karmellae assembly defect reflected alteration of ER structure or function. Consistent with this hypothesis, seven of eight mutations causing defects in secretion also affected karmellae assembly. However, the vacuole biogenesis mutants were able to proliferate their ER in response to Hmg2p, indicating that the mutants did not have a global defect in the process of ER biogenesis. PMID:11973291

  1. Mutations that affect vacuole biogenesis inhibit proliferation of the endoplasmic reticulum in Saccharomyces cerevisiae. (United States)

    Koning, Ann J; Larson, Lynnelle L; Cadera, Emily J; Parrish, Mark L; Wright, Robin L


    In yeast, increased levels of the sterol biosynthetic enzyme, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase isozyme, Hmg1p, induce assembly of nuclear-associated ER membranes called karmellae. To identify additional genes involved in karmellae assembly, we screened temperature-sensitive mutants for karmellae assembly defects. Two independently isolated, temperature-sensitive strains that were also defective for karmellae biogenesis carried mutations in VPS16, a gene involved in vacuolar protein sorting. Karmellae biogenesis was defective in all 13 other vacuole biogenesis mutants tested, although the severity of the karmellae assembly defect varied depending on the particular mutation. The hypersensitivity of 14 vacuole biogenesis mutants to tunicamycin was well correlated with pronounced defects in karmellae assembly, suggesting that the karmellae assembly defect reflected alteration of ER structure or function. Consistent with this hypothesis, seven of eight mutations causing defects in secretion also affected karmellae assembly. However, the vacuole biogenesis mutants were able to proliferate their ER in response to Hmg2p, indicating that the mutants did not have a global defect in the process of ER biogenesis.

  2. Mitochondrial mutations in cancer. (United States)

    Brandon, M; Baldi, P; Wallace, D C


    The metabolism of solid tumors is associated with high lactate production while growing in oxygen (aerobic glycolysis) suggesting that tumors may have defects in mitochondrial function. The mitochondria produce cellular energy by oxidative phosphorylation (OXPHOS), generate reactive oxygen species (ROS) as a by-product, and regulate apoptosis via the mitochondrial permeability transition pore (mtPTP). The mitochondria are assembled from both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) genes. The mtDNA codes for 37 genes essential of OXPHOS, is present in thousands of copies per cell, and has a very high mutations rate. In humans, severe mtDNA mutations result in multisystem disease, while some functional population-specific polymorphisms appear to have permitted humans to adapt to new environments. Mutations in the nDNA-encoded mitochondrial genes for fumarate hydratase and succinate dehydrogenase have been linked to uterine leiomyomas and paragangliomas, and cancer cells have been shown to induce hexokinase II which harnesses OXPHOS adenosine triphosphate (ATP) production to drive glycolysis. Germline mtDNA mutations at nucleotides 10398 and 16189 have been associated with breast cancer and endometrial cancer. Tumor mtDNA somatic mutations range from severe insertion-deletion and chain termination mutations to mild missense mutations. Surprisingly, of the 190 tumor-specific somatic mtDNA mutations reported, 72% are also mtDNA sequence variants found in the general population. These include 52% of the tumor somatic mRNA missense mutations, 83% of the tRNA mutations, 38% of the rRNA mutations, and 85% of the control region mutations. Some associations might reflect mtDNA sequencing errors, but analysis of several of the tumor-specific somatic missense mutations with population counterparts appear legitimate. Therefore, mtDNA mutations in tumors may fall into two main classes: (1) severe mutations that inhibit OXPHOS, increase ROS production and promote tumor

  3. DNA Variations in Oculocutaneous Albinism: An Updated Mutation List and Current Outstanding Issues in Molecular Diagnostics (United States)

    Simeonov, Dimitre R.; Wang, Xinjing; Wang, Chen; Sergeev, Yuri; Dolinska, Monika; Bower, Matthew; Fischer, Roxanne; Winer, David; Dubrovsky, Genia; Balog, Joan Z.; Huizing, Marjan; Hart, Rachel; Zein, Wadih M.; Gahl, William A.; Brooks, Brian P.; Adams, David R.


    Oculocutaneous albinism (OCA) is a rare genetic disorder of melanin synthesis that results in hypopigmented hair, skin, and eyes. There are four types of OCA, caused by mutations in TYR (OCA-1), OCA2 (OCA-2), TYRP1 (OCA-3), or SLC45A2 (OCA-4). Here we report 22 novel mutations; 14 from a cohort of 61 patients seen as part of the NIH OCA Natural History Study and 8 from a prior study at the University of Minnesota. We also include a comprehensive list of almost 600 previously reported OCA mutations, along with ethnicity information, carrier frequencies, and in silico pathogenicity predictions. In addition to discussing the clinical and molecular features of OCA, we address the cases of apparent missing heritability. In our cohort, 25% of patients did not have two mutations in a single OCA gene. We demonstrate the utility of multiple detection methods to reveal mutations missed by Sanger sequencing. Finally, we review the TYR p.R402Q temperature sensitive variant and confirm its association with cases of albinism with only one identifiable TYR mutation. PMID:23504663

  4. A cost effective model for appropriate administration of red cell units and salvaging un-transfused red cell units by using temperature sensitive indicators for blood component transportation in a hospital setting

    Directory of Open Access Journals (Sweden)

    Aseem K Tiwari


    Full Text Available Background: A rule called "30-min rule" defines that red cell unit cannot be used if it has been out of blood bank refrigerator for over 30 min. This rule is useful to guide initiation of transfusion, but is inadequate for deciding whether to reuse or discard units received-back at blood transfusion services (BTS. A simple cost-effective temperature-sensitive indicator was evaluated to decide upon reuse (cold chain was uninterrupted or discard (where cold chain was interrupted in a simulation exercise. Materials and Methods: Temperature-sensitive indicators TH-F™ that irreversibly changed color from white to red demonstrated that heat excursion has occurred and the cumulative temperature has exceeded 10°C for over 30 min, were used in outdated red cells for simulating units, which are not used and received-back. These units were also tagged with a standard temperature monitoring device, which was a re-usable credit card sized device, which would log the actual time and temperature. In few units percent hemolysis was also calculated. Results: Statistically insignificant elevation in average temperature was noted in 102 simulated units at the time of return to BTS (Δ 0.04°C, despite the fact that these units were in the transport box for over 4 h. The average supernatant hemoglobin in these units was 0.24%, much below the prescribed threshold. Conclusion: Transportation of blood in controlled conditions with temperature-sensitive indicator is a cost-effective model to save blood, a precious human resource.

  5. Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity. (United States)

    Dolinska, Monika B; Kovaleva, Elena; Backlund, Peter; Wingfield, Paul T; Brooks, Brian P; Sergeev, Yuri V


    Tyrosinase (TYR) catalyzes the rate-limiting, first step in melanin production and its gene (TYR) is mutated in many cases of oculocutaneous albinism (OCA1), an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the absence of purified, active, recombinant wild-type and mutant human enzymes. The intra-melanosomal domain of human tyrosinase (residues 19-469) and two OCA1B related temperature-sensitive mutants, R422Q and R422W were expressed in insect cells and produced in T. ni larvae. The short trans-membrane fragment was deleted to avoid potential protein insolubility, while preserving all other functional features of the enzymes. Purified tyrosinase was obtained with a yield of >1 mg per 10 g of larval biomass. The protein was a monomeric glycoenzyme with maximum enzyme activity at 37°C and neutral pH. The two purified mutants when compared to the wild-type protein were less active and temperature sensitive. These differences are associated with conformational perturbations in secondary structure. The intramelanosomal domains of recombinant wild-type and mutant human tyrosinases are soluble monomeric glycoproteins with activities which mirror their in vivo function. This advance allows for the structure - function analyses of different mutant TYR proteins and correlation with their corresponding human phenotypes; it also provides an important tool to discover drugs that may improve tyrosinase activity and treat OCA1.

  6. Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity.

    Directory of Open Access Journals (Sweden)

    Monika B Dolinska

    Full Text Available Tyrosinase (TYR catalyzes the rate-limiting, first step in melanin production and its gene (TYR is mutated in many cases of oculocutaneous albinism (OCA1, an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the absence of purified, active, recombinant wild-type and mutant human enzymes.The intra-melanosomal domain of human tyrosinase (residues 19-469 and two OCA1B related temperature-sensitive mutants, R422Q and R422W were expressed in insect cells and produced in T. ni larvae. The short trans-membrane fragment was deleted to avoid potential protein insolubility, while preserving all other functional features of the enzymes. Purified tyrosinase was obtained with a yield of >1 mg per 10 g of larval biomass. The protein was a monomeric glycoenzyme with maximum enzyme activity at 37°C and neutral pH. The two purified mutants when compared to the wild-type protein were less active and temperature sensitive. These differences are associated with conformational perturbations in secondary structure.The intramelanosomal domains of recombinant wild-type and mutant human tyrosinases are soluble monomeric glycoproteins with activities which mirror their in vivo function. This advance allows for the structure - function analyses of different mutant TYR proteins and correlation with their corresponding human phenotypes; it also provides an important tool to discover drugs that may improve tyrosinase activity and treat OCA1.

  7. Enhancement of the safety of live influenza vaccine by attenuating mutations from cold-adapted hemagglutinin

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yoon Jae [Graduate Program in Biomaterials Science and Engineering, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Vaccine Translational Research Center, Yonsei University, Seoul (Korea, Republic of); Jang, Yo Han [Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Kim, Paul; Lee, Yun Ha; Lee, Young Jae [Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Vaccine Translational Research Center, Yonsei University, Seoul (Korea, Republic of); Byun, Young Ho; Lee, Kwang-Hee; Kim, Kyusik [Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Seong, Baik Lin, E-mail: [Graduate Program in Biomaterials Science and Engineering, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Vaccine Translational Research Center, Yonsei University, Seoul (Korea, Republic of)


    In our previous study, X-31ca-based H5N1 LAIVs, in particular, became more virulent in mice than the X-31ca MDV, possibly by the introduction of the surface antigens of highly pathogenic H5N1 influenza virus, implying that additional attenuation is needed in this cases to increase the safety level of the vaccine. In this report we suggest an approach to further increase the safety of LAIV through additional cold-adapted mutations in the hemagglutinin. The cold-adaptation of X-31 virus resulted in four amino acid mutations in the HA. We generated a panel of 7:1 reassortant viruses each carrying the hemagglutinins with individual single amino acid mutations. We examined their phenotypes and found a major attenuating mutation, N81K. This attenuation marker conferred additional temperature-sensitive and attenuation phenotype to the LAIV. Our data indicate that the cold-adapted mutation in the HA confers additional attenuation to the LAIV strain, without compromising its productivity and immune response. - Highlights: • Cold-adaptation process induced four amino acid mutations in the HA of X-31 virus. • The four mutations in the HA also contributed to attenuation of the X-31ca virus • N81K mutation was the most significant marker for the attenuation of X-31ca virus. • Introduction of N81K mutation into H3N2 LAIV further attenuated the vaccine. • This approach provides a useful guideline for enhancing the safety of the LAIVs.

  8. Minkowski Polynomials and Mutations

    Directory of Open Access Journals (Sweden)

    Mohammad Akhtar


    Full Text Available Given a Laurent polynomial f, one can form the period of f: this is a function of one complex variable that plays an important role in mirror symmetry for Fano manifolds. Mutations are a particular class of birational transformations acting on Laurent polynomials in two variables; they preserve the period and are closely connected with cluster algebras. We propose a higher-dimensional analog of mutation acting on Laurent polynomials f in n variables. In particular we give a combinatorial description of mutation acting on the Newton polytope P of f, and use this to establish many basic facts about mutations. Mutations can be understood combinatorially in terms of Minkowski rearrangements of slices of P, or in terms of piecewise-linear transformations acting on the dual polytope P* (much like cluster transformations. Mutations map Fano polytopes to Fano polytopes, preserve the Ehrhart series of the dual polytope, and preserve the period of f. Finally we use our results to show that Minkowski polynomials, which are a family of Laurent polynomials that give mirror partners to many three-dimensional Fano manifolds, are connected by a sequence of mutations if and only if they have the same period.

  9. A Mutation in the Bacillus subtilis rsbU Gene That Limits RNA Synthesis during Sporulation. (United States)

    Rothstein, David M; Lazinski, David; Osburne, Marcia S; Sonenshein, Abraham L


    Mutants of Bacillis subtilis that are temperature sensitive for RNA synthesis during sporulation were isolated after selection with a 32 P suicide agent. Whole-genome sequencing revealed that two of the mutants carried an identical lesion in the rsbU gene, which encodes a phosphatase that indirectly activates SigB, the stress-responsive RNA polymerase sigma factor. The mutation appeared to cause RsbU to be hyperactive, because the mutants were more resistant than the parent strain to ethanol stress. In support of this hypothesis, pseudorevertants that regained wild-type levels of sporulation at high temperature had secondary mutations that prevented expression of the mutant rsbU gene. The properties of these RsbU mutants support the idea that activation of SigB diminishes the bacterium's ability to sporulate. IMPORTANCE Most bacterial species encode multiple RNA polymerase promoter recognition subunits (sigma factors). Each sigma factor directs RNA polymerase to different sets of genes; each gene set typically encodes proteins important for responses to specific environmental conditions, such as changes in temperature, salt concentration, and nutrient availability. A selection for mutants of Bacillus subtilis that are temperature sensitive for RNA synthesis during sporulation unexpectedly yielded strains with a point mutation in rsbU , a gene that encodes a protein that normally activates sigma factor B (SigB) under conditions of salt stress. The mutation appears to cause RsbU, and therefore SigB, to be active inappropriately, thereby inhibiting, directly or indirectly, the ability of the cells to transcribe sporulation genes. Copyright © 2017 American Society for Microbiology.

  10. Mutations in GABRB3

    DEFF Research Database (Denmark)

    Møller, Rikke S; Wuttke, Thomas V; Helbig, Ingo


    OBJECTIVE: To examine the role of mutations in GABRB3 encoding the β3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. METHODS: We performed massive parallel sequencing...... of GABRB3 in 416 patients with a range of epileptic encephalopathies and childhood-onset epilepsies and recruited additional patients with epilepsy with GABRB3 mutations from other research and diagnostic programs. RESULTS: We identified 22 patients with heterozygous mutations in GABRB3, including 3...... probands from multiplex families. The phenotypic spectrum of the mutation carriers ranged from simple febrile seizures, genetic epilepsies with febrile seizures plus, and epilepsy with myoclonic-atonic seizures to West syndrome and other types of severe, early-onset epileptic encephalopathies...

  11. PRRT2 gene mutations (United States)

    Gardiner, Alice R.; Bhatia, Kailash P.; Stamelou, Maria; Dale, Russell C.; Kurian, Manju A.; Schneider, Susanne A.; Wali, G.M.; Counihan, Tim; Schapira, Anthony H.; Spacey, Sian D.; Valente, Enza-Maria; Silveira-Moriyama, Laura; Teive, Hélio A.G.; Raskin, Salmo; Sander, Josemir W.; Lees, Andrew; Warner, Tom; Kullmann, Dimitri M.; Wood, Nicholas W.; Hanna, Michael


    ABSTRACT Objective: The proline-rich transmembrane protein (PRRT2) gene was recently identified using exome sequencing as the cause of autosomal dominant paroxysmal kinesigenic dyskinesia (PKD) with or without infantile convulsions (IC) (PKD/IC syndrome). Episodic neurologic disorders, such as epilepsy, migraine, and paroxysmal movement disorders, often coexist and are thought to have a shared channel-related etiology. To investigate further the frequency, spectrum, and phenotype of PRRT2 mutations, we analyzed this gene in 3 large series of episodic neurologic disorders with PKD/IC, episodic ataxia (EA), and hemiplegic migraine (HM). Methods: The PRRT2 gene was sequenced in 58 family probands/sporadic individuals with PKD/IC, 182 with EA, 128 with HM, and 475 UK and 96 Asian controls. Results: PRRT2 genetic mutations were identified in 28 out of 58 individuals with PKD/IC (48%), 1/182 individuals with EA, and 1/128 individuals with HM. A number of loss-of-function and coding missense mutations were identified; the most common mutation found was the p.R217Pfs*8 insertion. Males were more frequently affected than females (ratio 52:32). There was a high proportion of PRRT2 mutations found in families and sporadic cases with PKD associated with migraine or HM (10 out of 28). One family had EA with HM and another large family had typical HM alone. Conclusions: This work expands the phenotype of mutations in the PRRT2 gene to include the frequent occurrence of migraine and HM with PKD/IC, and the association of mutations with EA and HM and with familial HM alone. We have also extended the PRRT2 mutation type and frequency in PKD and other episodic neurologic disorders. PMID:23077024

  12. Mutations in Lettuce Improvement


    Mou, Beiquan


    Lettuce is a major vegetable in western countries. Mutations generated genetic variations and played an important role in the domestication of the crop. Many traits derived from natural and induced mutations, such as dwarfing, early flowering, male sterility, and chlorophyll deficiency, are useful in physiological and genetic studies. Mutants were also used to develop new lettuce products including miniature and herbicide-tolerant cultivars. Mutant analysis was critical in lettuce genomic stu...

  13. Efficacy of an intranasal modified live bovine respiratory syncytial virus and temperature-sensitive parainfluenza type 3 virus vaccine in 3-week-old calves experimentally challenged with PI3V. (United States)

    Vangeel, Ilse; Ioannou, Faye; Riegler, Lutz; Salt, Jeremy S; Harmeyer, Silke S


    Two experimental parainfluenza type 3 virus (PI3V) challenge studies were undertaken to evaluate the efficacy of a single intranasal dose of an attenuated live vaccine containing modified live bovine respiratory syncytial virus (BRSV) and temperature-sensitive PI3V in 3-week-old calves. In the first study, vaccine efficacy was evaluated in colostrum deprived calves. Nasal shedding of PI3V was highly significantly reduced in vaccinated calves challenged 10 days or 21 days after vaccination. In the second study, vaccine efficacy was assessed in calves with maternal antibodies against PI3V by challenge 66 days post-vaccination. Vaccination also significantly reduced PI3V excretion after challenge in this study. In both studies, clinical signs after challenge were very mild and were not different between vaccinated and control calves.

  14. Detecting clusters of mutations.

    Directory of Open Access Journals (Sweden)

    Tong Zhou

    Full Text Available Positive selection for protein function can lead to multiple mutations within a small stretch of DNA, i.e., to a cluster of mutations. Recently, Wagner proposed a method to detect such mutation clusters. His method, however, did not take into account that residues with high solvent accessibility are inherently more variable than residues with low solvent accessibility. Here, we propose a new algorithm to detect clustered evolution. Our algorithm controls for different substitution probabilities at buried and exposed sites in the tertiary protein structure, and uses random permutations to calculate accurate P values for inferred clusters. We apply the algorithm to genomes of bacteria, fly, and mammals, and find several clusters of mutations in functionally important regions of proteins. Surprisingly, clustered evolution is a relatively rare phenomenon. Only between 2% and 10% of the genes we analyze contain a statistically significant mutation cluster. We also find that not controlling for solvent accessibility leads to an excess of clusters in terminal and solvent-exposed regions of proteins. Our algorithm provides a novel method to identify functionally relevant divergence between groups of species. Moreover, it could also be useful to detect artifacts in automatically assembled genomes.

  15. ALS2 mutations (United States)

    Schneider, Susanne A.; Carr, Lucinda; Deuschl, Guenther; Hopfner, Franziska; Stamelou, Maria; Wood, Nicholas W.; Bhatia, Kailash P.


    Objective: To determine the genetic etiology in 2 consanguineous families who presented a novel phenotype of autosomal recessive juvenile amyotrophic lateral sclerosis associated with generalized dystonia. Methods: A combination of homozygosity mapping and whole-exome sequencing in the first family and Sanger sequencing of candidate genes in the second family were used. Results: Both families were found to have homozygous loss-of-function mutations in the amyotrophic lateral sclerosis 2 (juvenile) (ALS2) gene. Conclusions: We report generalized dystonia and cerebellar signs in association with ALS2-related disease. We suggest that the ALS2 gene should be screened for mutations in patients who present with a similar phenotype. PMID:24562058


    DEFF Research Database (Denmark)


    The present invention relates to an isolated polynucleotide encoding at least a part of calmodulin and an isolated polypeptide comprising at least a part of a calmodulin protein, wherein the polynucleotide and the polypeptide comprise at least one mutation associated with a cardiac disorder...... the binding of calmodulin to ryanodine receptor 2 and use of such compound in a treatment of an individual having a cardiac disorder. The invention further provides a kit that can be used to detect specific mutations in calmodulin encoding genes....

  17. Are There Mutator Polymerases?

    Directory of Open Access Journals (Sweden)

    Miguel Garcia-Diaz


    Full Text Available DNA polymerases are involved in different cellular events, including genome replication and DNA repair. In the last few years, a large number of novel DNA polymerases have been discovered, and the biochemical analysis of their properties has revealed a long list of intriguing features. Some of these polymerases have a very low fidelity and have been suggested to play mutator roles in different processes, like translesion synthesis or somatic hypermutation. The current view of these processes is reviewed, and the current understanding of DNA polymerases and their role as mutator enzymes is discussed.

  18. Factor V Leiden Mutation and PT 20210 Mutation Test (United States)

    ... Patient Resources For Health Professionals Subscribe Search Factor V Leiden Mutation and PT 20210 Mutation Send Us ... As Activated Protein C Resistance APC Resistance Factor V R506Q PT G20210A Factor II 20210 Factor II ...

  19. Temperature sensitivity of silica micro-resonators

    Energy Technology Data Exchange (ETDEWEB)

    Ma Qiulin; Rossmann, Tobias; Guo Zhixiong [Department of Mechanical and Aerospace Engineering, Rutgers, State University of New Jersey, Piscataway, NJ 08854 (United States)], E-mail:


    Optical resonance shifts are measured against temperature changes for different silica beads ranging from 80 to 450 {mu}m in diameter. A micro-bead is fabricated by hydrogen flame fusing the tip of a single mode silica fibre/taper, and coupled to a fibre taper of submicrometre diameter. The coupling system in whispering-gallery modes is placed in an insulated cell. The air in the cell is slowly heated up from room temperature to about 10 K higher, and red shifts of a resonance wavelength during the heating process are recorded. Linear dependence of the wavelength shift versus the temperature rise is observed for all the tested micro-resonators. The measured sensitivity for beads greater than 200 {mu}m in size closely matches the analytical value based on bulk material properties of silica thermal expansion and the thermo-optic effect. For smaller micro-beads, however, the measured sensitivity increases with shrinking bead size. The ultra-high resolution of such a kind of temperature micro-sensor and its potential applications are addressed.

  20. Msx1 Mutations (United States)

    Wang, Y.; Kong, H.; Mues, G.; D’Souza, R.


    Mutations in the transcription factors PAX9 and MSX1 cause selective tooth agenesis in humans. In tooth bud mesenchyme of mice, both proteins are required for the expression of Bmp4, which is the key signaling factor for progression to the next step of tooth development. We have previously shown that Pax9 can transactivate a 2.4-kb Bmp4 promoter construct, and that most tooth-agenesis-causing PAX9 mutations impair DNA binding and Bmp4 promoter activation. We also found that Msx1 by itself represses transcription from this proximal Bmp4 promoter, and that, in combination with Pax9, it acts as a potentiator of Pax9-induced Bmp4 transactivation. This synergism of Msx1 with Pax9 is significant, because it is currently the only documented mechanism for Msx1-mediated activation of Bmp4. In this study, we investigated whether the 5 known tooth-agenesis-causing MSX1 missense mutations disrupt this Pax9-potentiation effect, or if they lead to deficiencies in protein stability, protein-protein interactions, nuclear translocation, and DNA-binding. We found that none of the studied molecular mechanisms yielded a satisfactory explanation for the pathogenic effects of the Msx1 mutations, calling for an entirely different approach to the investigation of this step of odontogenesis on the molecular level. PMID:21297014

  1. Mitochondrial mutations in cancer

    National Research Council Canada - National Science Library

    Brandon, M; Baldi, P; Wallace, D C


    ...). The mitochondria are assembled from both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) genes. The mtDNA codes for 37 genes essential of OXPHOS, is present in thousands of copies per cell, and has a very high mutations rate...

  2. Mutations in galactosemia

    Energy Technology Data Exchange (ETDEWEB)

    Reichardt, J.K.V. [Univ. of Southern California School of Medicine, Los Angeles, CA (United States)


    This Letter raises four issues concerning two papers on galactosemia published in the March 1995 of the Journal. First, table 2 in the paper by Elsas et al. incorrectly attributes seven galactose-l-phosphate uridyl transferase (GALT) mutations (S135L, L195P, K285N, N314D, R333W, R333G, and K334R). The table also fails to mention that others have reported the same two findings attributed to {open_quotes}Leslie et al.; Elsas et al. and in press{close_quotes} and {open_quotes}Leslie et al.; Elsas et al.{close_quotes} The first finding on the prevalence of the Q188R galactosemia mutation in the G/G Caucasian population has also been described by Ng et al., and the second finding on the correlation of the N314D GALT mutation with the Duarte variant was reported by Lin et al. Second, Elsas et al. suggest that the E203K and N314D mutations may {open_quotes}produce intra-allelic complementation when in cis{close_quotes}. This speculation is supported by the activity data of individual III-2 but is inconsistent with the activities of three other individuals I-1, II-1, and III-1 of the same pedigree. The GALT activity measured in these three individuals suggests a dominant negative effect of E203K in E203K-N314D chromosomes, since they all have less than normal activity. Thus, the preponderance of the data in this paper is at odds with the authors speculation. It is worth recalling that Lin et al. also identified four N314D GALT mutations on 95 galactosemic chromosomes examined. A similar situation also appears to be the case in proband III-1 (with genotype E203K-N314D/IVSC) in the Elsas et al. paper. 9 refs.

  3. Kin Selection - Mutation Balance

    DEFF Research Database (Denmark)

    Dyken, J. David Van; Linksvayer, Timothy Arnold; Wade, Michael J.


    Abstract Social conflict, in the form of intraspecific selfish "cheating" has been observed in a number of natural systems. However, a formal, evolutionary genetic theory of social cheating that provides an explanatory, predictive framework for these observations is lacking. Here we derive the kin...... selection-mutation balance, which provides an evolutionary null hypothesis for the statics and dynamics of cheating. When social interactions have linear fitness effects and Hamilton´s rule is satisfied, selection is never strong enough to eliminate recurrent cheater mutants from a population, but cheater...... lineages are transient and do not invade. Instead, cheating lineages are eliminated by kin selection but are constantly reintroduced by mutation, maintaining a stable equilibrium frequency of cheaters. The presence of cheaters at equilibrium creates a "cheater load" that selects for mechanisms of cheater...

  4. Comparación de las demandas físicas en jugadores de fútbol sub13 y sub14 en un 7:7 disputado en diferentes dimensiones

    Directory of Open Access Journals (Sweden)

    Julen Castellano


    Full Text Available El objetivo del estudio fue analizar la influencia de un juego reducido (JR con cuatro larguras diferentes en las demandas físicas en 28 jugadores infantiles de fútbol, divididos en grupos de edad sub13 y sub14. Se jugó un 7 contra 7 (incluido portero en los siguientes formatos de JR: 60x40m (JR60, 50x40m (JR50, 40x40m (JR40 y 30x40m (JR30, largo por ancho respectivamente. Las variables fueron analizadas a partir de dispositivos GPS: distancia total (DT y distancia recorrida en rangos ab-solutos (D0-7, D7-14, D14-17, D17-21 y D>21, todo en Km·h-1 y relativos (D60% de la velocidad máxima individual de velocidad, ratio trabajo:descanso (W:R, Player Load en tres (PL y dos (PL2D planos de movimiento, Exertion Index (EI, Velo-cidad máxima (Vmax y Metabolic Power (MP. Los resul-tados fueron: un aumento de las dimensiones incremen-tó las demandas físicas en todas las variables excepto en D21, lo que parece indicar que este grupo de edad mostró una mayor respuesta condicional cuando las dimensio-nes del campo así lo permitieron. Por el contrario, en valores relativos (D60% los sub13 mostraron mayor carga que sub14. La principal aplicación del estu-dio permitiría conocer las dimensiones que son adecua-das para cada categoría de edad, para que no supongan estas una limitación desde el punto de vista condicional.

  5. Septin mutations in human cancers

    Directory of Open Access Journals (Sweden)

    Elias T Spiliotis


    Full Text Available Septins are GTP-binding proteins that are evolutionarily and structurally related to the RAS oncogenes. Septin expression levels are altered in many cancers and new advances point to how abnormal septin expression may contribute to the progression of cancer. In contrast to the RAS GTPases, which are frequently mutated and actively promote tumorigenesis, little is known about the occurrence and role of septin mutations in human cancers. Here, we review septin missense mutations that are currently in the Catalog of Somatic Mutations in Cancer (COSMIC database. The majority of septin mutations occur in tumors of the large intestine, skin, endometrium and stomach. Over 25% of the annotated mutations in SEPT2, SEPT4 and SEPT9 belong to large intestine tumors. From all septins, SEPT9 and SEPT14 exhibit the highest mutation frequencies in skin, stomach and large intestine cancers. While septin mutations occur with frequencies lower than 3%, recurring mutations in several invariant and highly conserved amino acids are found across different septin paralogs and tumor types. Interestingly, a significant number of these mutations occur in the GTP-binding pocket and septin dimerization interfaces. Future studies may determine how these somatic mutations affect septin structure and function, whether they contribute to the progression of specific cancers and if they could serve as tumor-specific biomarkers.

  6. Calreticulin Mutations in Myeloproliferative Neoplasms

    Directory of Open Access Journals (Sweden)

    Noa Lavi


    Full Text Available With the discovery of the JAK2V617F mutation in patients with Philadelphia chromosome-negative (Ph− myeloproliferative neoplasms (MPNs in 2005, major advances have been made in the diagnosis of MPNs, in understanding of their pathogenesis involving the JAK/STAT pathway, and finally in the development of novel therapies targeting this pathway. Nevertheless, it remains unknown which mutations exist in approximately one-third of patients with non-mutated JAK2 or MPL essential thrombocythemia (ET and primary myelofibrosis (PMF. At the end of 2013, two studies identified recurrent mutations in the gene encoding calreticulin (CALR using whole-exome sequencing. These mutations were revealed in the majority of ET and PMF patients with non-mutated JAK2 or MPL but not in polycythemia vera patients. Somatic 52-bp deletions (type 1 mutations and recurrent 5-bp insertions (type 2 mutations in exon 9 of the CALR gene (the last exon encoding the C-terminal amino acids of the protein calreticulin were detected and found always to generate frameshift mutations. All detected mutant calreticulin proteins shared a novel amino acid sequence at the C-terminal. Mutations in CALR are acquired early in the clonal history of the disease, and they cause activation of JAK/STAT signaling. The CALR mutations are the second most frequent mutations in Ph− MPN patients after the JAK2V617F mutation, and their detection has significantly improved the diagnostic approach for ET and PMF. The characteristics of the CALR mutations as well as their diagnostic, clinical, and pathogenesis implications are discussed in this review.

  7. The use of NO2 absorption cross section temperature sensitivity to derive NO2 profile temperature and stratospheric–tropospheric column partitioning from visible direct-sun DOAS measurements

    Directory of Open Access Journals (Sweden)

    E. Spinei


    Full Text Available This paper presents a temperature sensitivity method (TESEM to accurately calculate total vertical NO2 column, atmospheric slant NO2 profile-weighted temperature (T, and to separate stratospheric and tropospheric columns from direct-sun (DS, ground-based measurements using the retrieved T. TESEM is based on differential optical absorption spectroscopy (DOAS fitting of the linear temperature-dependent NO2 absorption cross section, σ (T, regression model (Vandaele et al., 2003. Separation between stratospheric and tropospheric columns is based on the primarily bimodal vertical distribution of NO2 and an assumption that stratospheric effective temperature can be represented by temperature at 27 km ± 3 K, and tropospheric effective temperature is equal to surface temperature within 3–5 K. These assumptions were derived from the Global Modeling Initiative (GMI chemistry-transport model (CTM simulations over two northern midlatitude sites in 2011. TESEM was applied to the Washington State University Multi-Function DOAS instrument (MFDOAS measurements at four midlatitude locations with low and moderate NO2 anthropogenic emissions: (1 the Jet Propulsion Laboratory's Table Mountain Facility (JPL-TMF, CA, USA (34.38° N/117.68° W; (2 Pullman, WA, USA (46.73° N/117.17° W; (3 Greenbelt, MD, USA (38.99° N/76.84° W; and (4 Cabauw, the Netherlands (51.97° N/4.93° E during July 2007, June–July 2009, July–August and October 2011, November 2012–May 2013, respectively. NO2 T and total, stratospheric, and tropospheric NO2 vertical columns were determined over each site.

  8. Synthesis, Characteristics and Potential Application of Poly(β-Amino Ester Urethane)-Based Multiblock Co-Polymers as an Injectable, Biodegradable and pH/Temperature-Sensitive Hydrogel System. (United States)

    Huynh, Cong Truc; Nguyen, Minh Khanh; Jeong, In Ki; Kim, Sung Wan; Lee, Doo Sung


    Physical polymeric hydrogels have significant potential for use as injectable depot drug/protein-delivery systems. In this study, a series of novel injectable, biodegradable and pH/temperature-sensitive multiblock co-polymer physical hydrogels composed of poly(ethylene glycol) (PEG) and poly(β-amino ester urethane) (PEU) was synthesized by the polyaddition between the isocyanate groups of 1,6-diisocyanato hexamethylene and the hydroxyl groups of PEG and a synthesized monomer BTB (or ETE) in chloroform in the presence of dibutyltin dilaurate as a catalyst. The synthesized co-polymers were characterized by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy and gel-permeation chromatography. Aqueous solutions of the co-polymers showed a sol-to-gel phase transition with increasing pH and a gel-to-sol phase transition with increasing temperature. The gel regions covered the physiological conditions (37°C, pH 7.4) and could be controlled by changing the molecular weight of PEG, PEG/PEU ratio and co-polymer solution concentration. A gel formed rapidly in situ after injecting the co-polymer solution subcutaneously into SD rats and remained for more than 2 weeks in the body. The cytotoxicity tests confirmed the non-cytotoxicity of this co-polymer hydrogel. The controlled in vitro release of the model anticancer drug, doxorubicin, from this hydrogel occurred over a 7-day period. This hydrogel is a potential candidate for biomedical applications and drug/protein-delivery systems.

  9. BRAF mutations in conjunctival melanoma

    DEFF Research Database (Denmark)

    Larsen, Ann-Cathrine; Dahl, Christina; Dahmcke, Christina M.


    Purpose: To investigate incidence, clinicopathological features and prognosis of BRAF-mutated conjunctival melanoma in Denmark. Furthermore, to determine BRAF mutations in paired premalignant lesions and evaluate immunohistochemical BRAF V600E oncoprotein detection. Methods: Data from 139 patients...... with conjunctival melanoma (1960–2012) were collected. Archived conjunctival melanoma samples and premalignant lesions were analysed for BRAF mutations using droplet digital polymerase chain reaction (PCR). Results were associated with clinicopathological features and compared with BRAF V600E oncoprotein stainings...... with atypia. BRAF mutations were identified in 39 of 111 (35%) cases. The rate ratio of BRAF-mutated versus BRAF-wild-type melanoma did not change over time. BRAF mutations were associated with T1 stage (p = 0.007), young age (p = 0.001), male gender (p = 0.02), sun-exposed location (p = 0.01), mixed...

  10. Mutation in Aldosterone Producing Adenoma

    Directory of Open Access Journals (Sweden)

    Jian-Jhong Wang


    Full Text Available Discoveries of somatic mutations permit the recognition of subtypes of aldosterone-producing adenomas (APAs with distinct clinical presentations and pathological features. Catenin β1 (CTNNB1 mutation in APAs has been recently described and discussed in the literature. However, significant knowledge gaps still remain regarding the prevalence, clinical characteristics, pathophysiology, and outcomes in APA patients harboring CTNNB1 mutations. Aberrant activation of the Wnt/β-catenin signaling pathway will further modulate tumorigenesis. We also discuss the recent knowledge of CTNNB1 mutation in adrenal adenomas.

  11. SDH mutations in cancer. (United States)

    Bardella, Chiara; Pollard, Patrick J; Tomlinson, Ian


    The SDHA, SDHB, SDHC, SDHD genes encode the four subunits of succinate dehydrogenase (SDH; mitochondrial complex II), a mitochondrial enzyme involved in two essential energy-producing metabolic processes of the cell, the Krebs cycle and the electron transport chain. Germline loss-of-function mutations in any of the SDH genes or assembly factor (SDHAF2) cause hereditary paraganglioma/phaeochromocytoma syndrome (HPGL/PCC) through a mechanism which is largely unknown. Owing to the central function of SDH in cellular energy metabolism it is important to understand its role in tumor suppression. Here is reported an overview of genetics, clinical and molecular progress recently performed in understanding the basis of HPGL/PCC tumorigenesis. 2011 Elsevier B.V. All rights reserved.

  12. Plant mutation breeding and biotechnology

    National Research Council Canada - National Science Library

    Shu, Q. Y; Forster, Brian P; Nakagawa, H


    ... (FAO / IAEA) Division of Nuclear Techniques in Food and Agriculture, with its global coordinating and synergistic roles, that plant mutation breeding became a common tool available to plant breeders worldwide. Since these early days the Joint Division continues to play a considerable role in fostering the use of mutation techni...

  13. Sequenced alleles of the Caenorhabditis elegans sex-determining gene her-1 include a novel class of conditional promoter mutations. (United States)

    Perry, M D; Trent, C; Robertson, B; Chamblin, C; Wood, W B


    In the control of Caenorhabditis elegans sex determination, the her-1 gene must normally be activated to allow male development of XO animals and deactivated to allow hermaphrodite development of XX animals. The gene is regulated at the transcriptional level and has two nested male-specific transcripts. The larger of these encodes a small, novel, cysteine-rich protein responsible for masculinizing activity. Of the 32 extant mutant alleles, 30 cause partial or complete loss of masculinizing function (lf), while 2 are gain-of-function (gf) alleles resulting in abnormal masculinization of XX animals. We have identified the DNA sequence changes in each of these 32 alleles. Most affect the protein coding functions of the gene, but six are in the promoter region, including the two gf mutations. These two mutations may define a binding site for negative regulators of her-1. Three of the four remaining promoter mutations are single base changes that cause, surprisingly, temperature-sensitive loss of her-1 function. Such conditional promoter mutations have previously not been found among either prokaryotic or eukaryotic mutants analyzed at the molecular level.

  14. MPL mutations in myeloproliferative disorders

    DEFF Research Database (Denmark)

    Beer, Philip A.; Campbell, Peter J.; Scott, Linda M.


    Activating mutations of MPL exon 10 have been described in a minority of patients with idiopathic myelofibrosis (IMF) or essential thrombocythemia (ET), but their prevalence and clinical significance are unclear. Here we demonstrate that MPL mutations outside exon 10 are uncommon in platelet c......DNA and identify 4 different exon 10 mutations in granulocyte DNA from a retrospective cohort of 200 patients with ET or IMF. Allele-specific polymerase chain reaction was then used to genotype 776 samples from patients with ET entered into the PT-1 studies. MPL mutations were identified in 8.5% of JAK2 V617F......(-) patients and a single V617F(+) patient. Patients carrying the W515K allele had a significantly higher allele burden than did those with the W515L allele, suggesting a functional difference between the 2 variants. Compared with V617F(+) ET patients, those with MPL mutations displayed lower hemoglobin...

  15. Evolutionary Accessibility of Mutational Pathways (United States)

    Franke, Jasper; Klözer, Alexander; de Visser, J. Arjan G. M.; Krug, Joachim


    Functional effects of different mutations are known to combine to the total effect in highly nontrivial ways. For the trait under evolutionary selection (‘fitness’), measured values over all possible combinations of a set of mutations yield a fitness landscape that determines which mutational states can be reached from a given initial genotype. Understanding the accessibility properties of fitness landscapes is conceptually important in answering questions about the predictability and repeatability of evolutionary adaptation. Here we theoretically investigate accessibility of the globally optimal state on a wide variety of model landscapes, including landscapes with tunable ruggedness as well as neutral ‘holey’ landscapes. We define a mutational pathway to be accessible if it contains the minimal number of mutations required to reach the target genotype, and if fitness increases in each mutational step. Under this definition accessibility is high, in the sense that at least one accessible pathway exists with a substantial probability that approaches unity as the dimensionality of the fitness landscape (set by the number of mutational loci) becomes large. At the same time the number of alternative accessible pathways grows without bounds. We test the model predictions against an empirical 8-locus fitness landscape obtained for the filamentous fungus Aspergillus niger. By analyzing subgraphs of the full landscape containing different subsets of mutations, we are able to probe the mutational distance scale in the empirical data. The predicted effect of high accessibility is supported by the empirical data and is very robust, which we argue reflects the generic topology of sequence spaces. Together with the restrictive assumptions that lie in our definition of accessibility, this implies that the globally optimal configuration should be accessible to genome wide evolution, but the repeatability of evolutionary trajectories is limited owing to the presence of a

  16. Mutational meltdown in laboratory yeast populations

    NARCIS (Netherlands)

    Zeyl, C.; Mizesko, M.; Visser, de J.A.G.M.


    In small or repeatedly bottlenecked populations, mutations are expected to accumulate by genetic drift, causing fitness declines. In mutational meltdown models, such fitness declines further reduce population size, thus accelerating additional mutation accumulation and leading to extinction. Because

  17. Monoallelic mutation analysis (MAMA) for identifying germline mutations. (United States)

    Papadopoulos, N; Leach, F S; Kinzler, K W; Vogelstein, B


    Dissection of germline mutations in a sensitive and specific manner presents a continuing challenge. In dominantly inherited diseases, mutations occur in only one allele and are often masked by the normal allele. Here we report the development of a sensitive and specific diagnostic strategy based on somatic cell hybridization termed MAMA (monoallelic mutation analysis). We have demonstrated the utility of this strategy in two different hereditary colorectal cancer syndromes, one caused by a defective tumour suppressor gene on chromosome 5 (familial adenomatous polyposis, FAP) and the other caused by a defective mismatch repair gene on chromosome 2 (hereditary non-polyposis colorectal cancer, HNPCC).

  18. Mutations causative of familial hypercholesterolaemia

    DEFF Research Database (Denmark)

    Benn, Marianne; Watts, Gerald F; Tybjærg-Hansen, Anne


    AIMS: Ideally, familial hypercholesterolaemia (FH) is diagnosed by testing for mutations that decrease the catabolism of low-density lipoprotein (LDL) cholesterol; however, genetic testing is not universally available. The aim of the present study was to assess the frequency and predictors of FH...... causing mutations in 98 098 participants from the general population, the Copenhagen General Population Study. METHODS AND RESULTS: We genotyped for LDLR[W23X;W66G;W556S] and APOB[R3500Q] accounting for 38.7% of pathogenic FH mutations in Copenhagen. Clinical FH assessment excluded mutation information....... The prevalence of the four FH mutations was 0.18% (1:565), suggesting a total prevalence of FH mutations of 0.46% (1:217). Using the Dutch Lipid Clinic Network (DLCN) criteria, odds ratios for an FH mutation were 439 (95% CI: 170-1 138) for definite FH, 90 (53-152) for probable FH, and 18 (13-25) for possible FH...

  19. Minisequencing mitochondrial DNA pathogenic mutations

    Directory of Open Access Journals (Sweden)

    Carracedo Ángel


    Full Text Available Abstract Background There are a number of well-known mutations responsible of common mitochondrial DNA (mtDNA diseases. In order to overcome technical problems related to the analysis of complete mtDNA genomes, a variety of different techniques have been proposed that allow the screening of coding region pathogenic mutations. Methods We here propose a minisequencing assay for the analysis of mtDNA mutations. In a single reaction, we interrogate a total of 25 pathogenic mutations distributed all around the whole mtDNA genome in a sample of patients suspected for mtDNA disease. Results We have detected 11 causal homoplasmic mutations in patients suspected for Leber disease, which were further confirmed by standard automatic sequencing. Mutations m.11778G>A and m.14484T>C occur at higher frequency than expected by change in the Galician (northwest Spain patients carrying haplogroup J lineages (Fisher's Exact test, P-value Conclusion We here developed a minisequencing genotyping method for the screening of the most common pathogenic mtDNA mutations which is simple, fast, and low-cost. The technique is robust and reproducible and can easily be implemented in standard clinical laboratories.

  20. HNPCC: Six new pathogenic mutations

    Directory of Open Access Journals (Sweden)

    Epplen Joerg T


    Full Text Available Abstract Background Hereditary non-polyposis colorectal cancer (HNPCC is an autosomal dominant disease with a high risk for colorectal and endometrial cancer caused by germline mutations in DNA mismatch-repair genes (MMR. HNPCC accounts for approximately 2 to 5% of all colorectal cancers. Here we present 6 novel mutations in the DNA mismatch-repair genes MLH1, MSH2 and MSH6. Methods Patients with clinical diagnosis of HNPCC were counselled. Tumor specimen were analysed for microsatellite instability and immunohistochemistry for MLH1, MSH2 and MSH6 protein was performed. If one of these proteins was not detectable in the tumor mutation analysis of the corresponding gene was carried out. Results We identified 6 frameshift mutations (2 in MLH1, 3 in MSH2, 1 in MSH6 resulting in a premature stop: two mutations in MLH1 (c.2198_2199insAACA [p.N733fsX745], c.2076_2077delTG [p.G693fsX702], three mutations in MSH2 (c.810_811delGT [p.C271fsX282], c.763_766delAGTGinsTT [p.F255fsX282], c.873_876delGACT [p.L292fsX298] and one mutation in MSH6 (c.1421_1422dupTG [p.C475fsX480]. All six tumors tested for microsatellite instability showed high levels of microsatellite instability (MSI-H. Conclusions HNPCC in families with MSH6 germline mutations may show an age of onset that is comparable to this of patients with MLH1 and MSH2 mutations.

  1. Radiation mutation breeding

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hi Sup; Kim, Jae Sung; Kim, Jin Kyu; Shin, In Chul; Lim, Young Taek


    In order to develop an advanced technical knowledge for the selection of better mutants, some of the crops were irradiated and the mutation rate, the survival rate and the method for selction of a mutant were studied. Furthermore, this study aimed to obtain basic data applicable to the development of genetic resources by evaluation and analysis the specific character for selection of the superior mutant and its plant breeding. 1. selection of the mutant with a superior resistance against environment in the principal crops 1) New varieties of mutant rices such as Wonpyeongbyeo, Wongwangbyeo, Winmibyeo, and heogseon chalbeyeo (sticky forma) were registered in the national variety list and made an application to crop variety protection right. They are under review now. 2) We also keep on studying on the number of a grain of 8 lines of excellent mutant rice for the purpose of improvement of breeding . 3) We selected 3 lines which have a resistance to pod and stem blight in large soybean, 31 lines with small grain size and higher yield, 112 lines of soybean of cooking, 7 lines of low lipoxygenase content, and 12 lines with decreased phytic acid content by 20 % compared to the previous level. 2. Selection of advanced Mugunwha (Rose of Sharon) mutant 1) Bagseul, a new variety of mutant, was developed and 30 plantlets of it are being proliferated. 2) Fifty-three lines of a mutant having a various morphologies were selected.

  2. Bladder Cancer and Genetic Mutations. (United States)

    Zhang, Xiaoying; Zhang, Yangde


    The most common type of urinary bladder cancer is called as transitional cell carcinoma. The major risk factors for bladder cancer are environmental, tobacco smoking, exposure to toxic industrial chemicals and gases, bladder inflammation due to microbial and parasitic infections, as well as some adverse side-effects of medications. The genetic mutations in some chromosomal genes, such as FGFR3, RB1, HRAS, TP53, TSC1, and others, occur which form tumors in the urinary bladder. These genes play an important role in the regulation of cell division which prevents cells from dividing too quickly. The changes in the genes of human chromosome 9 are usually responsible for tumor in bladder cancer, but the genetic mutation of chromosome 22 can also result in bladder cancer. The identification of p53 gene mutation has been studied at NIH, Washington, DC, USA, in urine samples of bladder cancer patients. The invasive bladder cancers were determined for the presence of gene mutations on p53 suppressor gene. The 18 different bladder tumors were evaluated, and 11 (61 %) had genetic mutations of p53 gene. The bladder cancer studies have suggested that 70 % of bladder cancers involve a specific mutation in a particular gene, namely telomerase reverse transcriptase (TERT) gene. The TERT gene is involved in DNA protection, cellular aging processes, and cancer. The Urothelial carcinomas of the bladder have been described in Atlas of genetics and cytogenetics in oncology and hematology. HRAS is a proto-oncogene and has potential to cause cancer in several organs including the bladder. The TSC1 c. 1907 1908 del (E636fs) mutation in bladder cancer suggests that the location of the mutation is Exon 15 with frequency of TSC1 mutation of 11.7 %. The recent findings of BAP1 mutations have shown that it contributes to BRCA pathway alterations in bladder cancer. The discoveries of more gene mutations and new biomarkers and polymerase chain reaction bioassays for gene mutations in bladder

  3. Mutational profiling reveals PIK3CA mutations in gallbladder carcinoma

    Directory of Open Access Journals (Sweden)

    Bardeesy Nabeel


    Full Text Available Abstract Background The genetics of advanced biliary tract cancers (BTC, which encompass intra- and extra-hepatic cholangiocarcinomas as well as gallbladder carcinomas, are heterogeneous and remain to be fully defined. Methods To better characterize mutations in established known oncogenes and tumor suppressor genes we tested a mass spectrometric based platform to interrogate common cancer associated mutations across a panel of 77 formalin fixed paraffin embedded archived BTC cases. Results Mutations among three genes, KRAS, NRAS and PIK3CA were confirmed in this cohort. Activating mutations in PIK3CA were identified exclusively in GBC (4/32, 12.5%. KRAS mutations were identified in 3 (13% intra-hepatic cholangiocarcinomas and 1 (33% perihillar cholangiocarcinoma but were not identified in gallbladder carcinomas and extra-hepatic cholangiocarcinoma. Conclusions The presence of activating mutations in PIK3CA specifically in GBC has clinical implications in both the diagnosis of this cancer type, as well as the potential utility of targeted therapies such as PI3 kinase inhibitors.

  4. Dominant negative consequences of a hERG 1b-specific mutation associated with intrauterine fetal death. (United States)

    Jones, David K; Liu, Fang; Dombrowski, Natasha; Joshi, Sunita; Robertson, Gail A


    The human ether-a-go-go related gene (hERG) encodes two subunits, hERG 1a and hERG 1b, that combine in vivo to conduct the rapid delayed rectifier potassium current (IKr). Reduced IKr slows cardiac action potential (AP) repolarization and is an underlying cause of cardiac arrhythmias associated with long QT syndrome (LQTS). Although the physiological importance of hERG 1b has been elucidated, the effects of hERG 1b disease mutations on cardiac IKr and AP behavior have not been described. To explore the disease mechanism of a 1b-specific mutation associated with a case of intrauterine fetal death, we examined the effects of the 1b-R25W mutation on total protein, trafficking and membrane current levels in HEK293 cells at physiological temperatures. By all measures the 1b-R25W mutation conferred diminished expression, and exerted a temperature-sensitive, dominant-negative effect over the WT hERG 1a protein with which it was co-expressed. Membrane currents were reduced by 60% with no apparent effect on voltage dependence or deactivation kinetics. The dominant-negative effects of R25W were demonstrated in iPSC-CMs, where 1b-R25W transfection diminished native IKr compared to controls. R25W also slowed AP repolarization, and increased AP triangulation and variability in iPSC-CMs, reflecting cellular manifestations of pro-arrhythmia. These data demonstrate that R25W is a dominant-negative mutation with significant pathophysiological consequences, and provide the first direct link between hERG 1b mutation and cardiomyocyte dysfunction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Markov models for accumulating mutations

    CERN Document Server

    Beerenwinkel, Niko


    We introduce and analyze a waiting time model for the accumulation of genetic changes. The continuous time conjunctive Bayesian network is defined by a partially ordered set of mutations and by the rate of fixation of each mutation. The partial order encodes constraints on the order in which mutations can fixate in the population, shedding light on the mutational pathways underlying the evolutionary process. We study a censored version of the model and derive equations for an EM algorithm to perform maximum likelihood estimation of the model parameters. We also show how to select the maximum likelihood poset. The model is applied to genetic data from different cancers and from drug resistant HIV samples, indicating implications for diagnosis and treatment.

  6. PPARγ mutations, lipodystrophy and diabetes. (United States)

    Astapova, Olga; Leff, Todd


    The focus of this review is the lipodystrophy syndrome caused by mutation in the PPARγ nuclear receptor - partial familial lipodystrophy FPLD3. To provide a broader context for how these mutations act to generate the clinical features of partial lipodystrophy we will review the basic biology of PPARγ and also survey the set PPARγ genetic variants that do not cause lipodystrophy, but are nonetheless associated with clinically related syndromes, specifically type 2 diabetes.

  7. Gene mutations in hepatocellular adenomas

    DEFF Research Database (Denmark)

    Raft, Marie B; Jørgensen, Ernö N; Vainer, Ben


    is associated with bi-allelic mutations in the TCF1 gene and morphologically has marked steatosis. β-catenin activating HCA has increased activity of the Wnt/β-catenin pathway and is associated with possible malignant transformation. Inflammatory HCA is characterized by an oncogene-induced inflammation due....... This review offers an overview of the reported gene mutations associated with hepatocellular adenomas together with a discussion of the diagnostic and prognostic value....

  8. A mutation in protein phosphatase 2A regulatory subunit A affects auxin transport in Arabidopsis (United States)

    Garbers, C.; DeLong, A.; Deruere, J.; Bernasconi, P.; Soll, D.; Evans, M. L. (Principal Investigator)


    The phytohormone auxin controls processes such as cell elongation, root hair development and root branching. Tropisms, growth curvatures triggered by gravity, light and touch, are also auxin-mediated responses. Auxin is synthesized in the shoot apex and transported through the stem, but the molecular mechanism of auxin transport is not well understood. Naphthylphthalamic acid (NPA) and other inhibitors of auxin transport block tropic curvature responses and inhibit root and shoot elongation. We have isolated a novel Arabidopsis thaliana mutant designated roots curl in NPA (rcn1). Mutant seedlings exhibit altered responses to NPA in root curling and hypocotyl elongation. Auxin efflux in mutant seedlings displays increased sensitivity to NPA. The rcn1 mutation was transferred-DNA (T-DNA) tagged and sequences flanking the T-DNA insert were cloned. Analysis of the RCN1 cDNA reveals that the T-DNA insertion disrupts a gene for the regulatory A subunit of protein phosphatase 2A (PP2A-A). The RCN1 gene rescues the rcn1 mutant phenotype and also complements the temperature-sensitive phenotype of the Saccharomyces cerevisiae PP2A-A mutation, tpd3-1. These data implicate protein phosphatase 2A in the regulation of auxin transport in Arabidopsis.

  9. HFE mutations in the elderly. (United States)

    Willis, Gavin; Wimperis, Jennie Z; Smith, Katy; Fellows, Ian W; Jennings, Barbara A


    Most individuals diagnosed with hereditary hemochromatosis have mutations in both copies of the HFE gene, with such mutations being common in populations of north European origin. The number of individuals currently diagnosed and treated for hemochromatosis is small relative to the number carrying two HFE mutations. Studies searching for undiagnosed hemochromatosis cases among disease cohorts have generally failed to find the number of cases that would be expected if disease were the commonest outcome for individuals with two C282Y HFE mutations. Our aim was to test the hypothesis that individuals with two HFE mutations would be under-represented in an elderly population because many would have died from disease caused by hemochromatosis before they reached old age. This is a cross-sectional study of elderly patients referred for full blood counts at the Norfolk and Norwich University Hospital. We screened blood samples from 1,000 elderly men (aged 85 and over) and women (aged 89 and over) for the C282Y, H63D, and S65C mutations of the HFE gene. We also analyzed any recent laboratory data relevant to signs of hemochromatosis. None of the ten possible genotypes was significantly under- or over-represented compared to the expected frequency calculated from the Hardy-Weinberg equation. Four C282Y homozygotes were found. There were few significant differences in the laboratory findings between the genotypes. Our data suggest that most people with HFE mutations survive to old age and do not suffer from signs of iron overload and hemochromatosis.

  10. Common Β- Thalassaemia Mutations in

    Directory of Open Access Journals (Sweden)

    P Azarfam


    Full Text Available Introduction: β –Thalassaemia was first explained by Thomas Cooly as Cooly’s anaemia in 1925. The β- thalassaemias are hereditary autosomal disorders with decreased or absent β-globin chain synthesis. The most common genetic defects in β-thalassaemias are caused by point mutations, micro deletions or insertions within the β-globin gene. Material and Methods: In this research , 142 blood samples (64 from childrens hospital of Tabriz , 15 samples from Shahid Gazi hospital of Tabriz , 18 from Urumia and 45 samples from Aliasghar hospital of Ardebil were taken from thalassaemic patients (who were previously diagnosed .Then 117 non-familial samples were selected . The DNA of the lymphocytes of blood samples was extracted by boiling and Proteinase K- SDS procedure, and mutations were detected by ARMS-PCR methods. Results: From the results obtained, eleven most common mutations,most of which were Mediterranean mutations were detected as follows; IVS-I-110(G-A, IVS-I-1(G-A ،IVS-I-5(G-C ,Frameshift Codon 44 (-C,( codon5(-CT,IVS-1-6(T-C, IVS-I-25(-25bp del ,Frameshift 8.9 (+G ,IVS-II-1(G-A ,Codon 39(C-T, Codon 30(G-C the mutations of the samples were defined. The results showed that Frameshift 8.9 (+G, IVS-I-110 (G-A ,IVS-II-I(G-A, IVS-I-5(G-C, IVS-I-1(G-A , Frameshift Codon 44(-C , codon5(-CT , IVS-1-6(T-C , IVS-I-25(-25bp del with a frequency of 29.9%, 25.47%,17.83%, 7.00%, 6.36% , 6.63% , 3.8% , 2.5% , 0.63% represented the most common mutations in North - west Iran. No mutations in Codon 39(C-T and Codon 30(G-C were detected. Cunclusion: The frequency of the same mutations in patients from North - West of Iran seems to be different as compared to other regions like Turkey, Pakistan, Lebanon and Fars province of Iran. The pattern of mutations in this region is more or less the same as in the Mediterranean region, but different from South west Asia and East Asia.

  11. SQSTM1 Mutations and Glaucoma.

    Directory of Open Access Journals (Sweden)

    Todd E Scheetz

    Full Text Available Glaucoma is the most common cause of irreversible blindness worldwide. One subset of glaucoma, normal tension glaucoma (NTG occurs in the absence of high intraocular pressure. Mutations in two genes, optineurin (OPTN and TANK binding kinase 1 (TBK1, cause familial NTG and have known roles in the catabolic cellular process autophagy. TKB1 encodes a kinase that phosphorylates OPTN, an autophagy receptor, which ultimately activates autophagy. The sequestosome (SQSTM1 gene also encodes an autophagy receptor and also is a target of TBK1 phosphorylation. Consequently, we hypothesized that mutations in SQSTM1 may also cause NTG. We tested this hypothesis by searching for glaucoma-causing mutations in a cohort of NTG patients (n = 308 and matched controls (n = 157 using Sanger sequencing. An additional 1098 population control samples were also analyzed using whole exome sequencing. A total of 17 non-synonymous mutations were detected which were not significantly skewed between cases and controls when analyzed separately, or as a group (p > 0.05. These data suggest that SQSTM1 mutations are not a common cause of NTG.

  12. Canavan disease: a novel mutation. (United States)

    Schober, Harald; Luetschg, Juerg; Hoeliner, Isabella; Kalb, Stefanie; Simma, Burkhard


    Canavan disease, an autosomal recessive inherited leukodystrophy caused by an aspartoacylase deficiency, is common among children of Ashkenazi Jewish descent. We report on a non-Jewish female infant who presented at age 6 months with progressive macrocephaly and developmental delay. A sequence analysis of the aspartoacylase gene revealed compound heterozygosity for a known mutation and for the mutation c.432G>A in exon 2, which has not yet been described in Canavan disease. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Analysis of the fitness effect of compensatory mutations


    Zhang, Liqing; Watson, Layne T.


    This paper extends previous work on the Darwinian evolutionary fitness effect of the fixation of deleterious mutations by incorporating compensatory mutations, which are mutations (deleterious by themselves) that ameliorate other deleterious mutations, thus reducing the genetic load of populations. Since having compensatory mutations essentially changes the distributional shapes of deleterious mutations, the effect of compensatory mutations is studied by comparing distributions of deleterious...

  14. Domain landscapes of somatic mutations in cancer. (United States)

    Nehrt, Nathan L; Peterson, Thomas A; Park, DoHwan; Kann, Maricel G


    Large-scale tumor sequencing projects are now underway to identify genetic mutations that drive tumor initiation and development. Most studies take a gene-based approach to identifying driver mutations, highlighting genes mutated in a large percentage of tumor samples as those likely to contain driver mutations. However, this gene-based approach usually does not consider the position of the mutation within the gene or the functional context the position of the mutation provides. Here we introduce a novel method for mapping mutations to distinct protein domains, not just individual genes, in which they occur, thus providing the functional context for how the mutation contributes to disease. Furthermore, aggregating mutations from all genes containing a specific protein domain enables the identification of mutations that are rare at the gene level, but that occur frequently within the specified domain. These highly mutated domains potentially reveal disruptions of protein function necessary for cancer development. We mapped somatic mutations from the protein coding regions of 100 colon adenocarcinoma tumor samples to the genes and protein domains in which they occurred, and constructed topographical maps to depict the "mutational landscapes" of gene and domain mutation frequencies. We found significant mutation frequency in a number of genes previously known to be somatically mutated in colon cancer patients including APC, TP53 and KRAS. In addition, we found significant mutation frequency within specific domains located in these genes, as well as within other domains contained in genes having low mutation frequencies. These domain "peaks" were enriched with functions important to cancer development including kinase activity, DNA binding and repair, and signal transduction. Using our method to create the domain landscapes of mutations in colon cancer, we were able to identify somatic mutations with high potential to drive cancer development. Interestingly, the


    Indian Academy of Sciences (India)

    The Rate of Spontaneous Mutation of a Human Gene. (Published on 1935 J. Genet. 31, 317-326). J. B. S. Haldane. J. Genet. Classic Volume 83 Issue 3 December 2004 pp 235-244. Fulltext. Click here to view fulltext PDF. Permanent link: Author Affiliations.

  16. Causative mutations in FKBP10

    African Journals Online (AJOL)

    Prior to the current project, contact was made with medical colleagues in other centres in SA, and they were offered molecular genetic screening for mutations in their patients with OI-3 by the. Division of Human Genetics at UCT. The clinicians caring for affected persons with OI-3 and their families submitted blood or saliva.

  17. Thalassemia mutations in Gaziantep, Turkey

    African Journals Online (AJOL)



    Feb 22, 2010 ... thalassemia mutation (3.7 single gene deletions in 1 patient, anti-3.7 gene triplication in 4 patients) was determined at the same time. Finally ... inherited disorder of hemoglobin (Hb) synthesis in the world, with gene ..... Peykar DP, Akhavan-Niaki H, Tamaddoni A, Ghawidel-Parsa S, Naieni. KH, Rahmani M ...

  18. Isocitrate dehydrogenase mutations in gliomas (United States)

    Waitkus, Matthew S.; Diplas, Bill H.; Yan, Hai


    Over the last decade, extraordinary progress has been made in elucidating the underlying genetic causes of gliomas. In 2008, our understanding of glioma genetics was revolutionized when mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) were identified in the vast majority of progressive gliomas and secondary glioblastomas (GBMs). IDH enzymes normally catalyze the decarboxylation of isocitrate to generate α-ketoglutarate (αKG), but recurrent mutations at Arg132 of IDH1 and Arg172 of IDH2 confer a neomorphic enzyme activity that catalyzes reduction of αKG into the putative oncometabolite D-2-hydroxyglutate (D2HG). D2HG inhibits αKG-dependent dioxygenases and is thought to create a cellular state permissive to malignant transformation by altering cellular epigenetics and blocking normal differentiation processes. Herein, we discuss the relevant literature on mechanistic studies of IDH1/2 mutations in gliomas, and we review the potential impact of IDH1/2 mutations on molecular classification and glioma therapy. PMID:26188014

  19. identification of a novel mutation

    Indian Academy of Sciences (India)

    in children and it mostly affects the liver, muscle and heart. (Koshy et al. 2006). GSDs can be differentiated ... novel mutation; Azeri Turkish sequencing. Journal of Genetics, DOI 10.1007/s12041-016-0734-y, Vol. ... patients were screened by their physicians at a children's hospital in Tabriz between February 2011 and July ...

  20. Rapid evolution of the human mutation spectrum. (United States)

    Harris, Kelley; Pritchard, Jonathan K


    DNA is a remarkably precise medium for copying and storing biological information. This high fidelity results from the action of hundreds of genes involved in replication, proofreading, and damage repair. Evolutionary theory suggests that in such a system, selection has limited ability to remove genetic variants that change mutation rates by small amounts or in specific sequence contexts. Consistent with this, using SNV variation as a proxy for mutational input, we report here that mutational spectra differ substantially among species, human continental groups and even some closely related populations. Close examination of one signal, an increased TCC→TTC mutation rate in Europeans, indicates a burst of mutations from about 15,000 to 2000 years ago, perhaps due to the appearance, drift, and ultimate elimination of a genetic modifier of mutation rate. Our results suggest that mutation rates can evolve markedly over short evolutionary timescales and suggest the possibility of mapping mutational modifiers.

  1. Prevalent mutations in fatty acid oxidation disorders

    DEFF Research Database (Denmark)

    Gregersen, N; Andresen, B S; Bross, P


    UNLABELLED: The mutational spectrum in a given disease-associated gene is often comprised of a large number of different mutations, of which a single or a few are present in a large proportion of diseased individuals. Such prevalent mutations are known in four genes of the fatty acid oxidation...... carrying the prevalent 985A > G mutation are at risk of developing life-threatening attacks. In SCAD/ethylmalonic aciduria, on the other hand, the presence of the prevalent susceptibility variations, 625A and 511T, in the SCAD gene seems to require additional genetic and cellular factors to be present...... in order to result in a phenotype. For the prevalent mutations in the LCHAD and CPT II genes further data are needed to evaluate the penetrance and risk of manifest disease when carrying these mutations. CONCLUSION: Assessment of the prevalence of a prevalent mutation in the mutation spectrum...

  2. Identifying driver mutations in sequenced cancer genomes

    DEFF Research Database (Denmark)

    Raphael, Benjamin J; Dobson, Jason R; Oesper, Layla


    High-throughput DNA sequencing is revolutionizing the study of cancer and enabling the measurement of the somatic mutations that drive cancer development. However, the resulting sequencing datasets are large and complex, obscuring the clinically important mutations in a background of errors, noise......, and random mutations. Here, we review computational approaches to identify somatic mutations in cancer genome sequences and to distinguish the driver mutations that are responsible for cancer from random, passenger mutations. First, we describe approaches to detect somatic mutations from high-throughput DNA...... sequencing data, particularly for tumor samples that comprise heterogeneous populations of cells. Next, we review computational approaches that aim to predict driver mutations according to their frequency of occurrence in a cohort of samples, or according to their predicted functional impact on protein...

  3. Mutation Rates of STR Systems in Danes

    DEFF Research Database (Denmark)

    Andersen, Kim Emil; Bøttcher, Susanne Gammelgaard; Christensen, Susanne

    rates on different STR loci. In the cases where mutations had occured, we found no interaction between kits, STRA loci or sexes. However, we found differences in the mutation rates between the sexes, meaning that the differences in male and female mutation rates can be assumed constant over STR loci...... and kits. Sex and STR locus specific mutation rates were estimated with 95% confidence limits by the method of Clopper and Pearson (1934)....

  4. Adaptive mutation: has the unicorn landed? (United States)

    Foster, P L


    Reversion of an episomal Lac- allele during lactose selection has been studied as a model for adaptive mutation. Although recent results show that the mutations that arise during selection are not "adaptive" in the original sense, the mutagenic mechanism that produces these mutations may nonetheless be of evolutionary significance. In addition, a transient mutational state induced in a subpopulation of starving cells could provide a species with a mechanism for adaptive evolution. PMID:9560365

  5. Biological evolution model with conditional mutation rates (United States)

    Saakian, David B.; Ghazaryan, Makar; Bratus, Alexander; Hu, Chin-Kun


    We consider an evolution model, in which the mutation rates depend on the structure of population: the mutation rates from lower populated sequences to higher populated sequences are reduced. We have applied the Hamilton-Jacobi equation method to solve the model and calculate the mean fitness. We have found that the modulated mutation rates, directed to increase the mean fitness.

  6. DNA evolved to minimize frameshift mutations


    Agoni, Valentina


    Point mutations can surely be dangerous but what is worst than to lose the reading frame?! Does DNA evolved a strategy to try to limit frameshift mutations?! Here we investigate if DNA sequences effectively evolved a system to minimize frameshift mutations analyzing the transcripts of proteins with high molecular weights.

  7. BRCA1 and BRCA2 Mutations (United States)

    patient education Fact Sheet PFS007: BRCA1 and BRCA2 Mutations OCTOBER 2017 BRCA1 and BRCA2 Mutations Cancer is caused by several different factors. A ... parent to child. Changes in genes are called mutations . Hereditary breast and ovarian cancer (HBOC) syndrome is ...

  8. Heterogeneity within AML with CEBPA mutations; only CEBPA double mutations, but not single CEBPA mutations are associated with favourable prognosis


    Pabst, T; Eyholzer, M; Fos, J; Mueller, B U


    CCAAT/enhancer binding protein alpha (CEBPA) mutations in AML are associated with favourable prognosis and are divided into N- and C-terminal mutations. The majority of AML patients have both types of mutations. We assessed the prognostic significance of single (n=7) and double (n=12) CEBPA mutations among 224 AML patients. Double CEBPA mutations conferred a decisively favourable overall (P=0.006) and disease-free survival (P=0.013). However, clinical outcome of patients with single CEBPA mut...

  9. PAX6 mutations: genotype-phenotype correlations

    Directory of Open Access Journals (Sweden)

    Hanson Isabel M


    Full Text Available Abstract Background The PAX6 protein is a highly conserved transcriptional regulator that is important for normal ocular and neural development. In humans, heterozygous mutations of the PAX6 gene cause aniridia (absence of the iris and related developmental eye diseases. PAX6 mutations are archived in the Human PAX6 Allelic Variant Database, which currently contains 309 records, 286 of which are mutations in patients with eye malformations. Results We examined the records in the Human PAX6 Allelic Variant Database and documented the frequency of different mutation types, the phenotypes associated with different mutation types, the contribution of CpG transitions to the PAX6 mutation spectrum, and the distribution of chain-terminating mutations in the open reading frame. Mutations that introduce a premature termination codon into the open reading frame are predominantly associated with aniridia; in contrast, non-aniridia phenotypes are typically associated with missense mutations. Four CpG dinucleotides in exons 8, 9, 10 and 11 are major mutation hotspots, and transitions at these CpG's account for over half of all nonsense mutations in the database. Truncating mutations are distributed throughout the PAX6 coding region, except for the last half of exon 12 and the coding part of exon 13, where they are completely absent. The absence of truncating mutations in the 3' part of the coding region is statistically significant and is consistent with the idea that nonsense-mediated decay acts on PAX6 mutant alleles. Conclusion The PAX6 Allelic Variant Database is a valuable resource for studying genotype-phenotype correlations. The consistent association of truncating mutations with the aniridia phenotype, and the distribution of truncating mutations in the PAX6 open reading frame, suggests that nonsense-mediated decay acts on PAX6 mutant alleles.

  10. Mutation Clusters from Cancer Exome. (United States)

    Kakushadze, Zura; Yu, Willie


    We apply our statistically deterministic machine learning/clustering algorithm *K-means (recently developed in to 10,656 published exome samples for 32 cancer types. A majority of cancer types exhibit a mutation clustering structure. Our results are in-sample stable. They are also out-of-sample stable when applied to 1389 published genome samples across 14 cancer types. In contrast, we find in- and out-of-sample instabilities in cancer signatures extracted from exome samples via nonnegative matrix factorization (NMF), a computationally-costly and non-deterministic method. Extracting stable mutation structures from exome data could have important implications for speed and cost, which are critical for early-stage cancer diagnostics, such as novel blood-test methods currently in development.

  11. Mutation models for DVI analysis. (United States)

    Ricciardi, F; Slooten, K


    In recent years, the use of DNA data for personal identification has become a crucial feature for forensic applications such as disaster victim identification (DVI). Computational methods to cope with these kinds of problems must be designed to handle large scale events with a high number of victims, obtaining likelihood ratios and posterior odds with respect to different identification hypotheses. Trying to minimize identification error rates (i.e., false negatives and false positives), a number of computational methods, based either on the choice between alternative mutation models or on the adoption of a different strategy, are proposed and evaluated. Using simulation of DNA profiles, our goal is to suggest which is the most appropriate way to address likelihood ratio computation in DVI cases, especially to be able to efficiently deal with complicating issues such as mutations or null alleles, considering that data about these latter are limited and fragmentary. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Pathogenic mitochondrial DNA point mutations

    Directory of Open Access Journals (Sweden)

    N. A. Litvinova


    Full Text Available Cell energy metabolic disorders, the basis for which is mitochondrial insufficiency caused by mitochondrial DNA (mtDNA point mutations, give rise to a broad spectrum of clinical manifestations so the purpose of this review is to analyze the recent publications on the relationship of mtDNA point mutations to mitochondrial diseases, which unveil the importance of development of molecular diagnosis. The presence of A3243G, T3271C, T3291C, C3256T, A8344G, G8356A, A3260G, СЗЗОЗТ, and A4300Gmutations in mtDNA may suggest that there are multiorgan dysfunctions and multisystem disorders, the clinical signs and symptoms of which can vary with time, which emphasizes the importance of comprehensive genetic studies if the mitochondrial disease is assumed to be clinical.

  13. Actionable mutations in canine hemangiosarcoma.

    Directory of Open Access Journals (Sweden)

    Guannan Wang

    Full Text Available Angiosarcomas (AS are rare in humans, but they are a deadly subtype of soft tissue sarcoma. Discovery sequencing in AS, especially the visceral form, is hampered by the rarity of cases. Most diagnostic material exists as archival formalin fixed, paraffin embedded tissue which serves as a poor source of high quality DNA for genome-wide sequencing. We approached this problem through comparative genomics. We hypothesized that exome sequencing a histologically similar tumor, hemangiosarcoma (HSA, that occurs in approximately 50,000 dogs per year, may lead to the identification of potential oncogenic drivers and druggable targets that could also occur in angiosarcoma.Splenic hemangiosarcomas are common in dogs, which allowed us to collect a cohort of archived matched tumor and normal tissue samples suitable for whole exome sequencing. Mapping of the reads to the latest canine reference genome (Canfam3 demonstrated that >99% of the targeted exomal regions were covered, with >80% at 20X coverage and >90% at 10X coverage.Sequence analysis of 20 samples identified somatic mutations in PIK3CA, TP53, PTEN, and PLCG1, all of which correspond to well-known tumor drivers in human cancer, in more than half of the cases. In one case, we identified a mutation in PLCG1 identical to a mutation observed previously in this gene in human visceral AS. Activating PIK3CA mutations present novel therapeutic targets, and clinical trials of targeted inhibitors are underway in human cancers. Our results lay a foundation for similar clinical trials in canine HSA, enabling a precision medicine approach to this disease.

  14. Actionable mutations in canine hemangiosarcoma. (United States)

    Wang, Guannan; Wu, Ming; Maloneyhuss, Martha A; Wojcik, John; Durham, Amy C; Mason, Nicola J; Roth, David B


    Angiosarcomas (AS) are rare in humans, but they are a deadly subtype of soft tissue sarcoma. Discovery sequencing in AS, especially the visceral form, is hampered by the rarity of cases. Most diagnostic material exists as archival formalin fixed, paraffin embedded tissue which serves as a poor source of high quality DNA for genome-wide sequencing. We approached this problem through comparative genomics. We hypothesized that exome sequencing a histologically similar tumor, hemangiosarcoma (HSA), that occurs in approximately 50,000 dogs per year, may lead to the identification of potential oncogenic drivers and druggable targets that could also occur in angiosarcoma. Splenic hemangiosarcomas are common in dogs, which allowed us to collect a cohort of archived matched tumor and normal tissue samples suitable for whole exome sequencing. Mapping of the reads to the latest canine reference genome (Canfam3) demonstrated that >99% of the targeted exomal regions were covered, with >80% at 20X coverage and >90% at 10X coverage. Sequence analysis of 20 samples identified somatic mutations in PIK3CA, TP53, PTEN, and PLCG1, all of which correspond to well-known tumor drivers in human cancer, in more than half of the cases. In one case, we identified a mutation in PLCG1 identical to a mutation observed previously in this gene in human visceral AS. Activating PIK3CA mutations present novel therapeutic targets, and clinical trials of targeted inhibitors are underway in human cancers. Our results lay a foundation for similar clinical trials in canine HSA, enabling a precision medicine approach to this disease.

  15. LHON: Mitochondrial Mutations and More. (United States)

    Kirches, E


    Leber's hereditary optic neuropathy (LHON) is a mitochondrial disorder leading to severe visual impairment or even blindness by death of retinal ganglion cells (RGCs). The primary cause of the disease is usually a mutation of the mitochondrial genome (mtDNA) causing a single amino acid exchange in one of the mtDNA-encoded subunits of NADH:ubiquinone oxidoreductase, the first complex of the electron transport chain. It was thus obvious to accuse neuronal energy depletion as the most probable mediator of neuronal death. The group of Valerio Carelli and other authors have nicely shown that energy depletion shapes the cell fate in a LHON cybrid cell model. However, the cybrids used were osteosarcoma cells, which do not fully model neuronal energy metabolism. Although complex I mutations may cause oxidative stress, a potential pathogenetic role of the latter was less taken into focus. The hypothesis of bioenergetic failure does not provide a simple explanation for the relatively late disease onset and for the incomplete penetrance, which differs remarkably between genders. It is assumed that other genetic and environmental factors are needed in addition to the 'primary LHON mutations' to elicit RGC death. Relevant nuclear modifier genes have not been identified so far. The review discusses the unresolved problems of a pathogenetic hypothesis based on ATP decline and/or ROS-induced apoptosis in RGCs.

  16. Mutation Frequency and Spectrum of Mutations Vary at Different Chromosomal Positions of Pseudomonas putida (United States)

    Juurik, Triinu; Ilves, Heili; Teras, Riho; Ilmjärv, Tanel; Tavita, Kairi; Ukkivi, Kärt; Teppo, Annika; Mikkel, Katren; Kivisaar, Maia


    It is still an open question whether mutation rate can vary across the bacterial chromosome. In this study, the occurrence of mutations within the same mutational target sequences at different chromosomal locations of Pseudomonas putida was monitored. For that purpose we constructed two mutation detection systems, one for monitoring the occurrence of a broad spectrum of mutations and transposition of IS element IS1411 inactivating LacI repressor, and another for detecting 1-bp deletions. Our results revealed that both the mutation frequency and the spectrum of mutations vary at different chromosomal positions. We observed higher mutation frequencies when the direction of transcription of the mutational target gene was opposite to the direction of replisome movement in the chromosome and vice versa, lower mutation frequency was accompanied with co-directional transcription and replication. Additionally, asymmetry of frameshift mutagenesis at homopolymeric and repetitive sequences during the leading and lagging-strand replication was found. The transposition frequency of IS1411 was also affected by the chromosomal location of the target site, which implies that regional differences in chromosomal topology may influence transposition of this mobile element. The occurrence of mutations in the P. putida chromosome was investigated both in growing and in stationary-phase bacteria. We found that the appearance of certain mutational hot spots is strongly affected by the chromosomal location of the mutational target sequence especially in growing bacteria. Also, artificial increasing transcription of the mutational target gene elevated the frequency of mutations in growing bacteria. PMID:23119042

  17. EGFR mutation frequency and effectiveness of erlotinib

    DEFF Research Database (Denmark)

    Weber, Britta; Hager, Henrik; Sorensen, Boe S


    OBJECTIVES: In 2008, we initiated a prospective study to explore the frequency and predictive value of epidermal growth factor receptor (EGFR) mutations in an unselected population of Danish patients with non-small cell lung cancer offered treatment with erlotinib, mainly in second-line. MATERIALS...... AND METHODS: Four hundred and eighty eight patients with advanced NSCLC were included. The mutation status was assessed using the cobas EGFR Mutation Test. Erlotinib was administrated (150 mg/d) until disease progression or unacceptable toxicities occurred. The primary endpoint was progression-free survival....... Secondary endpoints were overall survival and response. RESULTS: Biopsies were retrieved from 467 patients, and mutation results obtained for 462. We identified 57 (12%) patients with EGFR mutations: 33 exon 19 deletions, 13 exon 21 mutations, 5 exon 18 mutations, 3 exon 20 insertions, 1 exon 20 point...

  18. Mutation induction by ion beams in plants

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment


    The effect of ion beams such as C, He, and Ne ions was investigated on the mutation induction in plants with the expectation that ion beams of high linear energy transfer (LET) can frequently produce large DNA alternation such as inversion, translocation and large deletion rather than point mutation. Mutation frequency was investigated using Arabidopsis visible phenotype loci and was 8 to 33 fold higher for 220 MeV carbon ions than for electrons. Mutation spectrum was investigated on the flower color of chrysanthemum cv to find that flower mutants induced by ion beams show complex and stripe types rather than single color. Polymerase chain reaction analysis was performed to investigate DNA alteration of mutations. In conclusion, the characteristics of ion beams for the mutation induction are 1) high frequency, 2) broad mutation spectrum, and 3) novel mutants. (S. Ohno)

  19. Rare and unexpected beta thalassemic mutations in Qazvin ...

    African Journals Online (AJOL)



    Jan 4, 2010 ... About 13 beta-globin mutations encompass 70 - 90% of mutation spectrum in Iran. These mutations are called common beta-globin mutations. The rest are rare or unknown mutations. The objective of this study was to identify and describe rare or unknown beta-globin mutations in Qazvin province. EDTA-.

  20. Rare and unexpected beta thalassemic mutations in Qazvin ...

    African Journals Online (AJOL)

    About 13 beta-globin mutations encompass 70 - 90% of mutation spectrum in Iran. These mutations are called common beta-globin mutations. The rest are rare or unknown mutations. The objective of this study was to identify and describe rare or unknown beta-globin mutations in Qazvin province. EDTAcontaining venous ...

  1. Oncogene mutational profile in nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Zhang ZC


    Full Text Available Zi-Chen Zhang,1,* Sha Fu,1,* Fang Wang,1 Hai-Yun Wang,1 Yi-Xin Zeng,2 Jian-Yong Shao11Department of Molecular Diagnostics, 2Department of Experimental Research, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, People's Republic of China *These authors contributed equally to this work Abstract: Nasopharyngeal carcinoma (NPC is a common tumor in Southern China, but the oncogene mutational status of NPC patients has not been clarified. Using time-of-flight mass spectrometry, 238 mutation hotspots in 19 oncogenes were examined in 123 NPC patients. The relationships between mutational status and clinical data were assessed with a χ2 or Fisher's exact test. Survival analysis was performed using the Kaplan–Meier method with the log-rank test. In 123 patients, 21 (17.1% NPC tumors were positive for mutations in eight oncogenes: six patients had PIK3CA mutations (4.9%, five NRAS mutations (4.1%, four KIT mutations (3.3%, two PDGFRA mutations (1.6%, two ABL mutations (1.6%, and one with simultaneous mutations in HRAS, EGFR, and BRAF (1%. Patients with mutations were more likely to relapse or develop metastasis than those with wild-type alleles (P=0.019. No differences or correlations were found in other clinical characteristics or in patient survival. No mutations were detected in oncogenes AKT1, AKT2, CDK, ERBB2, FGFR1, FGFR3, FLT3, JAK2, KRAS, MET, and RET. These results demonstrate an association between NPC and mutations in NRAS, KIT, PIK3CA, PDGFRA, and ABL, which are associated with patient relapse and metastasis. Keywords: NPC, oncogene, mutation

  2. [Effect of Point Mutations in the Polymerase Genes of the Influenza A/PR/8/34 (H1N1) Virus on the Immune Response in a Mouse Model]. (United States)

    Kuznetsova, S A; Isakova-Sivak, I N; Kuznetcova, V A; Petukhova, G D; Losev, I V; Donina, S A; Rudenko, L G; Naikhin, A N


    The vaccine strains for live attenuated influenza vaccines (LAIVs) have cold-adapted, temperature-sensitive, and attenuated phenotypes, which are guaranteed by the presence of specific mutations from the master donor virus in their internal genes. In this study, we used mutant viruses of the pathogenic A/Puerto Rico/8/34 (H1N1) that contained ts-mutations in PB1 (K265N, V591I), PB2 (V478L), and PA (L28P, V341L) genes along and/or in different combinations to evaluate the impact of these mutations in the immune responses. Sequential addition of tested mutations resulted in the stepwise decrease in virus-specific serum and, to a lesser extent, mucosal antibody levels. We demonstrated strong positive correlation between virus attenuation (virus titer in lung) and antibody titers. The ts-mutations in PB1, PB2, and PA genes are mostly involved in the modulation of the humoral immunity, but also have a moderate effect on the cellular adaptive immune response.

  3. Mutation analysis of Swedish haemophilia B families - high frequency of unique mutations. (United States)

    Mårtensson, A; Letelier, A; Halldén, C; Ljung, R


    Haemophilia B is caused by a heterogeneous spectrum of mutations. Mutation characterization is important in genetic counselling, prenatal diagnosis and to predict risk of inhibitor development. To study the mutation spectrum, frequency of unique recurrent mutations, genotype-phenotype association and inhibitor development in a population-based study of the complete Swedish haemophilia B population. The study included, facilitated by centralized DNA diagnostics, the complete registered Swedish haemophilia B population (113 families: 47 severe, 22 moderate and 44 mild), each represented by a single patient. Mutation characterization was performed by conventional sequencing of all exons and haplotyping by genotyping of single nucleotide variants and microsatellites. A mutation was found in every family: eight had large deletions, three had small deletions (mutations were found and were predicted to be deleterious. Sixteen mutations (one total gene deletion, 14 substitutions and one acceptor splice site) were present in more than one family. Of the single nucleotide mutations (37/102), 36% arose at CpG sites. Haplotyping of families with identical mutations and present analyses showed that the frequency of unique mutations was at least 65%. Inhibitors developed in 9/47 (19%) patients with severe haemophilia B. The spectrum of haemophilia B mutations reveals at least 65% of the families carry a unique mutation, but with more inhibitor patients than reported internationally, probably as a result of many 'null' mutations. © 2015 John Wiley & Sons Ltd.

  4. Comparison of uncommon EGFR exon 21 L858R compound mutations with single mutation. (United States)

    Peng, Liang; Song, Zhigang; Jiao, Shunchang


    Non-small-cell lung cancer with epidermal growth factor receptor (EGFR) mutation is sensitive to EGFR tyrosine kinase inhibitors (TKIs). But little is known about the response to EGFR TKIs and the prognostic role of compound mutations. This study compared the uncommon EGFR exon 21 L858R compound mutations with single mutation to characterize EGFR compound mutations and investigated their response to EGFR TKI treatment. We retrospectively screened 799 non-small-cell lung cancer patients from August 1, 2009 to June 1, 2012 by EGFR mutation testing. EGFR mutations were detected in 443 patients, with 22 (4.97%) compound mutations. Subsequently, six patients with EGFR exon 21 L858R compound mutations and 18 paired patients with single L858R mutation were well characterized. Finally, we also analyzed the EGFR TKI treatment response and patients' outcomes of compound or single L858R mutations. There was no differential treatment effect on the disease control rate and objective response rate between the L858R compound mutations and single mutation groups. No significant difference in overall survival or progression-free survival of these two groups was found by log-rank test. In conclusion, we demonstrated that no significant difference was detected in the response to EGFR TKIs and patients' outcomes in the compound and single mutation groups.

  5. Cataract mutations and lens development. (United States)

    Graw, J


    The lens plays an essential role for proper eye development. Mouse mutants affecting lens development are excellent models for corresponding human disorders. Moreover, using mutations in particular genes the process of eye and lens development can be dissected into distinct steps. Therefore, three mouse mutants will be described in detail and discussed affecting three essential stages: formation of the lens vesicle, initiation of secondary lens fiber cell formation, and terminal differentiation of the secondary fiber cells. The mutant aphakia (ak) has been characterized by bilaterally apakic eyes [Varnum and Stevens (1968) J. Hered. 59, 147-150], and the corresponding gene was mapped to chromosome 19 [Varnum and Stevens (1975) Mouse News Letters 53, 35]. Recent investigations in our laboratory refined the linkage 0.6 +/- 0.3 N cm proximal to the microsatellite marker D19Mit10. The linked gene Pax2, responsible for proper development of the posterior part of the eye and the optic nerve, was excluded as candidate gene by sequence analysis. Histological analysis of the homozygous ak mutants revealed a persisting lens stalk and subsequently the formation of lens rudiments. The lens defects led to irregular iris development and retinal folding. Congenital aphakia is known as a rare human anomaly. Besides a corneal dystrophy (CDTB), no corresponding disease is localized at the homologous region of human chromosome 10q23. The Cat3 mutations are characterized by vacuolated lenses caused by alterations in the beginning of secondary lens fiber cell differentiation at embryonic day 12.5. Secondary malformations develop at the cornea and the iris, but the retina remains unaffected. Two mutant alleles of the Cat3 locus have been mapped to mouse chromosome 10 very close to the microsatellite markers D10Mit41 and D10Mit95 (less than 0.3 cM). Since Cat3 is mapped to a position, which is homologous to human chromosome 12q21-24, the disorder cornea plana congenita can be considered

  6. Mutations in yeast calmodulin cause defects in spindle pole body functions and nuclear integrity. (United States)

    Sun, G H; Hirata, A; Ohya, Y; Anraku, Y


    Yeast calmodulin (CaM) is required for the progression of nuclear division (Ohya, Y. and Y. Anraku. 1989. Curr. Genet. 15:113-120), although the precise mechanism and physiological role of CaM in this process are unclear. In this paper we have characterized the phenotype caused by a temperature-sensitive lethal mutation (cmdl-101) in the yeast CaM. The cmdl-101 mutation expresses a carboxyl-terminal half of the yeast CaM (Met72-Cys147) under the control of an inducible GAL1 promoter. Incubation of the cmdl-101 cells at a nonpermissive temperature causes a severe defect in chromosome segregation. The rate of chromosome loss in the cmdl-101 mutant is higher than wild-type cell even at permissive temperature. The primary visible defect observed by immunofluorescence and electron microscopic analyses is that the organization of spindle microtubules is abnormal in the cmdl-101 cells grown at nonpermissive temperature. Majority of budded cells arrested at the high temperature contain only one spindle pole body (SPB), which forms monopolar spindle, whereas the budded cells of the same strain incubated at permissive temperature all contain two SPBs. Using the freeze-substituted fixation method, we found that the integrity of the nuclear morphology of the cmdl-101 mutant cell is significantly disturbed. The nucleus in wild-type cells is round with smooth contours of nuclear envelope. However, the nuclear envelope in the mutant cells appears to be very flexible and forms irregular projections and invaginations that are never seen in wild-type cells. The deformation of the nuclear becomes much more severe as the incubation at nonpermissive temperature continues. The single SPB frequently localizes on the projections or the invaginations of the nuclear envelope. These observations suggest that CaM is required for the functions of SPB and spindle, and the integrity of nucleus.

  7. Impacts of mutation effects and population size on mutation rate in asexual populations: a simulation study

    Directory of Open Access Journals (Sweden)

    Huang Zhuoran


    Full Text Available Abstract Background In any natural population, mutation is the primary source of genetic variation required for evolutionary novelty and adaptation. Nevertheless, most mutations, especially those with phenotypic effects, are harmful and are consequently removed by natural selection. For this reason, under natural selection, an organism will evolve to a lower mutation rate. Overall, the action of natural selection on mutation rate is related to population size and mutation effects. Although theoretical work has intensively investigated the relationship between natural selection and mutation rate, most of these studies have focused on individual competition within a population, rather than on competition among populations. The aim of the present study was to use computer simulations to investigate how natural selection adjusts mutation rate among asexually reproducing subpopulations with different mutation rates. Results The competition results for the different subpopulations showed that a population could evolve to an "optimum" mutation rate during long-term evolution, and that this rate was modulated by both population size and mutation effects. A larger population could evolve to a higher optimum mutation rate than could a smaller population. The optimum mutation rate depended on both the fraction and the effects of beneficial mutations, rather than on the effects of deleterious ones. The optimum mutation rate increased with either the fraction or the effects of beneficial mutations. When strongly favored mutations appeared, the optimum mutation rate was elevated to a much higher level. The competition time among the subpopulations also substantially shortened. Conclusions Competition at the population level revealed that the evolution of the mutation rate in asexual populations was determined by both population size and mutation effects. The most striking finding was that beneficial mutations, rather than deleterious mutations, were the

  8. Driven by Mutations: The Predictive Value of Mutation Subtype in EGFR-Mutated Non-Small Cell Lung Cancer. (United States)

    Castellanos, Emily; Feld, Emily; Horn, Leora


    EGFR-mutated NSCLC is a genetically heterogeneous disease that includes more than 200 distinct mutations. The implications of mutational subtype for both prognostic and predictive value are being increasingly understood. Although the most common EGFR mutations-exon 19 deletions or L858R mutations-predict sensitivity to EGFR tyrosine kinase inhibitors (TKIs), it is now being recognized that outcomes may be improved in patients with exon 19 deletions. Additionally, 10% of patients will have an uncommon EGFR mutation, and response to EGFR TKI therapy is highly variable depending on the mutation. Given the growing recognition of the genetic and clinical variation seen in this disease, the development of comprehensive bioinformatics-driven tools to both analyze response in uncommon mutation subtypes and inform clinical decision making will be increasingly important. Clinical trials of novel EGFR TKIs should prospectively account for the presence of uncommon mutation subtypes in study design. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  9. Temperature-dependent sex-reversal by a transformer-2 gene-edited mutation in the spotted wing drosophila, Drosophila suzukii. (United States)

    Li, Jianwei; Handler, Alfred M


    Female to male sex reversal was achieved in an emerging agricultural insect pest, Drosophila suzukii, by creating a temperature-sensitive point mutation in the sex-determination gene, transformer-2 (tra-2), using CRISPR/Cas9 (clustered regularly interspaced palindromic repeats/CRISPR-associated) homology-directed repair gene-editing. Ds-tra-2 ts2 mutants developed as normal fertile XX and XY adults at permissive temperatures below 20 °C, but at higher restrictive temperatures (26 to 29 °C) chromosomal XX females developed as sterile intersexuals with a predominant male phenotype, while XY males developed with normal morphology, but were sterile. The temperature-dependent function of the Ds-TRA-2 ts2 protein was also evident by the up- and down-regulation of female-specific Ds-Yolk protein 1 (Ds-Yp1) gene expression by temperature shifts during adulthood. This study confirmed the temperature-dependent function of a gene-edited mutation and provides a new method for the more general creation of conditional mutations for functional genomic analysis in insects, and other organisms. Furthermore, it provides a temperature-dependent system for creating sterile male populations useful for enhancing the efficacy of biologically-based programs, such as the sterile insect technique (SIT), to control D. suzukii and other insect pest species of agricultural and medical importance.

  10. Somatic mutations in aging, cancer and neurodegeneration. (United States)

    Kennedy, Scott R; Loeb, Lawrence A; Herr, Alan J


    The somatic mutation theory of aging posits that the accumulation of mutations in the genetic material of somatic cells as a function of time results in a decrease in cellular function. In particular, the accumulation of random mutations may inactivate genes that are important for the functioning of the somatic cells of various organ systems of the adult, result in a decrease in organ function. When the organ function decreases below a critical level, death occurs. A significant amount of research has shown that somatic mutations play an important role in aging and a number of age related pathologies. In this review, we explore evidence for increases in somatic nuclear mutation burden with age and the consequences for aging, cancer, and neurodegeneration. We then review evidence for increases in mitochondrial mutation burden and the consequences for dysfunction in the disease processes. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Is The Ribosome Targeted By Adaptive Mutations

    DEFF Research Database (Denmark)

    Jimenez Fernandez, Alicia; Molin, Søren; Johansen, Helle Krogh


    degree of evolutionary conservation of the cellular MMSM tend to support this view. However, under certain selective conditions the machinery itself may be targeted by adaptive mutations, which result in fitness-increasing phenotypic changes. Here we investigate and characterize the role of ribosomal...... mutations in adaptive evolution. Methods: Several mutations in ribosomal genes have been identified in the genome analysis of nearly 700 Pseudomonas aeruginosa isolates from infected cystic fibrosis patients. Among these mutations we have repeatedly identified insertions, deletions and substitutions...... in specific ribosomal genes. The bacterial phenotypes of the mutated strains will be investigated. Results: Preliminary assays show that mutant strains have reduced growth rate and an altered antibiotic resistance pattern. The selection for mutations in ribosomal protein genes is partly explainable...

  12. Mitochondrial mutations drive prostate cancer aggression


    Hopkins, Julia F.; Sabelnykova, Veronica Y; Weischenfeldt, Joachim; Simon, Ronald; Aguiar, Jennifer A.; Alkallas, Rached; Heisler, Lawrence E.; Zhang, Junyan; Watson, John D.; Chua, Melvin L. K.; Fraser, Michael; Favero, Francesco; Lawerenz, Chris; Plass, Christoph; Sauter, Guido


    Nuclear mutations are well known to drive tumor incidence, aggression and response to therapy. By contrast, the frequency and roles of mutations in the maternally inherited mitochondrial genome are poorly understood. Here we sequence the mitochondrial genomes of 384 localized prostate cancer patients, and identify a median of one mitochondrial single-nucleotide variant (mtSNV) per patient. Some of these mtSNVs occur in recurrent mutational hotspots and associate with aggressive disease. Young...

  13. A new mutation in blau syndrome. (United States)

    Zeybek, Cengiz; Basbozkurt, Gokalp; Gul, Davut; Demirkaya, Erkan; Gok, Faysal


    Blau syndrome is a rare, autosomal dominant, granulomatous autoinflammatory disease. The classic triad of the disease includes recurrent uveitis, granulomatous dermatitis, and symmetrical arthritis. Blau syndrome is related to mutations located at the 16q12.2-13 gene locus. To date, 11 NOD2 gene mutations causing Blau syndrome have been described. Here, we describe a 5-year-old male patient who presented with Blau syndrome associated with a novel sporadic gene mutation that has not been reported previously.

  14. The Mutational Robustness of Influenza A Virus.

    Directory of Open Access Journals (Sweden)

    Elisa Visher


    Full Text Available A virus' mutational robustness is described in terms of the strength and distribution of the mutational fitness effects, or MFE. The distribution of MFE is central to many questions in evolutionary theory and is a key parameter in models of molecular evolution. Here we define the mutational fitness effects in influenza A virus by generating 128 viruses, each with a single nucleotide mutation. In contrast to mutational scanning approaches, this strategy allowed us to unambiguously assign fitness values to individual mutations. The presence of each desired mutation and the absence of additional mutations were verified by next generation sequencing of each stock. A mutation was considered lethal only after we failed to rescue virus in three independent transfections. We measured the fitness of each viable mutant relative to the wild type by quantitative RT-PCR following direct competition on A549 cells. We found that 31.6% of the mutations in the genome-wide dataset were lethal and that the lethal fraction did not differ appreciably between the HA- and NA-encoding segments and the rest of the genome. Of the viable mutants, the fitness mean and standard deviation were 0.80 and 0.22 in the genome-wide dataset and best modeled as a beta distribution. The fitness impact of mutation was marginally lower in the segments coding for HA and NA (0.88 ± 0.16 than in the other 6 segments (0.78 ± 0.24, and their respective beta distributions had slightly different shape parameters. The results for influenza A virus are remarkably similar to our own analysis of CirSeq-derived fitness values from poliovirus and previously published data from other small, single stranded DNA and RNA viruses. These data suggest that genome size, and not nucleic acid type or mode of replication, is the main determinant of viral mutational fitness effects.

  15. Prevalent mutations in prostate cancer. (United States)

    Dong, Jin-Tang


    Quantitative and structural genetic alterations cause the development and progression of prostate cancer. A number of genes have been implicated in prostate cancer by genetic alterations and functional consequences of the genetic alterations. These include the ELAC2 (HPC2), MSR1, and RNASEL (HPC1) genes that have germline mutations in familial prostate cancer; AR, ATBF1, EPHB2 (ERK), KLF6, mitochondria DNA, p53, PTEN, and RAS that have somatic mutations in sporadic prostate cancer; AR, BRCA1, BRCA2, CHEK2 (RAD53), CYP17, CYP1B1, CYP3A4, GSTM1, GSTP1, GSTT1, PON1, SRD5A2, and VDR that have germline genetic variants associated with either hereditary and/or sporadic prostate cancer; and ANXA7 (ANX7), KLF5, NKX3-1 (NKX3.1), CDKN1B (p27), and MYC that have genomic copy number changes affecting gene function. More genes relevant to prostate cancer remain to be identified in each of these gene groups. For the genes that have been identified, most need additional genetic, functional, and/or biochemical examination. Identification and characterization of these genes will be a key step for improving the detection and treatment of prostate cancer. (c) 2005 Wiley-Liss, Inc.

  16. Mutational analysis of Bloom helicase. (United States)

    Xi, Xu Guang


    DNA helicases are biomolecular motors that convert the chemical energy derived from the hydrolysis of nucleotide triphosphate (usually ATP) into mechanical energy to unwind double-stranded DNA. The unwinding of double-stranded DNA is an essential process for DNA replication, repair, recombination, and transcription. Mutations in human RecQ helicases result in inherent human disease including Bloom's syndrome, Werner's syndrome, and Rothmund-Thomson syndrome. Bloom's syndrome (BS) is a rare human autosomal recessive disorder characterized by a strong predisposition to a wide range of cancers commonly affecting the general population. In order to understand the molecular basis of BS pathology and the mechanism underlying the function of Bloom helicase, we have analyzed BS-causing missense mutations by a combination of structural modeling, site-directed mutagenesis, and biochemical and biophysical approaches. Here, we describe the methods and protocols for measuring ATPase, ATP and DNA binding, DNA strand annealing, and DNA unwinding activities of Bloom protein and its mutant variants. These approaches should be applicable and useful for studying other helicases.

  17. Copy number variation and mutation (United States)

    Clark, Brian; Weidner, Jacob; Wabick, Kevin


    Until very recently, the standard model of DNA included two genes for each trait. This dated model has given way to a model that includes copies of some genes well in excess of the canonical two. Copy number variations in the human genome play critical roles in causing or aggravating a number of syndromes and diseases while providing increased resistance to others. We explore the role of mutation, crossover, inversion, and reproduction in determining copy number variations in a numerical simulation of a population. The numerical model consists of a population of individuals, where each individual is represented by a single strand of DNA with the same number of genes. Each gene is initially assigned to one of two traits. Fitness of the individual is determined by the two most fit genes for trait one, and trait two genetic material is treated as a reservoir of junk DNA. After a sufficient number of generations, during which the genetic distribution is allowed to reach a steady-state, the mean numberof genes per trait and the copy number variation are recorded. Here, we focus on the role of mutation and compare simulation results to theory.

  18. Mutational remodeling of enzyme specificity. (United States)

    Bone, R; Agard, D A


    With the advent of genetic engineering techniques has come the ability to modify proteins as desired. Given this stunning capability, the question remains what residues should be altered, and how should they be changed to achieve a particular specificity pattern. The goals of such modifications are likely to fall into either of two categories: probing the function of a protein or attempting to alter its properties. In either case, our understanding of the consequences of a mutation, as ascertained by our ability to predict the results, is currently quite limited. The problem is extraordinarily complex; our understanding of how to calculate the energetics involved is still incomplete, and we are just beginning to accumulate experimental data which may help guide us. On the positive side, theoretical methods are now being developed and refined that should prove useful in the drive to engineer enzyme specificity. What may be most important at this juncture is to expand the experimental database interrelating sequence, function, and structure. That is, there should be a concerted effort to combine functional analysis of mutant proteins with structural analysis. Only from this combined examination of the effects of mutations can sufficient data be accumulated to test and improve both qualitative and quantitative approaches or methods for remodeling enzyme specificity.

  19. A frequent splicing mutation and novel missense mutations color the updated mutational spectrum of classic galactosemia in Portugal. (United States)

    Coelho, Ana I; Ramos, Ruben; Gaspar, Ana; Costa, Cláudia; Oliveira, Anabela; Diogo, Luísa; Garcia, Paula; Paiva, Sandra; Martins, Esmeralda; Teles, Elisa Leão; Rodrigues, Esmeralda; Cardoso, M Teresa; Ferreira, Elena; Sequeira, Sílvia; Leite, Margarida; Silva, Maria João; de Almeida, Isabel Tavares; Vicente, João B; Rivera, Isabel


    Classic galactosemia is an autosomal recessive disorder caused by deficient galactose-1-phosphate uridylyltransferase (GALT) activity. Patients develop symptoms in the neonatal period, which can be ameliorated by dietary restriction of galactose. Many patients develop long-term complications, with a broad range of clinical symptoms whose pathophysiology is poorly understood. The high allelic heterogeneity of GALT gene that characterizes this disorder is thought to play a determinant role in biochemical and clinical phenotypes. We aimed to characterize the mutational spectrum of GALT deficiency in Portugal and to assess potential genotype-phenotype correlations. Direct sequencing of the GALT gene and in silico analyses were employed to evaluate the impact of uncharacterized mutations upon GALT functionality. Molecular characterization of 42 galactosemic Portuguese patients revealed a mutational spectrum comprising 14 nucleotide substitutions: ten missense, two nonsense and two putative splicing mutations. Sixteen different genotypic combinations were detected, half of the patients being p.Q188R homozygotes. Notably, the second most frequent variation is a splicing mutation. In silico predictions complemented by a close-up on the mutations in the protein structure suggest that uncharacterized missense mutations have cumulative point effects on protein stability, oligomeric state, or substrate binding. One splicing mutation is predicted to cause an alternative splicing event. This study reinforces the difficulty in establishing a genotype-phenotype correlation in classic galactosemia, a monogenic disease whose complex pathogenesis and clinical features emphasize the need to expand the knowledge on this "cloudy" disorder.

  20. APC mutation spectrum of Norwegian familial adenomatous polyposis families: high ratio of novel mutations. (United States)

    Andresen, Per Arne; Heimdal, Ketil; Aaberg, Kristin; Eklo, Katrine; Eklo, Kristin; Ariansen, Sarah; Silye, Alexandra; Fausa, Olav; Aabakken, Lars; Aretz, Stefan; Eide, Tor J; Gedde-Dahl, Tobias


    Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited disease caused by mutations in the adenomatous polyposis coli (APC) gene. Massive formation of colorectal adenomas, of which some will inevitably develop into adenocarcinomas, is the hallmark of the disease. Characterization of causative APC mutations allows presymptomatic diagnosis, close follow-up and prophylactic intervention in families. To date more than 900 different germline mutations have been characterized worldwide demonstrating allelic heterogeneity. The germline mutation spectrum of APC identified in 69 apparently unrelated Norwegian FAP families are presented and discussed with reference to clinical phenotype and novel mutation rate. Different methods have been used over the years. However, all mutations were confirmed detectable by an implemented denaturing high-performance liquid chromatography screening approach. Multiplex ligation-dependent probe amplification analysis was employed for potential gross rearrangements. Fifty-three distinctive mutations were detected, of which 22 have been detected in Norway exclusively. Except for two major deletion mutations encompassing the entire APC, all mutations resulted in premature truncation of translation caused by non-sense (31%) or change in reading frame (69%). A high ratio of novel APC mutations continues to contribute to APC mutation heterogeneity causing FAP. This is the first comprehensive report of APC germline mutation spectrum in Norway.

  1. FKRP mutations, including a founder mutation, cause phenotype variability in Chinese patients with dystroglycanopathies. (United States)

    Fu, Xiaona; Yang, Haipo; Wei, Cuijie; Jiao, Hui; Wang, Shuo; Yang, Yanling; Han, Chunxi; Wu, Xiru; Xiong, Hui


    Mutations in the fukutin-related protein (FKRP) gene have been associated with dystroglycanopathies, which are common in Europe but rare in Asia. Our study aimed to retrospectively analyze and characterize the clinical, myopathological and genetic features of 12 Chinese patients with FKRP mutations. Three patients were diagnosed with congenital muscular dystrophy type 1C (MDC1C) and nine patients were diagnosed with limb girdle muscular dystrophy type 2I (LGMD2I). Three muscle biopsy specimens had dystrophic changes and reduced glycosylated α-dystroglycan staining, and two showed reduced expression of laminin α2. Two known and 13 novel mutations were identified in our single center cohort. Interestingly, the c.545A>G mutation was found in eight of the nine LGMD2I patients as a founder mutation and this founder mutation in Chinese patients differs from the one seen in European patients. Moreover, patients homozygous for the c.545A>G mutation were clinically asymptomatic, a less severe phenotype than in compound heterozygous patients with the c.545A>G mutation. The 13 novel mutations of FKRP significantly expanded the mutation spectrum of MDC1C and LGMD2I, and the different founder mutations indicate the ethnic difference in FKRP mutations.

  2. Studies of human mutation rates

    Energy Technology Data Exchange (ETDEWEB)

    Neel, J.V.


    November 1989, marked the beginning of a new three-year cycle of DOE grant support, in connection with which the program underwent a major reorganization. This document presents the progress on the three objectives of the present program which are: to isolate by the technique of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), proteins of special interest because of the relative mutability of the corresponding gene, establish the identity of the protein, and, for selected proteins, move to a characterization of the corresponding gene; to develop a more efficient approach, based on 2-D PAGE, for the detection of variants in DNA, with special reference to the identification of mutations in the parents of the individual whose DNA is being examined; and, to continue an effective interface with the genetic studies on the children of atomic bomb survivors in Japan, with reference to both the planning and implementation of new studies at the molecular level.

  3. 'A' by Aspergillus terreus through mutation

    African Journals Online (AJOL)

    The highest drug yielding isolate FCBP-58 was subjected to both physical and chemical mutation to increase the biosynthetic capabilities of Cyclosporin 'A'. In this study, mutation was carried out by ultraviolet radiation (254 nm) and alkylating agent ethylmethane sulphonate (EMS). UV 5 min time treatment was proved to be ...

  4. De novo mutations in human genetic disease

    NARCIS (Netherlands)

    Veltman, J.A.; Brunner, H.G.


    New mutations have long been known to cause genetic disease, but their true contribution to the disease burden can only now be determined using family-based whole-genome or whole-exome sequencing approaches. In this Review we discuss recent findings suggesting that de novo mutations play a prominent

  5. The unfolding clinical spectrum of POLG mutations

    NARCIS (Netherlands)

    Blok, M. J.; van den Bosch, B. J.; Jongen, E.; Hendrickx, A.; de Die-Smulders, C. E.; Hoogendijk, J. E.; Brusse, E.; de Visser, M.; Poll-The, B. T.; Bierau, J.; de Coo, I. F.; Smeets, H. J.


    BACKGROUND: Mutations in the DNA polymerase-gamma (POLG) gene are a major cause of clinically heterogeneous mitochondrial diseases, associated with mtDNA depletion and multiple deletions. OBJECTIVE: To determine the spectrum of POLG mutations in our Dutch patient cohort, to evaluate the

  6. The unfolding clinical spectrum of POLG mutations

    NARCIS (Netherlands)

    Blok, M.J.; Bosch, B.J.; Jongen, E.; Hendrickx, A.; de Die-Smulders, C.E.; Hoogendijk, J.E.; Brusse, E.; de Visser, M.; Poll-The, B.T.; Bierau, J.; de Coo, I.F.; Smeets, H.J.


    Background: Mutations in the DNA polymerase-gamma (POLG) gene are a major cause of clinically heterogeneous mitochondrial diseases, associated with mtDNA depletion and multiple deletions. Objective: To determine the spectrum of POLG mutations in our Dutch patient cohort, to evaluate the

  7. The mutation rate to Huntington's chorea (United States)

    Shaw, Michael; Caro, Adrian


    The problems of estimating the mutation rate to Huntington's chorea, or the proportion of new mutants among all sufferers, are discussed. The available survey data are reviewed. The prevalence of sporadic phenotypes, which include new mutations, is probably less than 2·5%. New mutants probably make up around 0·1% or less of all sufferers. PMID:6213773

  8. Tuberous Sclerosis Complex: mutations, functions and phenotypes

    NARCIS (Netherlands)

    O. Sancak (Ozgur)


    textabstractTuberous sclerosis complex (TSC) is an autosomal dominant disorder characterised by the development of hamartomas in multiple organs and tissues. TSC is caused by mutations in either the TSC1 or TSC2 gene. We searched for mutations in both genes in a cohort of 490 patients diagnosed

  9. Mitochondrial mutations drive prostate cancer aggression

    DEFF Research Database (Denmark)

    Hopkins, Julia F.; Sabelnykova, Veronica Y.; Weischenfeldt, Joachim


    Nuclear mutations are well known to drive tumor incidence, aggression and response to therapy. By contrast, the frequency and roles of mutations in the maternally inherited mitochondrial genome are poorly understood. Here we sequence the mitochondrial genomes of 384 localized prostate cancer pati...

  10. Recurrent LDL-receptor mutation causes familial ...

    African Journals Online (AJOL)


    May 5, 1995 ... Three IOW-density lipoprotein receptor (LDLR) gene mutations were previously shown to cause familial hypercholesterolaemia (FH) in up to 90% of affected. Afrikaners. Association of each mutation with a single chromosomal background provided molecular genetic evidence that the proposed 'founder ...

  11. Mutation of human cells by kerosene soot

    Energy Technology Data Exchange (ETDEWEB)

    Skopek, T.R. (Massachusetts Inst. of Tech., Cambridge, MA); Liber, H.L.; Kaden, D.A.; Hites, R.A.; Thilly, W.G.


    The polycyclic aromatic hydrocarbon fraction of a kerosene soot induced forward mutation in human diploid lymphoblasts when coincubated with coincubated with Sprague-Dawley rat liver postmitochondrial supematant. Two components of the kerosene soot extract, benzo(a)pyrene (BP) and cyclopenta(cd)pyrene (CP), were also tested. BP was not mutagenic at the concentration found in the soot extract, although it was active at higher concentrations. The amount of CP present could account for approximately 8% of the total mutation observed with the soot. The results were compared to data obtained previously in a similar mutation assay in Salmonella typhimurium. the protocol described permits the facile assay of mutation at the hgprt locus in human lymphoblasts; such mutation is induced by compounds or complex mixtures requiring mixed-function oxygenase activity for metabolism to genetically active derivatives.

  12. Hypomyelinating Leukodystrophy due to HSPD1 Mutations

    DEFF Research Database (Denmark)

    Kusk, Maria Schioldan; Damgaard, Bodil; Risom, Lotte


    The hypomyelinating leukodystrophies (HMLs) encompass the X-linked Pelizaeus-Merzbacher disease (PMD) caused by PLP1 mutations and known as the classical form of HML as well as Pelizaeus-Merzbacher-like disease (PMLD) (Online Mendelian Inheritance in Man [OMIM] 608804 and OMIM 260600) due to GJC2...... mutations. In addition, mutations in at least 10 other genes are known to cause HMLs. In 2008, an Israeli family with clinical and neuroimaging findings similar to those found in PMD was reported. The patients were found to have a homozygous missense mutation in HSPD1, encoding the mitochondrial heat......-shock protein 60 (Hsp60), and the disorder was defined as the autosomal recessive mitochondrial Hsp60 chaperonopathy (MitCHAP-60) disease. We here report the first case of this severe neurodegenerative disease since it was first described. Given the fact that the families carried the same mutation our patient...

  13. Latex allergy and filaggrin null mutations

    DEFF Research Database (Denmark)

    Carlsen, Berit C; Meldgaard, Michael; Hamann, Dathan


    Objectives Natural rubber latex (NRL) contains over 200 proteins of which 13 have been identified as allergens and the cause of type I latex allergy. Health care workers share a high occupational risk for developing latex allergy. Filaggrin null mutations increase the risk of type I sensitizations...... to aeroallergens and it is possible that filaggrin null mutations also increase the risk of latex allergy. The aim of this paper was to examine the association between filaggrin null mutations and type I latex allergy. Methods Twenty latex allergic and 24 non-latex allergic dentists and dental assistants......, occupationally exposed to latex, were genotyped for filaggrin null mutations R501X and 2282del4. Latex allergy was determined by a positive reaction or a historical positive reaction to a skin prick test with NRL. Results 41 individuals were successfully genotyped. Three individuals were filaggrin mutation...

  14. MT-CYB mutations in hypertrophic cardiomyopathy

    DEFF Research Database (Denmark)

    Hagen, Christian M; Aidt, Frederik H; Havndrup, Ole


    Mitochondrial dysfunction is a characteristic of heart failure. Mutations in mitochondrial DNA, particularly in MT-CYB coding for cytochrome B in complex III (CIII), have been associated with isolated hypertrophic cardiomyopathy (HCM). We hypothesized that MT-CYB mutations might play an important...... and m.15482T>C; p.S246P were identified. Modeling showed that the p.C93Y mutation leads to disruption of the tertiary structure of Cytb by helix displacement, interfering with protein-heme interaction. The p.S246P mutation induces a diproline structure, which alters local secondary structure and induces...... of HCM patients. We propose that further patients with HCM should be examined for mutations in MT-CYB in order to clarify the role of these variants....

  15. Somatic mutations in cerebral cortical malformations. (United States)

    Jamuar, Saumya S; Lam, Anh-Thu N; Kircher, Martin; D'Gama, Alissa M; Wang, Jian; Barry, Brenda J; Zhang, Xiaochang; Hill, Robert Sean; Partlow, Jennifer N; Rozzo, Aldo; Servattalab, Sarah; Mehta, Bhaven K; Topcu, Meral; Amrom, Dina; Andermann, Eva; Dan, Bernard; Parrini, Elena; Guerrini, Renzo; Scheffer, Ingrid E; Berkovic, Samuel F; Leventer, Richard J; Shen, Yiping; Wu, Bai Lin; Barkovich, A James; Sahin, Mustafa; Chang, Bernard S; Bamshad, Michael; Nickerson, Deborah A; Shendure, Jay; Poduri, Annapurna; Yu, Timothy W; Walsh, Christopher A


    Although there is increasing recognition of the role of somatic mutations in genetic disorders, the prevalence of somatic mutations in neurodevelopmental disease and the optimal techniques to detect somatic mosaicism have not been systematically evaluated. Using a customized panel of known and candidate genes associated with brain malformations, we applied targeted high-coverage sequencing (depth, ≥200×) to leukocyte-derived DNA samples from 158 persons with brain malformations, including the double-cortex syndrome (subcortical band heterotopia, 30 persons), polymicrogyria with megalencephaly (20), periventricular nodular heterotopia (61), and pachygyria (47). We validated candidate mutations with the use of Sanger sequencing and, for variants present at unequal read depths, subcloning followed by colony sequencing. Validated, causal mutations were found in 27 persons (17%; range, 10 to 30% for each phenotype). Mutations were somatic in 8 of the 27 (30%), predominantly in persons with the double-cortex syndrome (in whom we found mutations in DCX and LIS1), persons with periventricular nodular heterotopia (FLNA), and persons with pachygyria (TUBB2B). Of the somatic mutations we detected, 5 (63%) were undetectable with the use of traditional Sanger sequencing but were validated through subcloning and subsequent sequencing of the subcloned DNA. We found potentially causal mutations in the candidate genes DYNC1H1, KIF5C, and other kinesin genes in persons with pachygyria. Targeted sequencing was found to be useful for detecting somatic mutations in patients with brain malformations. High-coverage sequencing panels provide an important complement to whole-exome and whole-genome sequencing in the evaluation of somatic mutations in neuropsychiatric disease. (Funded by the National Institute of Neurological Disorders and Stroke and others.).

  16. The CDC Hemophilia A Mutation Project (CHAMP) mutation list: a new online resource. (United States)

    Payne, Amanda B; Miller, Connie H; Kelly, Fiona M; Michael Soucie, J; Craig Hooper, W


    Genotyping efforts in hemophilia A (HA) populations in many countries have identified large numbers of unique mutations in the Factor VIII gene (F8). To assist HA researchers conducting genotyping analyses, we have developed a listing of F8 mutations including those listed in existing locus-specific databases as well as those identified in patient populations and reported in the literature. Each mutation was reviewed and uniquely identified using Human Genome Variation Society (HGVS) nomenclature standards for coding DNA and predicted protein changes as well as traditional nomenclature based on the mature, processed protein. Listings also include the associated hemophilia severity classified by International Society of Thrombosis and Haemostasis (ISTH) criteria, associations of the mutations with inhibitors, and reference information. The mutation list currently contains 2,537 unique mutations known to cause HA. HA severity caused by the mutation is available for 2,022 mutations (80%) and information on inhibitors is available for 1,816 mutations (72%). The CDC Hemophilia A Mutation Project (CHAMP) Mutation List is available at for download and search and will be updated quarterly based on periodic literature reviews and submitted reports. Published 2012. This Article is a US Government work and is in the public domain in the USA.

  17. HPMV: human protein mutation viewer - relating sequence mutations to protein sequence architecture and function changes. (United States)

    Sherman, Westley Arthur; Kuchibhatla, Durga Bhavani; Limviphuvadh, Vachiranee; Maurer-Stroh, Sebastian; Eisenhaber, Birgit; Eisenhaber, Frank


    Next-generation sequencing advances are rapidly expanding the number of human mutations to be analyzed for causative roles in genetic disorders. Our Human Protein Mutation Viewer (HPMV) is intended to explore the biomolecular mechanistic significance of non-synonymous human mutations in protein-coding genomic regions. The tool helps to assess whether protein mutations affect the occurrence of sequence-architectural features (globular domains, targeting signals, post-translational modification sites, etc.). As input, HPMV accepts protein mutations - as UniProt accessions with mutations (e.g. HGVS nomenclature), genome coordinates, or FASTA sequences. As output, HPMV provides an interactive cartoon showing the mutations in relation to elements of the sequence architecture. A large variety of protein sequence architectural features were selected for their particular relevance to mutation interpretation. Clicking a sequence feature in the cartoon expands a tree view of additional information including multiple sequence alignments of conserved domains and a simple 3D viewer mapping the mutation to known PDB structures, if available. The cartoon is also correlated with a multiple sequence alignment of similar sequences from other organisms. In cases where a mutation is likely to have a straightforward interpretation (e.g. a point mutation disrupting a well-understood targeting signal), this interpretation is suggested. The interactive cartoon can be downloaded as standalone viewer in Java jar format to be saved and viewed later with only a standard Java runtime environment. The HPMV website is: .

  18. The CDC Hemophilia A Mutation Project (CHAMP) Mutation List: a New Online Resource (United States)

    Payne, Amanda B.; Miller, Connie H.; Kelly, Fiona M.; Soucie, J. Michael; Hooper, W. Craig


    Genotyping efforts in hemophilia A (HA) populations in many countries have identified large numbers of unique mutations in the Factor VIII gene (F8). To assist HA researchers conducting genotyping analyses, we have developed a listing of F8 mutations including those listed in existing locus-specific databases as well as those identified in patient populations and reported in the literature. Each mutation was reviewed and uniquely identified using Human Genome Variation Society (HGVS) nomenclature standards for coding DNA and predicted protein changes as well as traditional nomenclature based on the mature, processed protein. Listings also include the associated hemophilia severity classified by International Society of Thrombosis and Haemostasis (ISTH) criteria, associations of the mutations with inhibitors, and reference information. The mutation list currently contains 2,537 unique mutations known to cause HA. HA severity caused by the mutation is available for 2,022 mutations (80%) and information on inhibitors is available for 1,816 mutations (72%). The CDC Hemophilia A Mutation Project (CHAMP) Mutation List is available at for download and search and will be updated quarterly based on periodic literature reviews and submitted reports. PMID:23280990

  19. Temperature Sensitive Nanocapsule of Complex Structural Form for Methane Storage

    Directory of Open Access Journals (Sweden)

    Suyetin MV


    Full Text Available Abstract The processes of methane adsorption, storage and desorption by the nanocapsule are investigated with molecular-dynamic modeling method. The specific nanocapsule shape defines its functioning uniqueness: methane is adsorbed under 40 MPa and at normal temperature with further blocking of methane molecules the K@C601+ endohedral complex in the nanocapsule by external electric field, the storage is performed under normal external conditions, and methane desorption is performed at 350 K. The methane content in the nanocapsule during storage reaches 11.09 mass%. The nanocapsule consists of tree parts: storage chamber, junction and blocking chamber. The storage chamber comprises the nanotube (20,20. The blocking chamber is a short nanotube (20,20 with three holes. The junction consists of the nanotube (10,10 and nanotube (8,8; moreover, the nanotube (8,8 is connected with the storage chamber and nanotube (10,10 with the blocking chamber. The blocking chamber is opened and closed by the transfer of the K@C60 1+ endohedral complex under electrostatic field action.

  20. Temperature Sensitivity of Neural Tube Defects in Zoep Mutants. (United States)

    Ma, Phyo; Swartz, Morgan R; Kindt, Lexy M; Kangas, Ashley M; Liang, Jennifer Ostrom


    Neural tube defects (NTD) occur when the flat neural plate epithelium fails to fold into the neural tube, the precursor to the brain and spinal cord. Squint (Sqt/Ndr1), a Nodal ligand, and One-eyed pinhead (Oep), a component of the Nodal receptor, are required for anterior neural tube closure in zebrafish. The NTD in sqt and Zoep mutants are incompletely penetrant. The penetrance of several defects in sqt mutants increases upon heat or cold shock. In this project, undergraduate students tested whether temperature influences the Zoep open neural tube phenotype. Single pairs of adults were spawned at 28.5°C, the normal temperature for zebrafish, and one half of the resulting embryos were moved to 34°C at different developmental time points. Analysis of variance indicated temperature and clutch/genetic background significantly contributed to the penetrance of the open neural tube phenotype. Heat shock affected the embryos only at or before the midblastula stage. Many factors, including temperature changes in the mother, nutrition, and genetic background, contribute to NTD in humans. Thus, sqt and Zoep mutants may serve as valuable models for studying the interactions between genetics and the environment during neurulation.

  1. Identification of a novel temperature sensitive promoter in cho cells

    Directory of Open Access Journals (Sweden)

    Hesse Friedemann


    Full Text Available Abstract Background The Chinese hamster ovary (CHO expression system is the leading production platform for manufacturing biopharmaceuticals for the treatment of numerous human diseases. Efforts to optimize the production process also include the genetic construct encoding the therapeutic gene. Here we report about the successful identification of an endogenous highly active gene promoter obtained from CHO cells which shows conditionally inducible gene expression at reduced temperature. Results Based on CHO microarray expression data abundantly transcribed genes were selected as potential promoter candidates. The S100a6 (calcyclin and its flanking regions were identified from a genomic CHO-K1 lambda-phage library. Computational analyses showed a predicted TSS, a TATA-box and several TFBSs within the 1.5 kb region upstream the ATG start signal. Various constructs were investigated for promoter activity at 37°C and 33°C in transient luciferase reporter gene assays. Most constructs showed expression levels even higher than the SV40 control and on average a more than two-fold increase at lower temperature. We identified the core promoter sequence (222 bp comprising two SP1 sites and could show a further increase in activity by duplication of this minimal sequence. Conclusions This novel CHO promoter permits conditionally high-level gene expression. Upon a shift to 33°C, a two to three-fold increase of basal productivity (already higher than SV40 promoter is achieved. This property is of particular advantage for a process with reduced expression during initial cell growth followed by the production phase at low temperature with a boost in expression. Additionally, production of toxic proteins becomes feasible, since cell metabolism and gene expression do not directly interfere. The CHO S100a6 promoter can be characterized as cold-shock responsive with the potential for improving process performance of mammalian expression systems.

  2. Temperature sensitivity of the oxygenation reaction of stripped ...

    African Journals Online (AJOL)

    "'mne hody of water. This study exumines the oxygen affinities of haemoglobin solutions. stripped hy gel flitruton chromatography, of two. Orange River fishes. L C(f/Jell ds and C. gariepifHH,

  3. Temperature Sensitive Optical Phenomena in Heavy Metal Halide Films. (United States)


    at 25°C. - 152 - -.5 .5 p____•__s_ —a~~~~ -- - -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.5— - - - -——-- .5--- -.5- - -.5 -.5, ~~~~ ‘4- P~11_~PM1 ~ SOIl ...detector ( narcissus effect). Figure 2.6-4. Thermographic image of Pb12-on-glass sample taken using 8 to l4ii wavelength radiation, 199 - - L

  4. Magnetocaloric effect in temperature-sensitive magnetic fluids

    Indian Academy of Sciences (India)


    The pyromagnetic coefficient for all the materials were obtained and it was found that this property depends on physical and magnetic ... Magnetic fluid; pyromagnetic coefficient; Curie temperature. 1. Introduction. A magnetic fluid .... fluid, the distribution of particle size generally follows the log-normal distribution function ...

  5. Temperature-sensitive photoreactivation of cyclobutane thymine dimer in soybean. (United States)

    Yamamoto, Ayumi; Tanbir, Najrana; Hirouchi, Tokuhisa; Teranishi, Mika; Hidema, Jun; Morioka, Hiroshi; Yamamoto, Kazuo


    UV radiation induces the formation of two classes of photoproducts in DNA, the cyclobutane pyrimidine dimer (CPD) and the pyrimidine 6-4 pyrimidone photoproduct. CPDs in plants are repaired by class II CPD photolyase via a UV-A/blue light-dependent mechanism. The genes for the class II CPD photolyase have been cloned from higher plants such as Arabidopsis, Cucumis sativus (cucumber), Oryza sativa (rice) and Spinacia oleracea (spinach). Flavin adenine dinucleotide (FAD) has been identified as a cofactor. Here we report the isolation and characterization of the CPD photolyase cDNA from soybean (Glycin max). The sequence of amino acids predicted from the cDNA sequence was highly homologous to sequences of higher plant class II CPD photolyases. When the cDNA was expressed in a photolyase-deficient Escherichia coli, photoreactivation activity was partially restored by illumination with a fluorescent light. The purified enzyme showed CPD binding and light-dependent photoreactivation activities in vitro. When soybean CPD photolyase was heat-treated in vitro from 25 degrees C to 45 degrees C for 3 min, thymine dimer-binding activity and photoreactivation activity were decreased, and FAD was released from the enzyme. On the other hand, when the enzyme-CPD complex was heat-treated, photoreactivation activity was stable. We argue that FAD in the soybean CPD photolyase is labile for temperature, but once the enzyme-CPD complex has formed, FAD becomes tightly bound to the enzyme or complex.

  6. Mutation profiling of adenoid cystic carcinomas from multiple anatomical sites identifies mutations in the RAS pathway, but no KIT mutations (United States)

    Wetterskog, Daniel; Wilkerson, Paul M; Rodrigues, Daniel N; Lambros, Maryou B; Fritchie, Karen; Andersson, Mattias K; Natrajan, Rachael; Gauthier, Arnaud; Di Palma, Silvana; Shousha, Sami; Gatalica, Zoran; Töpfer, Chantal; Vukovic, Vesna; A’Hern, Roger; Weigelt, Britta; Vincent-Salomon, Anne; Stenman, Göran; Rubin, Brian P; Reis-Filho, Jorge S


    Aims The majority of adenoid cystic carcinomas (AdCCs), regardless of anatomical site, harbour the MYB–NFIB fusion gene. The aim of this study was to characterize the repertoire of somatic genetic events affecting known cancer genes in AdCCs. Methods and results DNA was extracted from 13 microdissected breast AdCCs, and subjected to a mutation survey using the Sequenom OncoCarta Panel v1.0. Genes found to be mutated in any of the breast AdCCs and genes related to the same canonical molecular pathways, as well as KIT, a proto-oncogene whose protein product is expressed in AdCCs, were sequenced in an additional 68 AdCCs from various anatomical sites by Sanger sequencing. Using the Sequenom MassARRAY platform and Sanger sequencing, mutations in BRAF and HRAS were identified in three and one cases, respectively (breast, and head and neck). KIT, which has previously been reported to be mutated in AdCCs, was also investigated, but no mutations were identified. Conclusions Our results demonstrate that mutations in genes pertaining to the canonical RAS pathway are found in a minority of AdCCs, and that activating KIT mutations are either absent or remarkably rare in these cancers, and unlikely to constitute a driver and therapeutic target for patients with AdCC. PMID:23398044

  7. Fitness is strongly influenced by rare mutations of large effect in a microbial mutation accumulation experiment. (United States)

    Heilbron, Karl; Toll-Riera, Macarena; Kojadinovic, Mila; MacLean, R Craig


    Our understanding of the evolutionary consequences of mutation relies heavily on estimates of the rate and fitness effect of spontaneous mutations generated by mutation accumulation (MA) experiments. We performed a classic MA experiment in which frequent sampling of MA lines was combined with whole genome resequencing to develop a high-resolution picture of the effect of spontaneous mutations in a hypermutator (ΔmutS) strain of the bacterium Pseudomonas aeruginosa. After ∼644 generations of mutation accumulation, MA lines had accumulated an average of 118 mutations, and we found that average fitness across all lines decayed linearly over time. Detailed analyses of the dynamics of fitness change in individual lines revealed that a large fraction of the total decay in fitness (42.3%) was attributable to the fixation of rare, highly deleterious mutations (comprising only 0.5% of fixed mutations). Furthermore, we found that at least 0.64% of mutations were beneficial and probably fixed due to positive selection. The majority of mutations that fixed (82.4%) were base substitutions and we failed to find any signatures of selection on nonsynonymous or intergenic mutations. Short indels made up a much smaller fraction of the mutations that were fixed (17.4%), but we found evidence of strong selection against indels that caused frameshift mutations in coding regions. These results help to quantify the amount of natural selection present in microbial MA experiments and demonstrate that changes in fitness are strongly influenced by rare mutations of large effect. Copyright © 2014 by the Genetics Society of America.

  8. Dynamics and Fate of Beneficial Mutations Under Lineage Contamination by Linked Deleterious Mutations (United States)

    Pénisson, Sophie; Singh, Tanya; Sniegowski, Paul


    Beneficial mutations drive adaptive evolution, yet their selective advantage does not ensure their fixation. Haldane’s application of single-type branching process theory showed that genetic drift alone could cause the extinction of newly arising beneficial mutations with high probability. With linkage, deleterious mutations will affect the dynamics of beneficial mutations and might further increase their extinction probability. Here, we model the lineage dynamics of a newly arising beneficial mutation as a multitype branching process. Our approach accounts for the combined effects of drift and the stochastic accumulation of linked deleterious mutations, which we call lineage contamination. We first study the lineage-contamination phenomenon in isolation, deriving dynamics and survival probabilities (the complement of extinction probabilities) of beneficial lineages. We find that survival probability is zero when U≳sb, where U is deleterious mutation rate and sb is the selective advantage of the beneficial mutation in question, and is otherwise depressed below classical predictions by a factor bounded from below by ∼1−U/sb. We then put the lineage contamination phenomenon into the context of an evolving population by incorporating the effects of background selection. We find that, under the combined effects of lineage contamination and background selection, ensemble survival probability is never zero but is depressed below classical predictions by a factor bounded from below by e−εU/s¯b, where s¯b is mean selective advantage of beneficial mutations, and ε=1−e−1≈0.63. This factor, and other bounds derived from it, are independent of the fitness effects of deleterious mutations. At high enough mutation rates, lineage contamination can depress fixation probabilities to values that approach zero. This fact suggests that high mutation rates can, perhaps paradoxically, (1) alleviate competition among beneficial mutations, or (2) potentially even shut

  9. In vivo transgenic mutation assays. (United States)

    Thybaud, Véronique; Dean, Stephen; Nohmi, Takehiko; de Boer, Johan; Douglas, George R; Glickman, Barry W; Gorelick, Nancy J; Heddle, John A; Heflich, Robert H; Lambert, Iain; Martus, Hans-Jörg; Mirsalis, Jon C; Suzuki, Takayoshi; Yajima, Nobuhiro


    Transgenic rodent gene-mutation models provide relatively quick and statistically reliable assays for gene mutations in the DNA from any tissue. This report summarizes those issues that have been agreed upon at a previous IWGT meeting [Environ. Mol. Mutagen. 35 (2000) 253], and discusses in depth those issues for which no consensus was reached before. It was previously agreed that for regulatory applications, assays should be based upon neutral genes, be generally available in several laboratories, and be readily transferable. For phage-based assays, five to ten animals per group should be analyzed, assuming a spontaneous mutant frequency (MF) of approximately 3x10(-5) mutants/locus and 125,000-300,000 plaque or colony forming units (pfu or cfu) per tissue per animal. A full set of data should be generated for a vehicle control and two dose groups. Concurrent positive control animals are only necessary during validation, but positive control DNA must be included in each plating. Tissues should be processed and analyzed in a blocked design, where samples from negative control, positive control and each treatment group are processed together. The total number of pfus or cfus and the MF for each tissue and animal are reported. Statistical tests should consider the animal as the experimental unit. Nonparametric statistical tests are recommended. A positive result is a statistically significant dose-response and/or statistically significant increase in any dose group compared to concurrent negative controls using an appropriate statistical model. A negative result is a statistically non-significant change, with all mean MFs within two standard deviations of the control. During the current workshop, a general protocol was agreed in which animals are treated daily for 28 consecutive days and tissues sampled 3 days after the final treatment. This recommendation could be modified by reducing or increasing the number of treatments or the length of the treatment period, when

  10. Spontaneous deleterious mutation in Arabidopsis thaliana. (United States)

    Schultz, S T; Lynch, M; Willis, J H


    The frequency and selective impact of deleterious mutations are fundamental parameters in evolutionary theory, yet they have not been directly measured in a plant species. To estimate these quantities, we allowed spontaneous mutations to accumulate for 10 generations in 1,000 inbred lines of the annual, self-fertilizing plant Arabidopsis thaliana and assayed fitness differences between generations 0 and 10 in a common garden. Germination rate, fruit set, and number of seeds per fruit each declined by less than 1% per generation in the mutation lines, and total fitness declined by 0.9% per generation. Among-line variances increased in the mutation lines for all traits. Application of an equal-effects model suggests a downwardly biased genomic deleterious mutation rate of 0.1 and a upwardly biased effect of individual mutations on total fitness of 20%. This genomic deleterious mutation rate is consistent with estimates of nucleotide substitution rates in flowering plants, the genome size of Arabidopsis, and the equilibrium inbreeding depression observed in this highly selfing plant species.

  11. Mutational robustness of gene regulatory networks.

    Directory of Open Access Journals (Sweden)

    Aalt D J van Dijk

    Full Text Available Mutational robustness of gene regulatory networks refers to their ability to generate constant biological output upon mutations that change network structure. Such networks contain regulatory interactions (transcription factor-target gene interactions but often also protein-protein interactions between transcription factors. Using computational modeling, we study factors that influence robustness and we infer several network properties governing it. These include the type of mutation, i.e. whether a regulatory interaction or a protein-protein interaction is mutated, and in the case of mutation of a regulatory interaction, the sign of the interaction (activating vs. repressive. In addition, we analyze the effect of combinations of mutations and we compare networks containing monomeric with those containing dimeric transcription factors. Our results are consistent with available data on biological networks, for example based on evolutionary conservation of network features. As a novel and remarkable property, we predict that networks are more robust against mutations in monomer than in dimer transcription factors, a prediction for which analysis of conservation of DNA binding residues in monomeric vs. dimeric transcription factors provides indirect evidence.

  12. KRAS and BRAF mutations in anal carcinoma

    DEFF Research Database (Denmark)

    Serup-Hansen, Eva; Linnemann, Dorte; Høgdall, Estrid


    The EGF receptor (EGFR) is expressed in most cases of anal carcinomas. Anecdotal benefit from EGFR-targeted therapy has been reported in anal cancer and a negative correlation with Kirsten Ras (KRAS) mutation status has been proposed. The purpose of this retrospective study was to investigate...... the frequency and the prognostic value of KRAS and BRAF mutations in a large cohort of patients with anal cancer. One hundred and ninety-three patients with T1-4N0-3M0-1 anal carcinoma were included in the study. Patients were treated with curative (92%) or palliative intent (8%) between January 2000...... and January 2010. KRAS mutations were detected using Therascreen(®)KRAS real-time PCR assay (Qiagen) and V600E or V600D/K BRAF mutations were uncovered using Pyrosequencing. The frequency of KRAS and BRAF mutations was low; KRAS mutations were detected in 1.6% and BRAF mutations in 4.7% of the biopsies...

  13. RNAmute: RNA secondary structure mutation analysis tool

    Directory of Open Access Journals (Sweden)

    Barash Danny


    Full Text Available Abstract Background RNAMute is an interactive Java application that calculates the secondary structure of all single point mutations, given an RNA sequence, and organizes them into categories according to their similarity with respect to the wild type predicted structure. The secondary structure predictions are performed using the Vienna RNA package. Several alternatives are used for the categorization of single point mutations: Vienna's RNAdistance based on dot-bracket representation, as well as tree edit distance and second eigenvalue of the Laplacian matrix based on Shapiro's coarse grain tree graph representation. Results Selecting a category in each one of the processed tables lists all single point mutations belonging to that category. Selecting a mutation displays a graphical drawing of the single point mutation and the wild type, and includes basic information such as associated energies, representations and distances. RNAMute can be used successfully with very little previous experience and without choosing any parameter value alongside the initial RNA sequence. The package runs under LINUX operating system. Conclusion RNAMute is a user friendly tool that can be used to predict single point mutations leading to conformational rearrangements in the secondary structure of RNAs. In several cases of substantial interest, notably in virology, a point mutation may lead to a loss of important functionality such as the RNA virus replication and translation initiation because of a conformational rearrangement in the secondary structure.

  14. Predicting resistance mutations using protein design algorithms. (United States)

    Frey, Kathleen M; Georgiev, Ivelin; Donald, Bruce R; Anderson, Amy C


    Drug resistance resulting from mutations to the target is an unfortunate common phenomenon that limits the lifetime of many of the most successful drugs. In contrast to the investigation of mutations after clinical exposure, it would be powerful to be able to incorporate strategies early in the development process to predict and overcome the effects of possible resistance mutations. Here we present a unique prospective application of an ensemble-based protein design algorithm, K*, to predict potential resistance mutations in dihydrofolate reductase from Staphylococcus aureus using positive design to maintain catalytic function and negative design to interfere with binding of a lead inhibitor. Enzyme inhibition assays show that three of the four highly-ranked predicted mutants are active yet display lower affinity (18-, 9-, and 13-fold) for the inhibitor. A crystal structure of the top-ranked mutant enzyme validates the predicted conformations of the mutated residues and the structural basis of the loss of potency. The use of protein design algorithms to predict resistance mutations could be incorporated in a lead design strategy against any target that is susceptible to mutational resistance.

  15. Benchmarking infrastructure for mutation text mining (United States)


    Background Experimental research on the automatic extraction of information about mutations from texts is greatly hindered by the lack of consensus evaluation infrastructure for the testing and benchmarking of mutation text mining systems. Results We propose a community-oriented annotation and benchmarking infrastructure to support development, testing, benchmarking, and comparison of mutation text mining systems. The design is based on semantic standards, where RDF is used to represent annotations, an OWL ontology provides an extensible schema for the data and SPARQL is used to compute various performance metrics, so that in many cases no programming is needed to analyze results from a text mining system. While large benchmark corpora for biological entity and relation extraction are focused mostly on genes, proteins, diseases, and species, our benchmarking infrastructure fills the gap for mutation information. The core infrastructure comprises (1) an ontology for modelling annotations, (2) SPARQL queries for computing performance metrics, and (3) a sizeable collection of manually curated documents, that can support mutation grounding and mutation impact extraction experiments. Conclusion We have developed the principal infrastructure for the benchmarking of mutation text mining tasks. The use of RDF and OWL as the representation for corpora ensures extensibility. The infrastructure is suitable for out-of-the-box use in several important scenarios and is ready, in its current state, for initial community adoption. PMID:24568600

  16. RET mutations in MEN 2 associated diseases

    Energy Technology Data Exchange (ETDEWEB)

    Hofstra, R.M.W.; Stelwagen, T.; Stulp, R.P. [Univ. of Groningen (Netherlands)] [and others


    Multiple endocrine neoplasia type 2 (MEN 2) comprises three clinically distinct dominantly inherited cancer syndromes namely MEN 2A, MEN 2B and familial medullary thyroid carcinoma (FMTC). Germline (point) mutations of the RET proto-oncogene have been reported to occur in all these syndromes. In MEN 2A and FMTC patients the mutations occurred within codons specifying cysteine residues in the transition of the RET extracellular and transmembrane domains, while in MEN 2B patients we could detect a single RET mutation in the tyrosine kinase domain in all patients. Also in patients suffering from Hirschsprung`s disease (HSCR), mutations in the RET gene have been found. These mutations are spread all over the gene. Several families have been described in which MEN 2 and HSCR are associated. MEN 2A is also found associated with cutaneous lichen amyloidosis (CLA). It might be that specific RET mutations correlate with these disease associations. We therefore scanned DNA from patients from a family with MEN 2A and HSCR, MEN 2A and CLA and CLA only for RET mutations. Results obtained thus far do not support the existence of specific correlations.

  17. Detailed review of transgenic rodent mutation assays. (United States)

    Lambert, Iain B; Singer, Timothy M; Boucher, Sherri E; Douglas, George R


    Induced chromosomal and gene mutations play a role in carcinogenesis and may be involved in the production of birth defects and other disease conditions. While it is widely accepted that in vivo mutation assays are more relevant to the human condition than are in vitro assays, our ability to evaluate mutagenesis in vivo in a broad range of tissues has historically been quite limited. The development of transgenic rodent (TGR) mutation models has given us the ability to detect, quantify, and sequence mutations in a range of somatic and germ cells. This document provides a comprehensive review of the TGR mutation assay literature and assesses the potential use of these assays in a regulatory context. The information is arranged as follows. (1) TGR mutagenicity models and their use for the analysis of gene and chromosomal mutation are fully described. (2) The principles underlying current OECD tests for the assessment of genotoxicity in vitro and in vivo, and also nontransgenic assays available for assessment of gene mutation, are described. (3) All available information pertaining to the conduct of TGR assays and important parameters of assay performance have been tabulated and analyzed. (4) The performance of TGR assays, both in isolation and as part of a battery of in vitro and in vivo short-term genotoxicity tests, in predicting carcinogenicity is described. (5) Recommendations are made regarding the experimental parameters for TGR assays, and the use of TGR assays in a regulatory context.

  18. MutationAligner: a resource of recurrent mutation hotspots in protein domains in cancer. (United States)

    Gauthier, Nicholas Paul; Reznik, Ed; Gao, Jianjiong; Sumer, Selcuk Onur; Schultz, Nikolaus; Sander, Chris; Miller, Martin L


    The MutationAligner web resource, available at, enables discovery and exploration of somatic mutation hotspots identified in protein domains in currently (mid-2015) more than 5000 cancer patient samples across 22 different tumor types. Using multiple sequence alignments of protein domains in the human genome, we extend the principle of recurrence analysis by aggregating mutations in homologous positions across sets of paralogous genes. Protein domain analysis enhances the statistical power to detect cancer-relevant mutations and links mutations to the specific biological functions encoded in domains. We illustrate how the MutationAligner database and interactive web tool can be used to explore, visualize and analyze mutation hotspots in protein domains across genes and tumor types. We believe that MutationAligner will be an important resource for the cancer research community by providing detailed clues for the functional importance of particular mutations, as well as for the design of functional genomics experiments and for decision support in precision medicine. MutationAligner is slated to be periodically updated to incorporate additional analyses and new data from cancer genomics projects. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  19. Melanoma: from mutations to medicine (United States)

    Tsao, Hensin; Chin, Lynda; Garraway, Levi A.; Fisher, David E.


    Melanoma is often considered one of the most aggressive and treatment-resistant human cancers. It is a disease that, due to the presence of melanin pigment, was accurately diagnosed earlier than most other malignancies and that has been subjected to countless therapeutic strategies. Aside from early surgical resection, no therapeutic modality has been found to afford a high likelihood of curative outcome. However, discoveries reported in recent years have revealed a near avalanche of breakthroughs in the melanoma field—breakthroughs that span fundamental understanding of the molecular basis of the disease all the way to new therapeutic strategies that produce unquestionable clinical benefit. These discoveries have been born from the successful fruits of numerous researchers working in many—sometimes-related, although also distinct—biomedical disciplines. Discoveries of frequent mutations involving BRAF(V600E), developmental and oncogenic roles for the microphthalmia-associated transcription factor (MITF) pathway, clinical efficacy of BRAF-targeted small molecules, and emerging mechanisms underlying resistance to targeted therapeutics represent just a sample of the findings that have created a striking inflection in the quest for clinically meaningful progress in the melanoma field. PMID:22661227

  20. Hypertrophic cardiomyopathy clinical phenotype is independent of gene mutation and mutation dosage. (United States)

    Viswanathan, Shiv Kumar; Sanders, Heather K; McNamara, James W; Jagadeesan, Aravindakshan; Jahangir, Arshad; Tajik, A Jamil; Sadayappan, Sakthivel


    Over 1,500 gene mutations are known to cause hypertrophic cardiomyopathy (HCM). Previous studies suggest that cardiac β-myosin heavy chain (MYH7) gene mutations are commonly associated with a more severe phenotype, compared to cardiac myosin binding protein-C (MYBPC3) gene mutations with milder phenotype, incomplete penetrance and later age of onset. Compound mutations can worsen the phenotype. This study aimed to validate these comparative differences in a large cohort of individuals and families with HCM. We performed genome-phenome correlation among 80 symptomatic HCM patients, 35 asymptomatic carriers and 35 non-carriers, using an 18-gene clinical diagnostic HCM panel. A total of 125 mutations were identified in 14 genes. MYBPC3 and MYH7 mutations contributed to 50.0% and 24.4% of the HCM patients, respectively, suggesting that MYBPC3 mutations were the most frequent cause of HCM in our cohort. Double mutations were found in only nine HCM patients (7.8%) who were phenotypically indistinguishable from single-mutation carriers. Comparisons of clinical parameters of MYBPC3 and MYH7 mutants were not statistically significant, but asymptomatic carriers had high left ventricular ejection fraction and diastolic dysfunction when compared to non-carriers. The presence of double mutations increases the risk for symptomatic HCM with no change in severity, as determined in this study subset. The pathologic effects of MYBPC3 and MYH7 were found to be independent of gene mutation location. Furthermore, HCM pathology is independent of protein domain disruption in both MYBPC3 and MYH7. These data provide evidence that MYBPC3 mutations constitute the preeminent cause of HCM and that they are phenotypically indistinguishable from HCM caused by MYH7 mutations.

  1. p53 mutations in urinary bladder cancer


    Berggren, P; Steineck, G; Adolfsson, J; Hansson, J; Jansson, O; Larsson, P; Sandstedt, B; Wijkstr?m, H; Hemminki, K


    We have screened for mutations in exons 5?8 of the p53 gene in a series consisting of 189 patients with urinary bladder neoplasms. 82 (44%) neoplasms were lowly malignant (Ta, G1?G2a) and 106 (56%) were highly malignant (G2b?G4 or ?T1). Only one mutation was in a lowly malignant urinary bladder neoplasm, in total we found p53 mutations in 26 (14%) of the 189 patients. 30% of the samples had loss of heterozygosity (LOH) for one or both of the p53 exogenic (CA)n repeat and the p53 intragenic (A...

  2. A New Mutation in Blau Syndrome

    Directory of Open Access Journals (Sweden)

    Cengiz Zeybek


    Full Text Available Blau syndrome is a rare, autosomal dominant, granulomatous autoinflammatory disease. The classic triad of the disease includes recurrent uveitis, granulomatous dermatitis, and symmetrical arthritis. Blau syndrome is related to mutations located at the 16q12.2–13 gene locus. To date, 11 NOD2 gene mutations causing Blau syndrome have been described. Here, we describe a 5-year-old male patient who presented with Blau syndrome associated with a novel sporadic gene mutation that has not been reported previously.

  3. Multiple mutations and mutation combinations in the sodium channel of permethrin resistant mosquitoes, Culex quinquefasciatus (United States)

    Li, Ting; Zhang, Lee; Reid, William R.; Xu, Qiang; Dong, Ke; Liu, Nannan


    A previous study identified 3 nonsynonymous and 6 synonymous mutations in the entire mosquito sodium channel of Culex quinquefasciatus, the prevalence of which were strongly correlated with levels of resistance and increased dramatically following insecticide selection. However, it is unclear whether this is unique to this specific resistant population or is a common mechanism in field mosquito populations in response to insecticide pressure. The current study therefore further characterized these mutations and their combinations in other field and permethrin selected Culex mosquitoes, finding that the co-existence of all 9 mutations was indeed correlated with the high levels of permethrin resistance in mosquitoes. Comparison of mutation combinations revealed several common mutation combinations presented across different field and permethrin selected populations in response to high levels of insecticide resistance, demonstrating that the co-existence of multiple mutations is a common event in response to insecticide resistance across different Cx. quinquefasciatus mosquito populations.

  4. Discovery of mutations for Mendelian disorders. (United States)

    Alkuraya, Fowzan S


    Mendelian mutations are the most medically actionable variants in the human genome and have always played a central role in its functional annotation. Despite the relative ease with which Mendelian mutations are identified compared to other classes of variants, the pace of their discovery has until recently been slow. However, recent technological advances in genomic sequencing have made the prospect of identifying all genes that can harbor Mendelian mutations an achievable near-term goal. The many lessons learned from previous discoveries of Mendelian mutations should inform future studies as I will discuss in this review. Also discussed are some of the challenges that will gain more prominence as we approach the last phase of the effort to map all Mendelian genes.

  5. A new view of genetic mutations

    National Research Council Canada - National Science Library

    Jean-François Picimbon


    ...: chemosensory proteins (CSPs) and odour binding protein (OBP) families. It is worthy to note that these RNA variants are not disease-causing mutations but rather an evolutionary mechanism in microorganisms and insects...

  6. Recurrent LDL-receptor mutation causes familial ...

    African Journals Online (AJOL)


    May 5, 1995 ... amplification refractory mutation system (ARMS)" and single- strand conformation polymorphism (SSCP) method." SSCP analysis was performed on polymerase chain reaction (PCR) products amplified with exon 9-specific oligonucleotides. N2 (5'-GCTCCATCGCCTACCTCTIC-3') and A2 (5'-.

  7. IFITM5 mutations and osteogenesis imperfecta. (United States)

    Hanagata, Nobutaka


    Interferon-induced transmembrane protein 5 (IFITM5) is an osteoblast-specific membrane protein that has been shown to be a positive regulatory factor for mineralization in vitro. However, Ifitm5 knockout mice do not exhibit serious bone abnormalities, and thus the function of IFITM5 in vivo remains unclear. Recently, a single point mutation (c.-14C>T) in the 5' untranslated region of IFITM5 was identified in patients with osteogenesis imperfecta type V (OI-V). Furthermore, a single point mutation (c.119C>T) in the coding region of IFITM5 was identified in OI patients with more severe symptoms than patients with OI-V. Although IFITM5 is not directly involved in the formation of bone in vivo, the reason why IFITM5 mutations cause OI remains a major mystery. In this review, the current state of knowledge of OI pathological mechanisms due to IFITM5 mutations will be reviewed.

  8. Mitochondrial DNA mutations in Parkinson's disease brain

    National Research Council Canada - National Science Library

    David K Simon; Joanne Clark Matott; Janaina Espinosa; Neeta A Abraham


    Dear Editors, We read with interest the publication by Wei et al., Mitochondrial DNA Point Mutations and Relative Copy Number in 1363 Disease and Control Human Brains, Acta Neuropathol Commun. 2017; 5: 13 [4...

  9. Geneticists Repair Mutation in Human Embryo (United States)

    ... broke the mutated gene using a technology called CRISPR-Cas9. Essentially, the process uses genetic techniques to target ... like a pair of molecular scissors. Until now, CRISPR-Cas9 has been used as a lab tool to ...

  10. Titin mutation in familial restrictive cardiomyopathy

    National Research Council Canada - National Science Library

    Peled, Yael; Gramlich, Michael; Yoskovitz, Guy; Feinberg, Micha S; Afek, Arnon; Polak-Charcon, Sylvie; Pras, Elon; Sela, Ben-Ami; Konen, Eli; Weissbrod, Omer; Geiger, Dan; Gordon, Paul M K; Thierfelder, Ludwig; Freimark, Dov; Gerull, Brenda; Arad, Michael


    ...). Other genes associated with RCM include the desmin and familial amyloidosis genes. In the present study we describe familial RCM with severe heart failure triggered by a de novo mutation in TTN, encoding the huge muscle filament protein titin...

  11. Mutations of myelodysplastic syndromes (MDS): An update. (United States)

    Ganguly, Bani Bandana; Kadam, N N


    The plethora of knowledge gained on myelodysplastic syndromes (MDS), a heterogeneous pre-malignant disorder of hematopoietic stem cells, through sequencing of several pathway genes has unveiled molecular pathogenesis and its progression to AML. Evolution of phenotypic classification and risk-stratification based on peripheral cytopenias and blast count has moved to five-tier risk-groups solely concerning chromosomal aberrations. Increased frequency of complex abnormalities, which is associated with genetic instability, defines the subgroup of worst prognosis in MDS. However, the independent effect of monosomal karyotype remains controversial. Recent discoveries on mutations in RNA-splicing machinery (SF3B1, SRSF2, ZRSR2, U2AF1, U2AF2); DNA methylation (TET2, DNMT3A, IDH1/2); chromatin modification (ASXL1, EZH2); transcription factor (TP53, RUNX1); signal transduction/kinases (FLT3, JAK2); RAS pathway (KRAS, NRAS, CBL, NF1, PTPN11); cohesin complex (STAG2, CTCF, SMC1A, RAD21); DNA repair (ATM, BRCC3, DLRE1C, FANCL); and other pathway genes have given insights into the independent effects and interaction of co-occurrence of mutations on disease-phenotype. RNA-splicing and DNA methylation mutations appeared to occur early and are reported as 'founder' mutations in over 50% MDS patients. TET2 mutation, through altered DNA methylation, has been found to have independent prognostic response to hypomethylating agents. Moreover, presence of DNMT3A, TET2 and ASXL1 mutations in normal elderly individuals forms the basis of understanding that accumulation of somatic mutations may not cause direct disease-development; however, cooperation with other mutations in the genes that are frequently mutated in myeloid and other hematopoietic cancers might result in clonal expansion through self-renewal and/or proliferation of hematopoietic stem cells. Identification of small molecules as inhibitors of epigenetic mutations has opened avenues for tailoring targeted drug development. The

  12. Normal mutation rate variants arise in a Mutator (Mut S Escherichia coli population.

    Directory of Open Access Journals (Sweden)

    María-Carmen Turrientes

    Full Text Available The rate at which mutations are generated is central to the pace of evolution. Although this rate is remarkably similar amongst all cellular organisms, bacterial strains with mutation rates 100 fold greater than the modal rates of their species are commonly isolated from natural sources and emerge in experimental populations. Theoretical studies postulate and empirical studies teort the hypotheses that these "mutator" strains evolved in response to selection for elevated rates of generation of inherited variation that enable bacteria to adapt to novel and/or rapidly changing environments. Less clear are the conditions under which selection will favor reductions in mutation rates. Declines in rates of mutation for established populations of mutator bacteria are not anticipated if such changes are attributed to the costs of augmented rates of generation of deleterious mutations. Here we report experimental evidence of evolution towards reduced mutation rates in a clinical isolate of Escherichia coli with an hyper-mutable phenotype due a deletion in a mismatch repair gene, (ΔmutS. The emergence in a ΔmutS background of variants with mutation rates approaching those of the normal rates of strains carrying wild-type MutS was associated with increase in fitness with respect to ancestral strain. We postulate that such an increase in fitness could be attributed to the emergence of mechanisms driving a permanent "aerobic style of life", the negative consequence of this behavior being regulated by the evolution of mechanisms protecting the cell against increased endogenous oxidative radicals involved in DNA damage, and thus reducing mutation rate. Gene expression assays and full sequencing of evolved mutator and normo-mutable variants supports the hypothesis. In conclusion, we postulate that the observed reductions in mutation rate are coincidental to, rather than, the selective force responsible for this evolution.

  13. Optimal Mutation Rates on Static Fitness Landscpes


    Nilsson, M.


    We study the evolution of mutation rates for an asexual population living on a static fitness landscape, consisting of multiple peaks forming an evolutionary staircase. The optimal mutation rate is found by maximizing the diffusion towards higher fitness. Surprisingly the optimal genomic copying fidelity is given by Q = e^(-1/ln(n)) (where n is the genome length), independent of all other parameters in the model. Simulations confirm this theoretical result. We also discuss the relation betwee...

  14. Chymotrypsin C (CTRC) mutations in chronic pancreatitis


    Zhou, Jiayi; Sahin-Tóth, Miklós


    Chronic pancreatitis is a persistent inflammatory disorder characterized by destruction of the pancreatic parenchyma, maldigestion, and chronic pain. Mutations in the CTRC gene encoding the digestive enzyme chymotrypsin C have been shown to increase the risk of chronic pancreatitis in European and Asian populations. Here we review the biochemical properties and physiological functions of human CTRC; summarize the functional defects associated with CTRC mutations and discuss mechanistic models...

  15. TILLING to detect induced mutations in soybean. (United States)

    Cooper, Jennifer L; Till, Bradley J; Laport, Robert G; Darlow, Margaret C; Kleffner, Justin M; Jamai, Aziz; El-Mellouki, Tarik; Liu, Shiming; Ritchie, Rae; Nielsen, Niels; Bilyeu, Kristin D; Meksem, Khalid; Comai, Luca; Henikoff, Steven


    Soybean (Glycine max L. Merr.) is an important nitrogen-fixing crop that provides much of the world's protein and oil. However, the available tools for investigation of soybean gene function are limited. Nevertheless, chemical mutagenesis can be applied to soybean followed by screening for mutations in a target of interest using a strategy known as Targeting Induced Local Lesions IN Genomes (TILLING). We have applied TILLING to four mutagenized soybean populations, three of which were treated with ethyl methanesulfonate (EMS) and one with N-nitroso-N-methylurea (NMU). We screened seven targets in each population and discovered a total of 116 induced mutations. The NMU-treated population and one EMS mutagenized population had similar mutation density (approximately 1/140 kb), while another EMS population had a mutation density of approximately 1/250 kb. The remaining population had a mutation density of approximately 1/550 kb. Because of soybean's polyploid history, PCR amplification of multiple targets could impede mutation discovery. Indeed, one set of primers tested in this study amplified more than a single target and produced low quality data. To address this problem, we removed an extraneous target by pretreating genomic DNA with a restriction enzyme. Digestion of the template eliminated amplification of the extraneous target and allowed the identification of four additional mutant alleles compared to untreated template. The development of four independent populations with considerable mutation density, together with an additional method for screening closely related targets, indicates that soybean is a suitable organism for high-throughput mutation discovery even with its extensively duplicated genome.

  16. TILLING to detect induced mutations in soybean

    Directory of Open Access Journals (Sweden)

    Nielsen Niels


    Full Text Available Abstract Background Soybean (Glycine max L. Merr. is an important nitrogen-fixing crop that provides much of the world's protein and oil. However, the available tools for investigation of soybean gene function are limited. Nevertheless, chemical mutagenesis can be applied to soybean followed by screening for mutations in a target of interest using a strategy known as Targeting Induced Local Lesions IN Genomes (TILLING. We have applied TILLING to four mutagenized soybean populations, three of which were treated with ethyl methanesulfonate (EMS and one with N-nitroso-N-methylurea (NMU. Results We screened seven targets in each population and discovered a total of 116 induced mutations. The NMU-treated population and one EMS mutagenized population had similar mutation density (~1/140 kb, while another EMS population had a mutation density of ~1/250 kb. The remaining population had a mutation density of ~1/550 kb. Because of soybean's polyploid history, PCR amplification of multiple targets could impede mutation discovery. Indeed, one set of primers tested in this study amplified more than a single target and produced low quality data. To address this problem, we removed an extraneous target by pretreating genomic DNA with a restriction enzyme. Digestion of the template eliminated amplification of the extraneous target and allowed the identification of four additional mutant alleles compared to untreated template. Conclusion The development of four independent populations with considerable mutation density, together with an additional method for screening closely related targets, indicates that soybean is a suitable organism for high-throughput mutation discovery even with its extensively duplicated genome.

  17. Homozygous Desmocollin-2 Mutations and Arrhythmogenic Cardiomyopathy. (United States)

    Lorenzon, Alessandra; Pilichou, Kalliopi; Rigato, Ilaria; Vazza, Giovanni; De Bortoli, Marzia; Calore, Martina; Occhi, Gianluca; Carturan, Elisa; Lazzarini, Elisabetta; Cason, Marco; Mazzotti, Elisa; Poloni, Giulia; Mostacciuolo, Maria Luisa; Daliento, Luciano; Thiene, Gaetano; Corrado, Domenico; Basso, Cristina; Bauce, Barbara; Rampazzo, Alessandra


    Dominant mutations in desmocollin-2 (DSC2) gene cause arrhythmogenic cardiomyopathy (ACM), a progressive heart muscle disease characterized by ventricular tachyarrhythmias, heart failure, and risk of juvenile sudden death. Recessive mutations are rare and are associated with a cardiac or cardiocutaneous phenotype. Here, we evaluated the impact of a homozygous founder DSC2 mutation on clinical expression of ACM. An exon-by-exon analysis of the DSC2 coding region was performed in 94 ACM index patients. The c.536A>G (p.D179G) mutation was identified in 5 patients (5.3%), 4 of which resulted to be homozygous carriers. The 5 subjects shared a conserved haplotype, strongly indicating a common founder. Genetic and clinical investigation of probands' families revealed that p.D179G homozygous carriers displayed severe forms of biventricular cardiomyopathy without hair or skin abnormalities. The only heterozygous proband, who carried an additional variant of unknown significance in αT-catenin gene, showed a mild form of ACM without left ventricular involvement. All heterozygous family members were clinically asymptomatic. In conclusion, this is the first homozygous founder mutation in DSC2 gene identified among Italian ACM probands. Our findings provide further evidence of the occurrence of recessive DSC2 mutations in patients with ACM predominantly presenting with biventricular forms of the disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. A novel MERTK mutation causing retinitis pigmentosa. (United States)

    Al-Khersan, Hasenin; Shah, Kaanan P; Jung, Segun C; Rodriguez, Alex; Madduri, Ravi K; Grassi, Michael A


    Retinitis pigmentosa (RP) is a genetically heterogeneous inherited retinal dystrophy. To date, over 80 genes have been implicated in RP. However, the disease demonstrates significant locus and allelic heterogeneity not entirely captured by current testing platforms. The purpose of the present study was to characterize the underlying mutation in a patient with RP without a molecular diagnosis after initial genetic testing. Whole-exome sequencing of the affected proband was performed. Candidate gene mutations were selected based on adherence to expected genetic inheritance pattern and predicted pathogenicity. Sanger sequencing of MERTK was completed on the patient's unaffected mother, affected brother, and unaffected sister to determine genetic phase. Eight sequence variants were identified in the proband in known RP-associated genes. Sequence analysis revealed that the proband was a compound heterozygote with two independent mutations in MERTK, a novel nonsense mutation (c.2179C > T) and a previously reported missense variant (c.2530C > T). The proband's affected brother also had both mutations. Predicted phase was confirmed in unaffected family members. Our study identifies a novel nonsense mutation in MERTK in a family with RP and no prior molecular diagnosis. The present study also demonstrates the clinical value of exome sequencing in determining the genetic basis of Mendelian diseases when standard genetic testing is unsuccessful.

  19. The Mutations Associated with Dilated Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Ruti Parvari


    Full Text Available Cardiomyopathy is an important cause of heart failure and a major indication for heart transplantation in children and adults. This paper describes the state of the genetic knowledge of dilated cardiomyopathy (DCM. The identification of the causing mutation is important since presymptomatic interventions of DCM have proven value in preventing morbidity and mortality. Additionally, as in general in genetic studies, the identification of the mutated genes has a direct clinical impact for the families and population involved. Identifying causative mutations immediately amplifies the possibilities for disease prevention through carrier screening and prenatal testing. This often lifts a burden of social isolation from affected families, since healthy family members can be assured of having healthy children. Identification of the mutated genes holds the potential to lead to the understanding of disease etiology, pathophysiology, and therefore potential therapy. This paper presents the genetic variations, or disease-causing mutations, contributing to the pathogenesis of hereditary DCM, and tries to relate these to the functions of the mutated genes.

  20. Apparent directional selection by biased pleiotropic mutation. (United States)

    Tanaka, Yoshinari


    Pleiotropic effects of deleterious mutations are considered to be among the factors responsible for genetic constraints on evolution by long-term directional selection acting on a quantitative trait. If pleiotropic phenotypic effects are biased in a particular direction, mutations generate apparent directional selection, which refers to the covariance between fitness and the trait owing to a linear association between the number of mutations possessed by individuals and the genotypic values of the trait. The present analysis has shown how the equilibrium mean value of the trait is determined by a balance between directional selection and biased pleiotropic mutations. Assuming that genes act additively both on the trait and on fitness, the total variance-standardized directional selection gradient was decomposed into apparent and true components. Experimental data on mutation bias from the bristle traits of Drosophila and life history traits of Daphnia suggest that apparent selection explains a small but significant fraction of directional selection pressure that is observed in nature; the data suggest that changes induced in a trait by biased pleiotropic mutation (i.e., by apparent directional selection) are easily compensated for by (true) directional selection.

  1. TOX3 mutations in breast cancer.

    Directory of Open Access Journals (Sweden)

    James Owain Jones

    Full Text Available TOX3 maps to 16q12, a region commonly lost in breast cancers and recently implicated in the risk of developing breast cancer. However, not much is known of the role of TOX3 itself in breast cancer biology. This is the first study to determine the importance of TOX3 mutations in breast cancers. We screened TOX3 for mutations in 133 breast tumours and identified four mutations (three missense, one in-frame deletion of 30 base pairs in six primary tumours, corresponding to an overall mutation frequency of 4.5%. One potentially deleterious missense mutation in exon 3 (Leu129Phe was identified in one tumour (genomic DNA and cDNA. Whilst copy number changes of 16q12 are common in breast cancer, our data show that mutations of TOX3 are present at low frequency in tumours. Our results support that TOX3 should be further investigated to elucidate its role in breast cancer biology.

  2. A DSPP Mutation Causing Dentinogenesis Imperfecta and Characterization of the Mutational Effect

    Directory of Open Access Journals (Sweden)

    Sook-Kyung Lee


    Full Text Available Mutations in the DSPP gene have been identified in nonsyndromic hereditary dentin defects, but the genotype-phenotype correlations are not fully understood. Recently, it has been demonstrated that the mutations of DSPP affecting the IPV leader sequence result in mutant DSPP retention in rough endoplasmic reticulum (ER. In this study, we identified a Korean family with dentinogenesis imperfecta type III. To identify the disease causing mutation in this family, we performed mutational analysis based on candidate gene sequencing. Exons and exon-intron boundaries of DSPP gene were sequenced, and the effects of the identified mutation on the pre-mRNA splicing and protein secretion were investigated. Candidate gene sequencing revealed a mutation (c.50C > T, p.P17L in exon 2 of the DSPP gene. The splicing assay showed that the mutation did not influence pre-mRNA splicing. However, the mutation interfered with protein secretion and resulted in the mutant protein remaining largely in the ER. These results suggest that the mutation affects ER-to-Golgi apparatus export and results in the reduction of secreted DSPP and ER overload. This may induce cell stress and damage processing and/or transport of dentin matrix proteins or other critical proteins.

  3. Study of mutations in Jordanian patients with haemophilia A: identification of five novel mutations. (United States)

    Awidi, A; Ramahi, M; Alhattab, D; Mefleh, R; Dweiri, M; Bsoul, N; Magablah, A; Arafat, E; Barqawi, M; Bishtawi, M; Haddadeen, E; Falah, M; Tarawneh, B; Swaidan, S; Fauori, S


    Haemophilia A (HA) is an X-linked recessive bleeding disorder caused by mutations in the factor VIII gene (F8), which encodes factor VIII (FVIII) protein, a plasma glycoprotein, that plays an important role in the blood coagulation cascade. In the present study, our aim was to identify F8 gene mutations in HA patients from Jordan. One hundred and seventy-five HA patients from 42 unrelated families were included in this study. Among these patients, 117 (67%) had severe HA, 13 (7%) had moderate HA and 45 (26%) had mild HA. Severe patients were first tested for intron-22 inversion using long range polymerase chain reaction (PCR), then negative patients were tested for intron-1 inversion using PCR. Sequencing for the entire F8 gene was performed for all severe HA patients who were found negative for intron-22 and -1 inversions and it was also performed for moderate and mild HA patients. HA causative mutations were identified in all patients. Intron-22 and -1 inversions were detected in 52% and 2% of families respectively. Beside these two mutations, 19 different mutations were identified, which include 15 missense and four frameshift mutations. Five novel mutations were identified including one frameshift and four missense mutations. No large deletions or nonsense mutations were detected in patients who participated in this study. Only 17 patients with severe HA were found positive for FVIII inhibitors. The data presented will play an important role for genetic counselling and health care of HA patients in Jordan.

  4. Spontaneous Mutation Rate of Measles Virus: Direct Estimation Based on Mutations Conferring Monoclonal Antibody Resistance (United States)

    Schrag, Stephanie J.; Rota, Paul A.; Bellini, William J.


    High mutation rates typical of RNA viruses often generate a unique viral population structure consisting of a large number of genetic microvariants. In the case of viral pathogens, this can result in rapid evolution of antiviral resistance or vaccine-escape mutants. We determined a direct estimate of the mutation rate of measles virus, the next likely target for global elimination following poliovirus. In a laboratory tissue culture system, we used the fluctuation test method of estimating mutation rate, which involves screening a large number of independent populations initiated by a small number of viruses each for the presence or absence of a particular single point mutation. The mutation we focused on, which can be screened for phenotypically, confers resistance to a monoclonal antibody (MAb 80-III-B2). The entire H gene of a subset of mutants was sequenced to verify that the resistance phenotype was associated with single point mutations. The epitope conferring MAb resistance was further characterized by Western blot analysis. Based on this approach, measles virus was estimated to have a mutation rate of 9 × 10−5 per base per replication and a genomic mutation rate of 1.43 per replication. The mutation rates we estimated for measles virus are comparable to recent in vitro estimates for both poliovirus and vesicular stomatitis virus. In the field, however, measles virus shows marked genetic stability. We briefly discuss the evolutionary implications of these results. PMID:9847306

  5. IDH1 mutated low grade astrocytoma occurring in MSH2 mutated Lynch syndrome family

    Directory of Open Access Journals (Sweden)

    Alaa Alkhotani


    Full Text Available Lynch syndrome (LS is an autosomal dominant tumour predisposition syndrome caused by a germline mutation in one of the DNA mismatch repair (MMR genes.Patients with these mutations have an increased risk of brain tumours, the vast majority of which are glioblastomas and medulloblastomas, and their occurrence has been termed Turcot Syndrome. The case presented herein of a member of a Lynch syndrome family with an MSH2 mutation expands the spectrum of brain tumours occurring in Lynch syndrome to include low grade astrocytomas, and is the first reported case of an IDH1 (R132H mutated brain tumour occurring in a Lynch syndrome family.

  6. GJB2 mutations in deaf population of Ilam (Western Iran): a different pattern of mutation distribution. (United States)

    Mahdieh, Nejat; Mahmoudi, Hamdollah; Ahmadzadeh, Soleiman; Bakhtiyari, Salar


    Hearing loss is the most common sensory defect caused by heterogeneous factors. Up to now, more than 60 mutations in genes have been documented for nonsyndromic hearing loss. Hence, finding the causal gene in affected families could be a laborious and time-consuming process. GJB2 mutations, here, were investigated among deaf subjects of Ilam for the first time. In this study, we studied 62 unrelated patients with non-syndromic autosomal recessive deafness from 62 families. The most common mutation of GJB2, 35delG was checked, followed by direct sequencing of the GJB2 gene for determination of other mutations. In silico analyses were also performed using available software. In nine families, mutations in the connexin 26 gene were observed. In the studied population, R32H was the most common mutation. 35delG, W24X, and R127H were other mutations found in this study. In silico analyses showed pathogenicity of 35delG, R32H, and W24X but not R127H. Low frequency of GJB2 mutations in this population is probably indicative of the fact that other genes may be involved in nonsyndromic hearing loss in Ilam populations. In the other hand, the vicinity of Ilam and Iraq suggests that GJB2 mutations have likely a low frequency in this population.

  7. (A review) Mutation and its role in biotechnology | Sudi | Nigerian ...

    African Journals Online (AJOL)

    Mutations is the process by which a gene or chromosome changes; structurally and the end result of that process. All mutations are not harmful' as beneficial mutations occur frequently among various viruses, and bacteria and also in higher organisms. The Biotechnological role of mutations will be reviewed and discussed.

  8. Splice Site Mutations in the ATP7A Gene

    DEFF Research Database (Denmark)

    Skjørringe, Tina; Tümer, Zeynep; Møller, Lisbeth Birk


    Menkes disease (MD) is caused by mutations in the ATP7A gene. We describe 33 novel splice site mutations detected in patients with MD or the milder phenotypic form, Occipital Horn Syndrome. We review these 33 mutations together with 28 previously published splice site mutations. We investigate 12...... mutations for their effect on the mRNA transcript in vivo. Transcriptional data from another 16 mutations were collected from the literature. The theoretical consequences of splice site mutations, predicted with the bioinformatics tool Human Splice Finder, were investigated and evaluated in relation...

  9. Comprehensive Mutation Analysis in Colorectal Flat Adenomas (United States)

    Voorham, Quirinus J. M.; Carvalho, Beatriz; Spiertz, Angela J.; Claes, Bart; Mongera, Sandra; van Grieken, Nicole C. T.; Grabsch, Heike; Kliment, Martin; Rembacken, Bjorn; van de Wiel, Mark A.; Quirke, Philip; Mulder, Chris J. J.; Lambrechts, Diether; van Engeland, Manon; Meijer, Gerrit A.


    Background Flat adenomas are a subgroup of colorectal adenomas that have been associated with a distinct biology and a more aggressive clinical behavior compared to their polypoid counterparts. In the present study, we aimed to compare the mutation spectrum of 14 cancer genes, between these two phenotypes. Methods A consecutive series of 106 flat and 93 polypoid adenomas was analyzed retrospectively for frequently occurring mutations in “hot spot” regions of KRAS, BRAF, PIK3CA and NRAS, as well as selected mutations in CTNNB1 (β-catenin), EGFR, FBXW7 (CDC4), PTEN, STK11, MAP2K4, SMAD4, PIK3R1 and PDGFRA using a high-throughput genotyping technique. Additionally, APC was analyzed using direct sequencing. Results APC mutations were more frequent in polypoid adenomas compared to flat adenomas (48.5% versus 30.3%, respectively, p = 0.02). Mutations in KRAS, BRAF, NRAS, FBXW7 and CTNNB1 showed similar frequencies in both phenotypes. Between the different subtypes of flat adenomas (0-IIa, LST-F and LST-G) no differences were observed for any of the investigated genes. Conclusion The lower APC mutation rate in flat adenomas compared to polypoid adenomas suggests that disruption of the Wnt-pathway may occur via different mechanisms in these two phenotypes. Furthermore, in contrast to previous observations our results in this large well-defined sample set indicate that there is no significant association between the different morphological phenotypes and mutations in key genes of the RAS-RAF-MAPK pathway. PMID:22848674

  10. Purging deleterious mutations under self fertilization: paradoxical recovery in fitness with increasing mutation rate in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Levi T Morran

    Full Text Available BACKGROUND: The accumulation of deleterious mutations can drastically reduce population mean fitness. Self-fertilization is thought to be an effective means of purging deleterious mutations. However, widespread linkage disequilibrium generated and maintained by self-fertilization is predicted to reduce the efficacy of purging when mutations are present at multiple loci. METHODOLOGY/PRINCIPAL FINDINGS: We tested the ability of self-fertilizing populations to purge deleterious mutations at multiple loci by exposing obligately self-fertilizing populations of Caenorhabditis elegans to a range of elevated mutation rates and found that mutations accumulated, as evidenced by a reduction in mean fitness, in each population. Therefore, purging in obligate selfing populations is overwhelmed by an increase in mutation rate. Surprisingly, we also found that obligate and predominantly self-fertilizing populations exposed to very high mutation rates exhibited consistently greater fitness than those subject to lesser increases in mutation rate, which contradicts the assumption that increases in mutation rate are negatively correlated with fitness. The high levels of genetic linkage inherent in self-fertilization could drive this fitness increase. CONCLUSIONS: Compensatory mutations can be more frequent under high mutation rates and may alleviate a portion of the fitness lost due to the accumulation of deleterious mutations through epistatic interactions with deleterious mutations. The prolonged maintenance of tightly linked compensatory and deleterious mutations facilitated by self-fertilization may be responsible for the fitness increase as linkage disequilibrium between the compensatory and deleterious mutations preserves their epistatic interaction.

  11. New mutations in APOB100 involved in familial hypobetalipoproteinemia

    DEFF Research Database (Denmark)

    Brusgaard, Klaus; Kjaersgaard, Lars; Hansen, Anne-Birthe Bo


    Familial hypolipoproteinemia (FHBL) is characterized by an inherited low plasma level of apolipoprotein B containing lipoproteins. FHBL may be caused by mutations of APOB. Individuals with FHBL typically have intestinal malabsorption and frequently suffer from a deficiency of fat-soluble vitamins....... Most mutations that cause FHBL are APOB truncating mutations. Here we describe a patient with FHBL caused by a novel truncating mutation together with a novel missense mutation....

  12. MEN1 redefined, a clinical comparison of mutation-positive and mutation-negative patients

    NARCIS (Netherlands)

    Laat, J.M. de; Luijt, R.B. van der; Pieterman, C.R.; Oostveen, M.P.; Hermus, A.R.; Dekkers, O.M.; Herder, W.W. de; Horst-Schrivers, A.N. van der; Drent, M.L.; Bisschop, P.H.; Havekes, B.; Vriens, M.R.; Valk, G.D.


    BACKGROUND: Multiple Endocrine Neoplasia type 1 (MEN1) is diagnosed when two out of the three primary MEN1-associated endocrine tumors occur in a patient. Up to 10-30 % of those patients have no mutation in the MEN1 gene. It is unclear if the phenotype and course of the disease of mutation-negative

  13. MEN1 redefined, a clinical comparison of mutation-positive and mutation-negative patients

    NARCIS (Netherlands)

    de Laat, Joanne M.; van der Luijt, Rob B.; Pieterman, Carolina R. C.; Oostveen, Maria P.; Hermus, Ad R.; Dekkers, Olaf M.; de Herder, Wouter W.; van der Horst-Schrivers, Anouk N.; Drent, Madeleine L.; Bisschop, Peter H.; Havekes, Bas; Vriens, Menno R.; Valk, Gerlof D.


    Multiple Endocrine Neoplasia type 1 (MEN1) is diagnosed when two out of the three primary MEN1-associated endocrine tumors occur in a patient. Up to 10-30 % of those patients have no mutation in the MEN1 gene. It is unclear if the phenotype and course of the disease of mutation-negative patients is

  14. MEN1 redefined, a clinical comparison of mutation-positive and mutation-negative patients

    NARCIS (Netherlands)

    de Laat, Joanne M.; van der Luijt, Rob B.; Pieterman, Carolina R. C.; Oostveen, Maria P.; Hermus, Ad R.; Dekkers, Olaf M.; de Herder, Wouter W.; van der Horst-Schrivers, Anouk N.; Drent, Madeleine L.; Bisschop, Peter H.; Havekes, Bas; Vriens, Menno R.; Valk, Gerlof D.


    Background: Multiple Endocrine Neoplasia type 1 (MEN1) is diagnosed when two out of the three primary MEN1-associated endocrine tumors occur in a patient. Up to 10-30 % of those patients have no mutation in the MEN1 gene. It is unclear if the phenotype and course of the disease of mutation-negative

  15. Clustered Mutation Signatures Reveal that Error-Prone DNA Repair Targets Mutations to Active Genes. (United States)

    Supek, Fran; Lehner, Ben


    Many processes can cause the same nucleotide change in a genome, making the identification of the mechanisms causing mutations a difficult challenge. Here, we show that clustered mutations provide a more precise fingerprint of mutagenic processes. Of nine clustered mutation signatures identified from >1,000 tumor genomes, three relate to variable APOBEC activity and three are associated with tobacco smoking. An additional signature matches the spectrum of translesion DNA polymerase eta (POLH). In lymphoid cells, these mutations target promoters, consistent with AID-initiated somatic hypermutation. In solid tumors, however, they are associated with UV exposure and alcohol consumption and target the H3K36me3 chromatin of active genes in a mismatch repair (MMR)-dependent manner. These regions normally have a low mutation rate because error-free MMR also targets H3K36me3 chromatin. Carcinogens and error-prone repair therefore redistribute mutations to the more important regions of the genome, contributing a substantial mutation load in many tumors, including driver mutations. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Improving the Performance of Somatic Mutation Identification by Recovering Circulating Tumor DNA Mutations. (United States)

    Fu, Yu; Jovelet, Cécile; Filleron, Thomas; Pedrero, Marion; Motté, Nelly; Boursin, Yannick; Luo, Yufei; Massard, Christophe; Campone, Mario; Levy, Christelle; Diéras, Véronique; Bachelot, Thomas; Garrabey, Julie; Soria, Jean-Charles; Lacroix, Ludovic; André, Fabrice; Lefebvre, Celine


    DNA extracted from cancer patients' whole blood may contain somatic mutations from circulating tumor DNA (ctDNA) fragments. In this study, we introduce cmDetect, a computational method for the systematic identification of ctDNA mutations using whole-exome sequencing of a cohort of tumor and corresponding peripheral whole-blood samples. Through the analysis of simulated data, we demonstrated an increase in sensitivity in calling somatic mutations by combining cmDetect to two widely used mutation callers. In a cohort of 93 breast cancer metastatic patients, cmDetect identified ctDNA mutations in 54% of the patients and recovered somatic mutations in cancer genes EGFR, PIK3CA, and TP53 We further showed that cmDetect detected ctDNA in 89% of patients with confirmed mutated cell-free tumor DNA by plasma analyses (n = 9) within 46 pan-cancer patients. Our results prompt immediate consideration of the use of this method as an additional step in somatic mutation calling using whole-exome sequencing data with blood samples as controls. Cancer Res; 76(20); 5954-61. ©2016 AACR. ©2016 American Association for Cancer Research.

  17. Familial hypercholesterolemia mutations in Petrozavodsk: no similarity to St. Petersburg mutation spectrum. (United States)

    Komarova, Tatiana Yu; Korneva, Victoria A; Kuznetsova, Tatiana Yu; Golovina, Alexandra S; Vasilyev, Vadim B; Mandelshtam, Michail Yu


    Familial hypercholesterolemia (FH) is a human monogenic disease induced by a variety of mutations with striking genetic diversity. Despite this variability recurrent mutations occur in each population studied, which allows both elucidating prevalent mutations and developing DNA diagnostic tools for the disease. Recent research of FH in St. Petersburg, Moscow and Novosibirsk (major cities in Russia) demonstrates that each megapolis has its own FH mutation spectrum sharing only small part of mutations with other populations in Russia and Europe. In order to optimize molecular-genetic diagnostic protocols for FH in Russia we studied mutation spectrum in other regions including Petrozavodsk, a smaller town in relatively close proximity to St. Petersburg. The principal method was automated detection of single-strand conformation polymorphism followed by direct PCR amplified DNA sequencing. Twelve different mutations of the low density lipoprotein (LDL) receptor gene were detected in the Petrozavodsk sample (80 patients). Out of these twelve mutations, seven have never been described before (c.192_201delinsGGACTTCA, c. 195_196insT, c. 618 T > G, c. 1340C > G, c. 1686_1693delinsT, c. 1936C > A, c. 2191delG). Other five mutations (c. 58G > A, c. 925_931del, c. 1194C > T, c. 1532 T > C, c. 1920C > T) were previously characterized elsewhere. All new mutations are considered to be a probable cause of the FH in their carriers. Direct evidence of the neutral character of c.58G > A or p. (Gly20Arg) is provided for the first time. Each pathogenic mutation was a trait of its own unique pedigree and so far has not been found in other patients. Strikingly, out of twelve mutations characterized in the Petrozavodsk sample only one mutation, c. 925_931del, has previously been found in patients from St. Petersburg and Finland (most closely located studied populations), suggesting some common roots in origin of these populations in the past or limited

  18. Tumor Mutation Burden Forecasts Outcome in Ovarian Cancer with BRCA1 or BRCA2 Mutations

    DEFF Research Database (Denmark)

    Birkbak, Nicolai Juul; Kochupurakkal, Bose; Gonzalez-Izarzugaza, Jose Maria


    Background: Increased number of single nucleotide substitutions is seen in breast and ovarian cancer genomes carrying disease-associated mutations in BRCA1 or BRCA2. The significance of these genome-wide mutations is unknown. We hypothesize genome-wide mutation burden mirrors deficiencies in DNA...... repair and is associated with treatment outcome in ovarian cancer. Methods and Results: The total number of synonymous and non-synonymous exome mutations (Nmut), and the presence of germline or somatic mutation in BRCA1 or BRCA2 (mBRCA) were extracted from whole-exome sequences of high-grade serous...... ovarian cancers from The Cancer Genome Atlas (TCGA). Cox regression and Kaplan-Meier methods were used to correlate Nmut with chemotherapy response and outcome. Higher Nmut correlated with a better response to chemotherapy after surgery. In patients with mBRCA-associated cancer, low Nmut was associated...

  19. Spectrum of mutations in RARS-T patients includes TET2 and ASXL1 mutations. (United States)

    Szpurka, Hadrian; Jankowska, Anna M; Makishima, Hideki; Bodo, Juraj; Bejanyan, Nelli; Hsi, Eric D; Sekeres, Mikkael A; Maciejewski, Jaroslaw P


    While a majority of patients with refractory anemia with ring sideroblasts and thrombocytosis harbor JAK2V617F and rarely MPLW515L, JAK2/MPL-negative cases constitute a diagnostic problem. 23 RARS-T cases were investigated applying immunohistochemical phospho-STAT5, sequencing and SNP-A-based karyotyping. Based on the association of TET2/ASXL1 mutations with MDS/MPN we studied molecular pattern of these genes. Two patients harbored ASXL1 and another 2 TET2 mutations. Phospho-STAT5 activation was present in one mutated TET2 and ASXL1 case. JAK2V617F/MPLW515L mutations were absent in TET2/ASXL1 mutants, indicating that similar clinical phenotype can be produced by various MPN-associated mutations and that additional unifying lesions may be present in RARS-T. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  20. Mutation analysis in 54 propionic acidemia patients. (United States)

    Kraus, J P; Spector, E; Venezia, S; Estes, P; Chiang, P W; Creadon-Swindell, G; Müllerleile, S; de Silva, L; Barth, M; Walter, M; Walter, K; Meissner, T; Lindner, M; Ensenauer, R; Santer, R; Bodamer, O A; Baumgartner, M R; Brunner-Krainz, M; Karall, D; Haase, C; Knerr, I; Marquardt, T; Hennermann, J B; Steinfeld, R; Beblo, S; Koch, H G; Konstantopoulou, V; Scholl-Bürgi, S; van Teeffelen-Heithoff, A; Suormala, T; Ugarte, M; Sperl, W; Superti-Furga, A; Schwab, K O; Grünert, S C; Sass, J O


    Deficiency of propionyl CoA carboxylase (PCC), a dodecamer of alpha and beta subunits, causes inherited propionic acidemia. We have studied, at the molecular level, PCC in 54 patients from 48 families comprised of 96 independent alleles. These patients of various ethnic backgrounds came from research centers and hospitals in Germany, Austria and Switzerland. The thorough clinical characterization of these patients was described in the accompanying paper (Grünert et al. 2012). In all 54 patients, many of whom originated from consanguineous families, the entire PCCB gene was examined by genomic DNA sequencing and in 39 individuals the PCCA gene was also studied. In three patients we found mutations in both PCC genes. In addition, in many patients RT-PCR analysis of lymphoblast RNA, lymphoblast enzyme assays, and expression of new mutations in E.coli were carried out. Eight new and eight previously detected mutations were identified in the PCCA gene while 15 new and 13 previously detected mutations were found in the PCCB gene. One missense mutation, p.V288I in the PCCB gene, when expressed in E.coli, yielded 134% of control activity and was consequently classified as a polymorphism in the coding region. Numerous new intronic polymorphisms in both PCC genes were identified. This study adds a considerable amount of new molecular data to the studies of this disease.

  1. GREMLIN 2 Mutations and Dental Anomalies. (United States)

    Kantaputra, P N; Kaewgahya, M; Hatsadaloi, A; Vogel, P; Kawasaki, K; Ohazama, A; Ketudat Cairns, J R


    Isolated or nonsyndromic tooth agenesis or hypodontia is the most common human malformation. It has been associated with mutations in MSX1, PAX9, EDA, AXIN2, EDAR, EDARADD, and WNT10A. GREMLIN 2 (GREM2) is a strong bone morphogenetic protein (BMP) antagonist that is known to regulate BMPs in embryogenesis and tissue development. Bmp4 has been shown to have a role in tooth development. Grem2(-/-) mice have small, malformed maxillary and mandibular incisors, indicating that Grem2 has important roles in normal tooth development. Here, we demonstrate for the first time that GREM2 mutations are associated with human malformations, which include isolated tooth agenesis, microdontia, short tooth roots, taurodontism, sparse and slow-growing hair, and dry and itchy skin. We sequenced WNT10A, WNT10B, MSX1, EDA, EDAR, EDARADD, AXIN2, and PAX9 in all 7 patients to rule out the effects of other ectodermal dysplasias and other tooth-related genes and did not find mutations in any of them. GREM2 mutations exhibit variable expressivity even within the same families. The inheritance is autosomal dominant with incomplete penetrance. The expression of Grem2 during the early development of mouse teeth and hair follicles and the evaluation of the likely effects of the mutations on the protein structure substantiate these new findings. © International & American Associations for Dental Research 2015.

  2. BRCA1 mutations in Brazilian patients

    Directory of Open Access Journals (Sweden)

    Juliano Javert Lourenço


    Full Text Available BRCA1 mutations are known to be responsible for the majority of hereditary breast and ovarian cancers in women with early onset and a family history of the disease. In this paper we present a mutational survey conducted in 47 Brazilian patients with breast/ovarian cancer, selected based on age at diagnosis, family history, tumor laterality, and presence of breast cancer in male patients. All 22 coding exons and intron-exon junctions were sequenced. Constitutional mutations were found in seven families, consisting of one insertion (insC5382 in exon 20 (four patients, one four base-pair deletion (3450-3453delCAAG in exon 11 resulting in a premature stop codon (one patient, one transition (IVS17+2T> C in intron 17 affecting a mRNA splicing site (one patient, and a C> T transition resulting in a stop-codon (Q1135X in exon 11 (one patient. The identification of these mutations which are associated to hereditary breast and ovarian cancers will contribute to the characterization of the mutational spectrum of BRCA1 and to the improvement of genetic counseling for familial breast/ovarian cancer patients in Brazil.

  3. Immunohistochemical Detections of EGFR Mutations in NSCLC

    Directory of Open Access Journals (Sweden)

    Chang LIU


    Full Text Available In recent years, it has been well known that non-small cell lung cancer (NSCLC patients with mutations of epidermal growth factor receptor (EGFR response better to EGFR-tyrosine kinase inhibitor treatment. Although DNA-based assays (e.g. DNA sequencing are the most frequently used and a relatively reliable method to detect EGFR mutations, they are complex, time-consuming and relatively expensive for routine use in clinical laboratories, besides they require high quality tumor samples. In contrast, the immunohistochemistry (IHC methods make up fully for the above shortcomings and can serve as screening tests for EGFR mutations. However, there are many factors that can influence the results of IHC methods, such as different staining procedures, different antigen retrieval solutions and different sets of criteria, etc. Thus the IHC methods for detecting EGFR mutations have not been widely used in clinic and only in the research stage. This article reviews the use of IHC methods by different researchers and further discusses how to make the IHC methods work best for the detection of EGFR mutations.

  4. Expanding CEP290 mutational spectrum in ciliopathies. (United States)

    Travaglini, Lorena; Brancati, Francesco; Attie-Bitach, Tania; Audollent, Sophie; Bertini, Enrico; Kaplan, Josseline; Perrault, Isabelle; Iannicelli, Miriam; Mancuso, Brunella; Rigoli, Luciana; Rozet, Jean-Michel; Swistun, Dominika; Tolentino, Jerlyn; Dallapiccola, Bruno; Gleeson, Joseph G; Valente, Enza Maria; Zankl, A; Leventer, R; Grattan-Smith, P; Janecke, A; D'Hooghe, M; Sznajer, Y; Van Coster, R; Demerleir, L; Dias, K; Moco, C; Moreira, A; Kim, C Ae; Maegawa, G; Petkovic, D; Abdel-Salam, G M H; Abdel-Aleem, A; Zaki, M S; Marti, I; Quijano-Roy, S; Sigaudy, S; de Lonlay, P; Romano, S; Touraine, R; Koenig, M; Lagier-Tourenne, C; Messer, J; Collignon, P; Wolf, N; Philippi, H; Kitsiou Tzeli, S; Halldorsson, S; Johannsdottir, J; Ludvigsson, P; Phadke, S R; Udani, V; Stuart, B; Magee, A; Lev, D; Michelson, M; Ben-Zeev, B; Fischetto, R; Benedicenti, F; Stanzial, F; Borgatti, R; Accorsi, P; Battaglia, S; Fazzi, E; Giordano, L; Pinelli, L; Boccone, L; Bigoni, S; Ferlini, A; Donati, M A; Caridi, G; Divizia, M T; Faravelli, F; Ghiggeri, G; Pessagno, A; Briguglio, M; Briuglia, S; Salpietro, C D; Tortorella, G; Adami, A; Castorina, P; Lalatta, F; Marra, G; Riva, D; Scelsa, B; Spaccini, L; Uziel, G; Del Giudice, E; Laverda, A M; Ludwig, K; Permunian, A; Suppiej, A; Signorini, S; Uggetti, C; Battini, R; Di Giacomo, M; Cilio, M R; Di Sabato, M L; Leuzzi, V; Parisi, P; Pollazzon, M; Silengo, M; De Vescovi, R; Greco, D; Romano, C; Cazzagon, M; Simonati, A; Al-Tawari, A A; Bastaki, L; Mégarbané, A; Sabolic Avramovska, V; de Jong, M M; Stromme, P; Koul, R; Rajab, A; Azam, M; Barbot, C; Martorell Sampol, L; Rodriguez, B; Pascual-Castroviejo, I; Teber, S; Anlar, B; Comu, S; Karaca, E; Kayserili, H; Yüksel, A; Akcakus, M; Al Gazali, L; Sztriha, L; Nicholl, D; Woods, C G; Bennett, C; Hurst, J; Sheridan, E; Barnicoat, A; Hennekam, R; Lees, M; Blair, E; Bernes, S; Sanchez, H; Clark, A E; DeMarco, E; Donahue, C; Sherr, E; Hahn, J; Sanger, T D; Gallager, T E; Dobyns, W B; Daugherty, C; Krishnamoorthy, K S; Sarco, D; Walsh, C A; McKanna, T; Milisa, J; Chung, W K; De Vivo, D C; Raynes, H; Schubert, R; Seward, A; Brooks, D G; Goldstein, A; Caldwell, J; Finsecke, E; Maria, B L; Holden, K; Cruse, R P; Swoboda, K J; Viskochil, D


    Ciliopathies are an expanding group of rare conditions characterized by multiorgan involvement, that are caused by mutations in genes encoding for proteins of the primary cilium or its apparatus. Among these genes, CEP290 bears an intriguing allelic spectrum, being commonly mutated in Joubert syndrome and related disorders (JSRD), Meckel syndrome (MKS), Senior-Loken syndrome and isolated Leber congenital amaurosis (LCA). Although these conditions are recessively inherited, in a subset of patients only one CEP290 mutation could be detected. To assess whether genomic rearrangements involving the CEP290 gene could represent a possible mutational mechanism in these cases, exon dosage analysis on genomic DNA was performed in two groups of CEP290 heterozygous patients, including five JSRD/MKS cases and four LCA, respectively. In one JSRD patient, we identified a large heterozygous deletion encompassing CEP290 C-terminus that resulted in marked reduction of mRNA expression. No copy number alterations were identified in the remaining probands. The present work expands the CEP290 genotypic spectrum to include multiexon deletions. Although this mechanism does not appear to be frequent, screening for genomic rearrangements should be considered in patients in whom a single CEP290 mutated allele was identified.

  5. BRAF mutation in hairy cell leukemia

    Directory of Open Access Journals (Sweden)

    Ahmad Ahmadzadeh


    Full Text Available BRAF is a serine/threonine kinase with a regulatory role in the mitogen-activated protein kinase (MAPK signaling pathway. A mutation in the RAF gene, especially in BRAF protein, leads to an increased stimulation of this cascade, causing uncontrolled cell division and development of malignancy. Several mutations have been observed in the gene coding for this protein in a variety of human malignancies, including hairy cell leukemia (HCL. BRAF V600E is the most common mutation reported in exon15 of BRAF, which is observed in almost all cases of classic HCL, but it is negative in other B-cell malignancies, including the HCL variant. Therefore it can be used as a marker to differentiate between these B-cell disorders. We also discuss the interaction between miRNAs and signaling pathways, including MAPK, in HCL. When this mutation is present, the use of BRAF protein inhibitors may represent an effective treatment. In this review we have evaluated the role of the mutation of the BRAF gene in the pathogenesis and progression of HCL.

  6. Oncogene mutation profiling reveals poor prognosis associated with FGFR1/3 mutation in liposarcoma. (United States)

    Li, Chengfang; Shen, Yaoyuan; Ren, Yan; Liu, Wei; Li, Man; Liang, Weihua; Liu, Chunxia; Li, Feng


    Liposarcoma (LPS) is one of the most prevalent soft tissue sarcomas. LPS shows a poor response to radiation and chemotherapy. The causes of death in patients with LPS include locally recurrent and metastatic disease. We sought to examine novel gene mutations and pathways in primary and matched recurrent LPSs to identify potential therapeutic targets. We conducted a high-throughput analysis of 238 known mutations in 19 oncogenes using Sequenom MassARRAY technology. Nucleic acids were extracted from 19 primary and recurrent LPS samples, encompassing 9 dedifferentiated LPSs (DDLPS), 9 myxoid/round cell LPSs, and 1 pleomorphic LPS. Mutation screening revealed missense mutations in 21.1% (4/19) of the LPS specimens, including 4 different genes (FGFR1, FGFR3, PIK3CA, and KIT). Based on histologic subtypes, 22.2% DDLPS (2/9) and 22.2% myxoid cell LPS (2/9) contained gene mutations. Specifically, 3 (23.1%) of 13 primary tumors harbored mutations. Furthermore, although gene mutations were identified in 1 (11.1%) of 9 recurrent LPS samples, the difference between the primary and the recurrence was not statistically significant. Analysis of patient survival data indicated that patients harboring FGFR1/3 mutations experienced reduced overall survival (P<.05). Despite the limited number of samples, our findings provide the first evidence of FGFR1/3 mutations in DDLPS, which were associated with poor clinical outcomes. The FGFR pathway may play an important role in the development and progression of DDLPS and warrants further investigation; moreover, PIK3CA mutation is a common event (11.1%) in myxoid cell LPS. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. HER2 mutations in lung adenocarcinomas: A report from the Lung Cancer Mutation Consortium. (United States)

    Pillai, Rathi N; Behera, Madhusmita; Berry, Lynne D; Rossi, Mike R; Kris, Mark G; Johnson, Bruce E; Bunn, Paul A; Ramalingam, Suresh S; Khuri, Fadlo R


    Human epidermal growth factor receptor 2 (HER2) mutations have been reported in lung adenocarcinomas. Herein, the authors describe the prevalence, clinical features, and outcomes associated with HER2 mutations in 1007 patients in the Lung Cancer Mutation Consortium (LCMC). Patients with advanced-stage lung adenocarcinomas were enrolled to the LCMC. Tumor specimens were assessed for diagnosis and adequacy; multiplexed genotyping was performed in Clinical Laboratory Improvement Amendments (CLIA)-certified laboratories to examine 10 oncogenic drivers. The LCMC database was queried for patients with HER2 mutations to access demographic data, treatment history, and vital status. An exploratory analysis was performed to evaluate the survival of patients with HER2 mutations who were treated with HER2-directed therapies. A total of 920 patients were tested for HER2 mutations; 24 patients (3%) harbored exon 20 insertion mutations (95% confidence interval, 2%-4%). One patient had a concurrent mesenchymal-epithelial transition factor (MET) amplification. The median age of the patients was 62 years, with a slight predominance of females over males (14 females vs 10 males). The majority of the patients were never-smokers (71%) and presented with advanced disease at the time of diagnosis. The median survival for patients who received HER2-targeted therapies (12 patients) was 2.1 years compared with 1.4 years for those who did not (12 patients) (P = .48). Patients with HER2 mutations were found to have inferior survival compared with the rest of the LCMC cohort with other mutations: the median survival was 3.5 years in the LCMC population receiving targeted therapy and 2.4 years for patients not receiving targeted therapy. HER2 mutations were detected in 3% of patients with lung adenocarcinoma in the LCMC. HER2-directed therapies should be investigated in this subgroup of patients. Cancer 2017;123:4099-4105. © 2017 American Cancer Society. © 2017 American Cancer Society.

  8. Mutation induction in synchronous hamster cells

    Energy Technology Data Exchange (ETDEWEB)

    Aebersold, P.M.


    Mutagenesis of synchronous Mutahinese hamster cells by 5-bromodeoxyuridine (BUdR) shows pronounced cell cycle dependency. Resistance to 6-thioguanine (6-TG) and ouabain are induced maximally by BUdR at different times early in the DNA synthesis period, suggesting that the genes coding for hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and the (Na/sup +/K/sup +/)-associated ATPase of the plasma membrane are replicated early in the DNA synthesis period. Although BUdR induces mutations in specific genes only when present during their replication, the rate of mutation induction is not linearly related to the amount of BUdR incorporated into DNA. The data show a BUdR concentration threshold for mutation induction, suggesting that BUdR exerts some deterimental allosteric effect on DNA synthesis enzymes.

  9. Selection-Mutation Dynamics of Signaling Games

    Directory of Open Access Journals (Sweden)

    Josef Hofbauer


    Full Text Available We study the structure of the rest points of signaling games and their dynamic behavior under selection-mutation dynamics by taking the case of three signals as our canonical example. Many rest points of the replicator dynamics of signaling games are not isolated and, therefore, not robust under perturbations. However, some of them attract open sets of initial conditions. We prove the existence of certain rest points of the selection-mutation dynamics close to Nash equilibria of the signaling game and show that all but the perturbed rest points close to strict Nash equilibria are dynamically unstable. This is an important result for the evolution of signaling behavior, since it shows that the second-order forces that are governed by mutation can increase the chances of successful signaling.

  10. Mutations and Antimutagens in Emergency Medicine

    Directory of Open Access Journals (Sweden)

    V. V. Moroz


    Full Text Available Among other negative sequels, hypoxia that is the leading cause of all critical conditions increases the frequency of cell mutations in the patient. Unfortunately, we do not know whether there are available special studies analyzing the frequency of mutations in the germ cells of experimental animals or humans. But those in the somatic cells were reported in various publications more than 30 years ago. Specifically, such phenomena have been described in acute lung injuries and myocardial infarction in both rats and man. But these studies have been sporadic. And the increase in the frequency of somatic mutation affects the incidence of apoptosis, the change in the pattern of immunological processes and, possibly, even the factors of carcinogenesis. Mutagenetic processes can be managed, by modifying their frequency with antimuta-gens. 

  11. Mutations and their use in insect control. (United States)

    Robinson, Alan S


    Traditional chemically based methods for insect control have been shown to have serious limitations, and many alternative approaches have been developed and evaluated, including those based on the use of different types of mutation. The mutagenic action of ionizing radiation was well known in the field of genetics long before it was realized by entomologists that it might be used to induce dominant lethal mutations in insects, which, when released, could sterilize wild female insects. The use of radiation to induce dominant lethal mutations in the sterile insect technique (SIT) is now a major component of many large and successful programs for pest suppression and eradication. Adult insects, and their different developmental stages, differ in their sensitivity to the induction of dominant lethal mutations, and care has to be taken to identify the appropriate dose of radiation that produces the required level of sterility without impairing the overall fitness of the released insect. Sterility can also be introduced into populations through genetic mechanisms, including translocations, hybrid incompatibility, and inherited sterility in Lepidoptera. The latter phenomenon is due to the fact that this group of insects has holokinetic chromosomes. Specific types of mutations can also be used to make improvements to the SIT, especially for the development of strains for the production of only male insects for sterilization and release. These strains utilize male translocations and a variety of selectable mutations, either conditional or visible, so that at some stage of development, the males can be separated from the females. In one major insect pest, Ceratitis capitata, these strains are used routinely in large operational programs. This review summarizes these developments, including the possible future use of transgenic technology in pest control.

  12. Mutation induction by ion beams in arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment


    An investigation was made on characteristics of ion beams for the biological effects and the induction of mutation using Arabidopsis plant as a model plant for the molecular genetics. Here, the characteristics of mutation at the molecular level as well as new mutants induced by ion beams were described. The ast and sep1 were obtained from the offspring of 1488 carbon ion-irradiated seeds respectively. The uvi1-uvi4 mutants were also induced from 1280 M{sub 1} lines. Thus, ion beams can induce not only known mutants such as tt, gl and hy but also novel mutants with high frequency. Even in the tt phenotype, two new mutant loci other than known loci were found. In chrysanthemum, several kinds of single, complex or stripped flower-color mutants that have been never induced by {gamma}irradiation, indicating that ion beams could produce a variety of mutants with the same phenotype. In conclusion, ion beams for the mutation induction are characterized by 1) to induce mutants with high frequency, 2) to show broad mutation spectrum and 3) to produce novel mutants. For these reasons, chemical mutagens such as EMS and low LET ionizing radiation such as X-rays and {gamma}-rays will predominantly induce many but small modifications or DNA damages on the DNA strands. As the result, several point mutations will be produced on the genome. On the contrary, ion beams as a high LET ionizing radiation will not cause so many but large and irreparable DNA damage locally, resulting in production of limited number of null mutation. (M.N.)

  13. Deciphering Signatures of Mutational Processes Operative in Human Cancer (United States)

    Alexandrov, Ludmil B.; Nik-Zainal, Serena; Wedge, David C.; Campbell, Peter J.; Stratton, Michael R.


    Summary The genome of a cancer cell carries somatic mutations that are the cumulative consequences of the DNA damage and repair processes operative during the cellular lineage between the fertilized egg and the cancer cell. Remarkably, these mutational processes are poorly characterized. Global sequencing initiatives are yielding catalogs of somatic mutations from thousands of cancers, thus providing the unique opportunity to decipher the signatures of mutational processes operative in human cancer. However, until now there have been no theoretical models describing the signatures of mutational processes operative in cancer genomes and no systematic computational approaches are available to decipher these mutational signatures. Here, by modeling mutational processes as a blind source separation problem, we introduce a computational framework that effectively addresses these questions. Our approach provides a basis for characterizing mutational signatures from cancer-derived somatic mutational catalogs, paving the way to insights into the pathogenetic mechanism underlying all cancers. PMID:23318258

  14. Driver KIT mutations in melanoma cluster in four hotspots. (United States)

    Dumaz, Nicolas; André, Jocelyne; Sadoux, Aurélie; Laugier, Florence; Podgorniak, Marie Pierre; Mourah, Samia; Lebbé, Céleste


    There has been a great deal of interest in understanding the role of KIT in melanoma since the discovery of KIT mutations in a subset of melanoma. Although a significant proportion of these melanomas respond to KIT inhibitors, the presence of a KIT mutation does not guarantee a response to KIT inhibitors. Because recent data seem to indicate that only melanoma with specific KIT mutations respond to KIT inhibitors, we investigated which KIT mutations are driver mutations in melanoma and are therefore therapeutically relevant. We established that 70% of KIT mutations in melanoma are located in four hotspots (L576, K642, W557-V560, and D816-A829) and that these mutations are oncogenic in melanocytes and are bona-fide driver mutations. Testing for KIT mutations should therefore concentrate on these four hotspots, which can be targeted therapeutically.

  15. Mutations found in the Danish population causing Hereditary Hemorrhagic Telangiectasia

    DEFF Research Database (Denmark)

    Tørring, Pernille M; Brusgaard, Klaus


    been performing genetic screening of patients and relatives with HHT. The molecular genetic screening serves dual purposes, a) as part of the clinical management as genotype/phenotype correlations exists, b) to identify asymptomatic family members. Materials and Methods Inclusion of patient’s who were....... Results In 61 families we found mutations in either ENG (N=35) or ACVLR1 (N=26). In ENG a total of 22 different mutations were found 16 was unreported. In ACVLR1 24 different mutations were found 13 was unreported. The mutations were mainly of a familial character all though in ENG a single mutation...... is present in 11 families and 2 mutations are represented in 2 families. Likewise in ACVLR1 2 mutations was found in 2 different families. I ENG 1 and in ACVLR1 3 families had major deletions found by MLPA. No mutations were found in MADH4. Conclusion The majority of mutations found during clinical genetic...

  16. KIT mutation analysis in mast cell neoplasms

    DEFF Research Database (Denmark)

    Arock, M; Sotlar, K; Akin, C


    Although acquired mutations in KIT are commonly detected in various categories of mastocytosis, the methodologies applied to detect and quantify the mutant type and allele burden in various cells and tissues are poorly defined. We here propose a consensus on methodologies used to detect KIT...... mutations in patients with mastocytosis at diagnosis and during follow-up with sufficient precision and sensitivity in daily practice. In addition, we provide recommendations for sampling and storage of diagnostic material as well as a robust diagnostic algorithm. Using highly sensitive assays, KIT D816V...

  17. On spatial mutation-selection models

    Energy Technology Data Exchange (ETDEWEB)

    Kondratiev, Yuri, E-mail: [Fakultät für Mathematik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld (Germany); Kutoviy, Oleksandr, E-mail:, E-mail: [Fakultät für Mathematik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld (Germany); Department of Mathematics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Minlos, Robert, E-mail:; Pirogov, Sergey, E-mail: [IITP, RAS, Bolshoi Karetnyi 19, Moscow (Russian Federation)


    We discuss the selection procedure in the framework of mutation models. We study the regulation for stochastically developing systems based on a transformation of the initial Markov process which includes a cost functional. The transformation of initial Markov process by cost functional has an analytic realization in terms of a Kimura-Maruyama type equation for the time evolution of states or in terms of the corresponding Feynman-Kac formula on the path space. The state evolution of the system including the limiting behavior is studied for two types of mutation-selection models.

  18. Towards linked open gene mutations data (United States)


    Background With the advent of high-throughput technologies, a great wealth of variation data is being produced. Such information may constitute the basis for correlation analyses between genotypes and phenotypes and, in the future, for personalized medicine. Several databases on gene variation exist, but this kind of information is still scarce in the Semantic Web framework. In this paper, we discuss issues related to the integration of mutation data in the Linked Open Data infrastructure, part of the Semantic Web framework. We present the development of a mapping from the IARC TP53 Mutation database to RDF and the implementation of servers publishing this data. Methods A version of the IARC TP53 Mutation database implemented in a relational database was used as first test set. Automatic mappings to RDF were first created by using D2RQ and later manually refined by introducing concepts and properties from domain vocabularies and ontologies, as well as links to Linked Open Data implementations of various systems of biomedical interest. Since D2RQ query performances are lower than those that can be achieved by using an RDF archive, generated data was also loaded into a dedicated system based on tools from the Jena software suite. Results We have implemented a D2RQ Server for TP53 mutation data, providing data on a subset of the IARC database, including gene variations, somatic mutations, and bibliographic references. The server allows to browse the RDF graph by using links both between classes and to external systems. An alternative interface offers improved performances for SPARQL queries. The resulting data can be explored by using any Semantic Web browser or application. Conclusions This has been the first case of a mutation database exposed as Linked Data. A revised version of our prototype, including further concepts and IARC TP53 Mutation database data sets, is under development. The publication of variation information as Linked Data opens new perspectives

  19. Clinicopathological characteristics and mutation profiling in primary cutaneous melanoma. (United States)

    Yaman, Banu; Akalin, Taner; Kandiloğlu, Gülşen


    The incidence of mutations in malignant melanoma varies remarkably according to the subtype of melanoma, and this in itself is affected by racial and geographical factors. Studies screening melanoma case series for different types of mutations are relatively rare. The authors analyzed the frequency of various somatic point mutations of 10 genes in 106 primary cutaneous melanoma cases. The mutations (BRAF, NRAS, KIT, CDKN2A, KRAS, HRAS, PIK3CA, STK11, GNAQ, CTNNB1) were evaluated with real-time PCR-based PCR-Array through allele-specific amplification, and the results were correlated with various clinicopathological characteristics. Mutations were found in 64.2% of the melanomas overall. BRAF (42.5%), NRAS (15.1%), and CDKN2A (13.2%) were the 3 most common mutations. BRAF and NRAS mutations were more frequent in nodular and superficial spreading melanomas (P < 0.001). Associations with BRAF mutation were as follows: male gender [odds ratio (OR) = 2.4], younger age (OR = 2.7), superficial spreading (OR = 15.6) and nodular melanoma (OR = 9.5), trunk localization (OR = 6.3), and intermittent sun exposure (OR = 4.6). A considerable percentage of V600K (44.4%) mutations were found among the BRAF mutations, whereas KIT mutations (3.8%) were less frequent. Multiple mutations were detected in 13.2% of the melanomas. The most common co-occurrences were in the BRAF, NRAS, and CDKN2A genes. The authors analyzed 10 somatic mutations in the main subtypes of primary cutaneous melanomas from the western region of Turkey. Mutations were found in 64.2% of the melanomas overall. The most common mutations were in the BRAF and NRAS genes. In addition to other less common mutations, a notable number of multiple mutations were encountered. The multiplicity and concurrence of mutations in this study may provide further study areas for personalized targeted therapy.

  20. Confirmation of the mitochondrial ND1 gene mutation G3635A as a primary LHON mutation. (United States)

    Yang, Juhua; Zhu, Yihua; Tong, Yi; Chen, Lu; Liu, Lijuan; Zhang, Zhiqiang; Wang, Xiaoyan; Huang, Dinggou; Qiu, Wentong; Zhuang, Shuliu; Ma, Xu


    We report the clinical and genetic characterization of two Chinese LHON families who do not carry the primary LHON-mutations. Mitochondrial genome sequence analysis revealed the presence of a homoplasmic ND1 G3635A mutation in both families. In Family LHON-001, 31 other variants belonging to the East Asian haplogroup R11a were identified and in Family LHON-019, 37 other variants belonging to the East Asian haplogroup D4g were determined. The ND1 G3635A mutation changes the conversed serine110 residue to asparagine. This mutation has been previously described in a single Russian LHON family and has been suggested to contribute to increased LHON expressivity. In addition, a mutation in cytochrome c oxidase subunit II at C7868T (COII/L95F) may act in synergy with G3635A, increasing LHON expressivity in Family LHON-001, which had a higher level of LHON penetrance than Family LHON-019. In summary, the G3635A mutation is confirmed as a rare primary pathogenic mutation for LHON.

  1. Mutation distributions and clinical correlations of PIK3CA gene mutations in breast cancer. (United States)

    Dirican, Ebubekir; Akkiprik, Mustafa; Özer, Ayşe


    Breast cancer (BCa) is the most common cancer and the second cause of death among women. Phosphoinositide 3-kinase (PI3K) signaling pathway has a crucial role in the cellular processes such as cell survival, growth, division, and motility. Moreover, oncogenic mutations in the PI3K pathway generally involve the activation phosphatidylinositol-4,5-bisphosphate 3-kinase-catalytic subunit alpha (PIK3CA) mutation which has been identified in numerous BCa subtypes. In this review, correlations between PIK3CA mutations and their clinicopathological parameters on BCa will be described. It is reported that PIK3CA mutations which have been localized mostly on exon 9 and 20 hot spots are detected 25-40 % in BCa. This relatively high frequency can offer an advantage for choosing the best treatment options for BCa. PIK3CA mutations may be used as biomarkers and have been major focus of drug development in cancer with the first clinical trials of PI3K pathway inhibitors currently in progress. Screening of PIK3CA gene mutations might be useful genetic tests for targeted therapeutics or diagnosis. Increasing data about PIK3CA mutations and its clinical correlations with BCa will help to introduce new clinical applications in the near future.

  2. Macular corneal dystrophy: mutational spectrum in German patients, novel mutations and therapeutic options. (United States)

    Gruenauer-Kloevekorn, Claudia; Braeutigam, Saskia; Heinritz, Wolfram; Froster, Ursula G; Duncker, Gernot I W


    The objective of this study was to investigate genotype-phenotype correlations, the consequences for surgical treatment, and the therapeutical options in patients with macular corneal dystrophy (MCD). We investigated MCD genotype by using polymerase chain reaction followed by direct sequencing in one family and four patients with MCD. Results were confirmed by restriction analysis. Clinical phenotypes, histopathological findings, and therapeutical proceedings of each patient were reported and compared with the molecular genetic results. Five mutations, four missense mutations, and one frameshift mutation, from which three were novel, and one single-nucleotide polymorphism, were identified within the coding region of the CHST6 gene. In three patients, two with a homozygous mutation within the start codon (Met1Leu) and one with a heterozygous mutation (Leu200Arg) and a polymorphism (Arg162Gly), with irregular corneal surface and recurrent erosions a phototherapeutic keratectomy lead to a transient success. An additional fitting of rigid gas permeable contact lenses in one patient could further improve irregular astigmatism. In two patients, one with a frameshift mutation (1734_1735delTG; Arg211Gln) and one with two compound heterozygous mutations (Leu200Arg; Leu173Phe) and an additional polymorphism (Arg162Gly) a penetrating keratoplasty improved BCVA without any recurrence of the opacities within the follow-up time. Different genotypes imply several phenotypes, which influence therapeutical proceedings in MCD patients. Our study shows the wide range of diagnostic findings and therapeutical options in patients suffering from macular corneal dystrophy depending on the genotype.

  3. Molecular evaluation of a novel missense mutation & an insertional truncating mutation in SUMF1 gene

    Directory of Open Access Journals (Sweden)

    Udhaya H Kotecha


    Full Text Available Background & objectives: Multiple suphphatase deficiency (MSD is an autosomal recessive disorder affecting the post translational activation of all enzymes of the sulphatase family. To date, approximately 30 different mutations have been identified in the causative gene, sulfatase modifying factor 1 (SUMF1. We describe here the mutation analysis of a case of MSD. Methods: The proband was a four year old boy with developmental delay followed by neuroregression. He had coarse facies, appendicular hypertonia, truncal ataxia and ichthyosis limited to both lower limbs. Radiographs showed dysostosis multiplex. Clinical suspicion of MSD was confirmed by enzyme analysis of four enzymes of the sulphatase group. Results: The patient was compound heterozygote for a c.451A>G (p.K151E substitution in exon 3 and a single base insertion mutation (c.690_691 InsT in exon 5 in the SUMF1 gene. The bioinformatic analysis of the missense mutation revealed no apparent effect on the overall structure. However, the mutated 151-amino acid residue was found to be adjacent to the substrate binding and the active site residues, thereby affecting the substrate binding and/or catalytic activity, resulting in almost complete loss of enzyme function. Conclusions: The two mutations identified in the present case were novel. This is perhaps the first report of an insertion mutation in SUMF1 causing premature truncation of the protein.

  4. Molecular evaluation of a novel missense mutation & an insertional truncating mutation in SUMF1 gene. (United States)

    Kotecha, Udhaya H; Movva, Sireesha; Sharma, Deepak; Verma, Jyotsna; Puri, Ratna Dua; Verma, Ishwar Chander


    Multiple suphphatase deficiency (MSD) is an autosomal recessive disorder affecting the post translational activation of all enzymes of the sulphatase family. To date, approximately 30 different mutations have been identified in the causative gene, sulfatase modifying factor 1 (SUMF1). We describe here the mutation analysis of a case of MSD. The proband was a four year old boy with developmental delay followed by neuroregression. He had coarse facies, appendicular hypertonia, truncal ataxia and ichthyosis limited to both lower limbs. Radiographs showed dysostosis multiplex. Clinical suspicion of MSD was confirmed by enzyme analysis of four enzymes of the sulphatase group. The patient was compound heterozygote for a c.451A>G (p.K151E) substitution in exon 3 and a single base insertion mutation (c.690_691 InsT) in exon 5 in the SUMF1 gene. The bioinformatic analysis of the missense mutation revealed no apparent effect on the overall structure. However, the mutated 151-amino acid residue was found to be adjacent to the substrate binding and the active site residues, thereby affecting the substrate binding and/or catalytic activity, resulting in almost complete loss of enzyme function. The two mutations identified in the present case were novel. This is perhaps the first report of an insertion mutation in SUMF1 causing premature truncation of the protein.

  5. Revertant mutation releases confined lethal mutation, opening Pandora's box: a novel genetic pathogenesis.

    Directory of Open Access Journals (Sweden)

    Yasushi Ogawa


    Full Text Available When two mutations, one dominant pathogenic and the other "confining" nonsense, coexist in the same allele, theoretically, reversion of the latter may elicit a disease, like the opening of Pandora's box. However, cases of this hypothetical pathogenic mechanism have never been reported. We describe a lethal form of keratitis-ichthyosis-deafness (KID syndrome caused by the reversion of the GJB2 nonsense mutation p.Tyr136X that would otherwise have confined the effect of another dominant lethal mutation, p.Gly45Glu, in the same allele. The patient's mother had the identical misssense mutation which was confined by the nonsense mutation. The biological relationship between the parents and the child was confirmed by genotyping of 15 short tandem repeat loci. Haplotype analysis using 40 SNPs spanning the >39 kbp region surrounding the GJB2 gene and an extended SNP microarray analysis spanning 83,483 SNPs throughout chromosome 13 in the family showed that an allelic recombination event involving the maternal allele carrying the mutations generated the pathogenic allele unique to the patient, although the possibility of coincidental accumulation of spontaneous point mutations cannot be completely excluded. Previous reports and our mutation screening support that p.Gly45Glu is in complete linkage disequilibrium with p.Tyr136X in the Japanese population. Estimated from statisitics in the literature, there may be approximately 11,000 p.Gly45Glu carriers in the Japanese population who have this second-site confining mutation, which acts as natural genetic protection from the lethal disease. The reversion-triggered onset of the disesase shown in this study is a previously unreported genetic pathogenesis based on Mendelian inheritance.

  6. Tumor mutation burden forecasts outcome in ovarian cancer with BRCA1 or BRCA2 mutations. (United States)

    Birkbak, Nicolai Juul; Kochupurakkal, Bose; Izarzugaza, Jose M G; Eklund, Aron C; Li, Yang; Liu, Joyce; Szallasi, Zoltan; Matulonis, Ursula A; Richardson, Andrea L; Iglehart, J Dirk; Wang, Zhigang C


    Increased number of single nucleotide substitutions is seen in breast and ovarian cancer genomes carrying disease-associated mutations in BRCA1 or BRCA2. The significance of these genome-wide mutations is unknown. We hypothesize genome-wide mutation burden mirrors deficiencies in DNA repair and is associated with treatment outcome in ovarian cancer. The total number of synonymous and non-synonymous exome mutations (Nmut), and the presence of germline or somatic mutation in BRCA1 or BRCA2 (mBRCA) were extracted from whole-exome sequences of high-grade serous ovarian cancers from The Cancer Genome Atlas (TCGA). Cox regression and Kaplan-Meier methods were used to correlate Nmut with chemotherapy response and outcome. Higher Nmut correlated with a better response to chemotherapy after surgery. In patients with mBRCA-associated cancer, low Nmut was associated with shorter progression-free survival (PFS) and overall survival (OS), independent of other prognostic factors in multivariate analysis. Patients with mBRCA-associated cancers and a high Nmut had remarkably favorable PFS and OS. The association with survival was similar in cancers with either BRCA1 or BRCA2 mutations. In cancers with wild-type BRCA, tumor Nmut was associated with treatment response in patients with no residual disease after surgery. Tumor Nmut was associated with treatment response and with both PFS and OS in patients with high-grade serous ovarian cancer carrying BRCA1 or BRCA2 mutations. In the TCGA cohort, low Nmut predicted resistance to chemotherapy, and for shorter PFS and OS, while high Nmut forecasts a remarkably favorable outcome in mBRCA-associated ovarian cancer. Our observations suggest that the total mutation burden coupled with BRCA1 or BRCA2 mutations in ovarian cancer is a genomic marker of prognosis and predictor of treatment response. This marker may reflect the degree of deficiency in BRCA-mediated pathways, or the extent of compensation for the deficiency by alternative

  7. Biallelic BRCA2 Mutations Shape the Somatic Mutational Landscape of Aggressive Prostate Tumors. (United States)

    Decker, Brennan; Karyadi, Danielle M; Davis, Brian W; Karlins, Eric; Tillmans, Lori S; Stanford, Janet L; Thibodeau, Stephen N; Ostrander, Elaine A


    To identify clinically important molecular subtypes of prostate cancer (PCa), we characterized the somatic landscape of aggressive tumors via deep, whole-genome sequencing. In our discovery set of ten tumor/normal subject pairs with Gleason scores of 8-10 at diagnosis, coordinated analysis of germline and somatic variants, including single-nucleotide variants, indels, and structural variants, revealed biallelic BRCA2 disruptions in a subset of samples. Compared to the other samples, the PCa BRCA2-deficient tumors exhibited a complex and highly specific mutation signature, featuring a 2.88-fold increased somatic mutation rate, depletion of context-specific C>T substitutions, and an enrichment for deletions, especially those longer than 10 bp. We next performed a BRCA2 deficiency-targeted reanalysis of 150 metastatic PCa tumors, and each of the 18 BRCA2-mutated samples recapitulated the BRCA2 deficiency-associated mutation signature, underscoring the potent influence of these lesions on somatic mutagenesis and tumor evolution. Among all 21 individuals with BRCA2-deficient tumors, only about half carried deleterious germline alleles. Importantly, the somatic mutation signature in tumors with one germline and one somatic risk allele was indistinguishable from those with purely somatic mutations. Our observations clearly demonstrate that BRCA2-disrupted tumors represent a unique and clinically relevant molecular subtype of aggressive PCa, highlighting both the promise and utility of this mutation signature as a prognostic and treatment-selection biomarker. Further, any test designed to leverage BRCA2 status as a biomarker for PCa must consider both germline and somatic mutations and all types of deleterious mutations. Copyright © 2016 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  8. Adaptive synonymous mutations in an experimentally evolved Pseudomonas fluorescens population

    DEFF Research Database (Denmark)

    Bailey, Susan; Hinz, Aaron; Kassen, Rees


    Conventional wisdom holds that synonymous mutations, nucleotide changes that do not alter the encoded amino acid, have no detectable effect on phenotype or fitness. However, a growing body of evidence from both comparative and experimental studies suggests otherwise. Synonymous mutations have been...... in an experimentally evolved population of Pseudomonas fluorescens. We show experimentally that these mutations increase fitness by an amount comparable to non-synonymous mutations and that the fitness increases stem from increased gene expression. These results provide unequivocal evidence that synonymous mutations...... can drive adaptive evolution and suggest that this class of mutation may be underappreciated as a cause of adaptation and evolutionary dynamics....

  9. Recurrent APC gene mutations in Polish FAP families

    Directory of Open Access Journals (Sweden)

    Pławski Andrzej


    Full Text Available Abstract The molecular diagnostics of genetically conditioned disorders is based on the identification of the mutations in the predisposing genes. Hereditary cancer disorders of the gastrointestinal tracts are caused by mutations of the tumour suppressor genes or the DNA repair genes. Occurrence of recurrent mutation allows improvement of molecular diagnostics. The mutation spectrum in the genes causing hereditary forms of colorectal cancers in the Polish population was previously described. In the present work an estimation of the frequency of the recurrent mutations of the APC gene was performed. Eight types of mutations occurred in 19.4% of our FAP families and these constitute 43% of all Polish diagnosed families.

  10. Deep Mutational Scanning: A Highly Parallel Method to Measure the Effects of Mutation on Protein Function. (United States)

    Starita, Lea M; Fields, Stanley


    Deep mutational scanning is a method that makes use of next-generation sequencing technology to measure in a single experiment the activity of 10(5) or more unique variants of a protein. Because of this depth of mutational coverage, this strategy provides data that can be analyzed to reveal many protein properties. Deep mutational scanning approaches are particularly amenable to being performed in Saccharomyces cerevisiae, given the extensive toolkit of reagents and technologies available for this organism. © 2015 Cold Spring Harbor Laboratory Press.

  11. Asymptotics of steady states of a selection–mutation equation for small mutation rate

    KAUST Repository

    Calsina, Àngel


    We consider a selection-mutation equation for the density of individuals with respect to a continuous phenotypic evolutionary trait. We assume that the competition term for an individual with a given trait depends on the traits of all the other individuals, therefore giving an infinite-dimensional nonlinearity. Mutations are modelled by means of an integral operator. We prove existence of steady states and show that, when the mutation rate goes to zero, the asymptotic profile of the population is a Cauchy distribution. © Royal Society of Edinburgh 2013.

  12. 'A' by Aspergillus terreus through mutation

    African Journals Online (AJOL)



    Jan 24, 2012 ... been recommended as a mutagen of first choice. The ratio of mutation to lethality is usually high and is a relatively safe mutagen. The intrastrand cyclobutan pyri- midine dimer is the predominant DNA lesion reported to be produced by UV radiation. EMS is an alkylating agent and is known to produce ...

  13. Antifolate drug resistance: Novel mutations and haplotype ...

    Indian Academy of Sciences (India)

    N P Sarmah


    Sep 27, 2017 ... Malaria is a major public health concern in Northeast India with a preponderance of drug-resistant strains. Until recently ... India, were screened for malaria, and of these, 75 were found to be positive for Plasmodium falciparum. Samples ... Double mutation in dhfr gene causes intermediate resistance, while.

  14. Induced mutation to monocotyledony in periwinkle, Catharanthus ...

    Indian Academy of Sciences (India)


    A recessive EMS-induced mutation inherited in Mendelian fashion caused monocotyledonous embryo formation and seed germination on high salt medium in Catharanthus roseus. Availability during embryo development of exoge- nously supplied cytokinin kinetin suppressed the mutant phenotype. These observations ...

  15. Analysis of mutations causing familial hypercholesterolaemia in ...

    African Journals Online (AJOL)

    the LDLR (coding region, promoter and intron/exon boundaries), APOB (part of exon 26) and PCSK9 genes (exon 7), using high-resolution melting. Results. Eight LDLR mutations were identified, ... screened by four overlapping PCR fragments and exon 10 (228 bp) by two overlapping fragments. Amplification of most of the ...

  16. Mutation rate at swine microsatellite loci. (United States)

    Yue, Gen Hua; Beeckmann, Petra; Geldermann, Hermann


    During genotyping of 38 microsatellites for QTL (quantitative trait loci) mapping in three F2 swine populations, five mutant alleles were detected in a total of 66,436 parent-offspring transfers of microsatellite alleles, which gives an overall mutation rate of 7.52 x 10(-5) per locus per generation. No significant (P > 0.05) association between mutation rates and other factors (i.e., GC contents in the flanking regions, heterozygosity, and repeat number) was revealed. Detailed sequencing showed that four out of five mutant alleles were caused by insertions of one to five repeats, respectively. The other mutant allele was produced by either an insertion of three repeats or a change of 30 base pairs (a deletion of 16 CT repeats and an insertion of one CA repeat). An insertion of one base pair in the flanking region of a microsatellite was also detected. Together, these data indicate that expansions are more common than contractions among microsatellites and that the mutation processes are very complicated, do not fit with the strict stepwise mutation model and may vary from locus to locus.

  17. [Mutation voice disorders conditioned by psychic factors]. (United States)

    Wojciechowska, Anna; Obrebowski, Andrzej; Studzińska, Katarzyna; Swidziński, Piotr


    The case of 17 year old boy with mutational falsetto conditioned by a complex of psychic factors particulary with personality disorders and strong emotional bond with his mother was described. Phonation exercises lowered the average voice pitch. The stable results of phoniatric rehabilitation is dependent on effectiveness of psychological therapy of the whole family. Acoustic voice analysis demonstrates objectively the results of rehabilitation.

  18. The spontaneous chlorophyll mutation frequency in barley

    DEFF Research Database (Denmark)

    Jørgensen, Jørgen Helms; Jensen, Hans Peter


    materials and the resulting estimate of the chlorophyll mutant frequency is 1.6 .times. 10-4 in about 1.43 million seedlings. The estimate of the chlorophyll mutation rate per generation is close to 67.3 .times. 10-4 per diploid genome or in the order of 6 .times. 10-7 per locus and haploid genome....

  19. Mutation update for the PORCN gene

    DEFF Research Database (Denmark)

    Lombardi, Maria Paola; Bulk, Saskia; Celli, Jacopo


    variants and allows the inclusion of future reports. The database is based on the Leiden Open (source) Variation Database (LOVD) software, and is accessible online at At present, the database contains 106 variants, representing 68 different mutations, scattered along the whole...

  20. Mitochondrial mutations and polymorphisms in psychiatric disorders

    NARCIS (Netherlands)

    V. Sequeira (Vasco); M.V. Martin (Maureen); S.M. Rollins; E.A. Moon (Emily); W.E. Bunney (William E); F. MacCiardi (Fabio); S. Lupoli (Sara); G.D. Smith; J. Kelsoe (John); C.N. Magnan (Christophe); M. van Oven (Mannis); P. Baldi (Pierre); D.C. Wallace; M.P. Vawter (Marquis)


    textabstractMitochondrial deficiencies with unknown causes have been observed in schizophrenia (SZ) and bipolar disorder (BD) in imaging and postmortem studies. Polymorphisms and somatic mutations in mitochondrial DNA (mtDNA) were investigated as potential causes with next generation sequencing of

  1. Chromosomal localization of autosomal mutations in Drosophila ...

    Indian Academy of Sciences (India)


    We studied two eye colour and two wing mutants (sepia, brown, crossveinless and Curly) in Drosophila nasuta nasuta and four eye colour mutants (brown, carmine, pur- ple and bright eyes) in Drosophila nasuta albomicans. Most mutations were isolated from natural populations whereas two (crossveinless and Curly in D.

  2. Screening of three Mediterranean phenylketonuria mutations in ...

    Indian Academy of Sciences (India)

    Kaabachi N. 2012 Screening of three Mediterranean phenylketonuria mutations in Tunisian families. J. Genet. 91, 91–94]. Introduction. Phenylketonuria (PKU; OMIM 261600) is an autoso- mal recessive disease caused by the liver phenylalanine hydroxylase (PAH) enzyme (EC1.14.16.1) deficiency. If untreated, causes ...

  3. Intersex (ix) mutations of Drosophila melanogaster cause ...

    Indian Academy of Sciences (India)

    This study on the effect of different intersex mutations on genital disc development provides the following major results: (i) similar range of a characteristic array of morphological structures (from almost double sex terminalia to extreme reduction of terminal appendages) was displayed by the terminalia of XX ix1/ix1, XX ...

  4. Rhodopsin mutations are scarcely implicated in autosomal ...

    African Journals Online (AJOL)

    Reem Mebed


    Apr 23, 2015 ... Rhodopsin mutations are scarcely implicated in autosomal recessive retinitis pigmentosa: A preliminary study of Egyptian retinitis pigmentosa patients. Reem Mebed a,. *, Yasser B.M. Ali b. , Nahed Solouma c. , Amr Eldib d. ,. Mahmoud Amer e. , Ahmed Osman e,f a National Organization for Research and ...

  5. Mutational Analysis of Merkel Cell Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Erstad, Derek J. [Department of Surgery, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114 (United States); Cusack, James C. Jr., E-mail: [Division of Surgical Oncology, Harvard Medical School, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114 (United States)


    Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine malignancy that is associated with a poor prognosis. The pathogenesis of MCC is not well understood, and despite a recent plethora of mutational analyses, we have yet to find a set of signature mutations implicated in the majority of cases. Mutations, including TP53, Retinoblastoma and PIK3CA, have been documented in subsets of patients. Other mechanisms are also likely at play, including infection with the Merkel cell polyomavirus in a subset of patients, dysregulated immune surveillance, epigenetic alterations, aberrant protein expression, posttranslational modifications and microRNAs. In this review, we summarize what is known about MCC genetic mutations and chromosomal abnormalities, and their clinical significance. We also examine aberrant protein function and microRNA expression, and discuss the therapeutic and prognostic implications of these findings. Multiple clinical trials designed to selectively target overexpressed oncogenes in MCC are currently underway, though most are still in early phases. As we accumulate more molecular data on MCC, we will be better able to understand its pathogenic mechanisms, develop libraries of targeted therapies, and define molecular prognostic signatures to enhance our clinicopathologic knowledge.

  6. Antifolate drug resistance: Novel mutations and haplotype ...

    Indian Academy of Sciences (India)

    Malaria is a major public health concern in Northeast India with a preponderance of drug-resistant strains. Until recently thepartner drug for artemisinin combination therapy (ACT) was sulphadoxine pyrimethamine (SP). Antifolate drug resistancehas been associated with the mutations at dihydropteroate synthase (dhps) and ...

  7. Upper Bounds for Mutations of Potentials

    Directory of Open Access Journals (Sweden)

    John Alexander Cruz Morales


    Full Text Available In this note we provide a new, algebraic proof of the excessive Laurent phenomenon for mutations of potentials (in the sense of [Galkin S., Usnich A., Preprint IPMU 10-0100, 2010] by introducing to this theory the analogue of the upper bounds from [Berenstein A., Fomin S., Zelevinsky A., Duke Math. J. 126 (2005, 1-52].

  8. From Gene Mutation to Protein Characterization (United States)

    Moffet, David A.


    A seven-week "gene to protein" laboratory sequence is described for an undergraduate biochemistry laboratory course. Student pairs were given the task of introducing a point mutation of their choosing into the well studied protein, enhanced green fluorescent protein (EGFP). After conducting literature searches, each student group chose the…

  9. The inheritance of pathogenic mitochondrial DNA mutations. (United States)

    Cree, L M; Samuels, D C; Chinnery, P F


    Mitochondrial DNA mutations cause disease in >1 in 5000 of the population, and approximately 1 in 200 of the population are asymptomatic carriers of a pathogenic mtDNA mutation. Many patients with these pathogenic mtDNA mutations present with a progressive, disabling neurological syndrome that leads to major disability and premature death. There is currently no effective treatment for mitochondrial disorders, placing great emphasis on preventing the transmission of these diseases. An empiric approach can be used to guide genetic counseling for common mtDNA mutations, but many families transmit rare or unique molecular defects. There is therefore a pressing need to develop techniques to prevent transmission based on a solid understanding of the biological mechanisms. Several recent studies have cast new light on the genetics and cell biology of mtDNA inheritance, but these studies have also raised new controversies. Here we compare and contrast these findings and discuss their relevance for the transmission of human mtDNA diseases.

  10. The mutation spectrum in RECQL4 diseases

    NARCIS (Netherlands)

    Siitonen, H. Annika; Sotkasiira, Jenni; Biervliet, Martine; Benmansour, Abdelmadjid; Capri, Yline; Cormier-Daire, Valerie; Crandall, Barbara; Hannula-Jouppi, Katariina; Hennekam, Raoul; Herzog, Denise; Keymolen, Kathelijn; Lipsanen-Nyman, Marita; Miny, Peter; Plon, Sharon E.; Riedl, Stefan; Sarkar, Ajoy; Vargas, Fernando R.; Verloes, Alain; Wang, Lisa L.; Kääriäinen, Helena; Kestilä, Marjo


    Mutations in the RECQL4 gene can lead to three clinical phenotypes with overlapping features. All these syndromes, Rothmund-Thomson (RTS), RAPADILINO and Baller-Gerold (BGS), are characterized by growth retardation and radial defects, but RAPADILINO syndrome lacks the main dermal manifestation,

  11. Mitochondrial mutations in subjects with psychiatric disorders.

    Directory of Open Access Journals (Sweden)

    Adolfo Sequeira

    Full Text Available A considerable body of evidence supports the role of mitochondrial dysfunction in psychiatric disorders and mitochondrial DNA (mtDNA mutations are known to alter brain energy metabolism, neurotransmission, and cause neurodegenerative disorders. Genetic studies focusing on common nuclear genome variants associated with these disorders have produced genome wide significant results but those studies have not directly studied mtDNA variants. The purpose of this study is to investigate, using next generation sequencing, the involvement of mtDNA variation in bipolar disorder, schizophrenia, major depressive disorder, and methamphetamine use. MtDNA extracted from multiple brain regions and blood were sequenced (121 mtDNA samples with an average of 8,800x coverage and compared to an electronic database containing 26,850 mtDNA genomes. We confirmed novel and rare variants, and confirmed next generation sequencing error hotspots by traditional sequencing and genotyping methods. We observed a significant increase of non-synonymous mutations found in individuals with schizophrenia. Novel and rare non-synonymous mutations were found in psychiatric cases in mtDNA genes: ND6, ATP6, CYTB, and ND2. We also observed mtDNA heteroplasmy in brain at a locus previously associated with schizophrenia (T16519C. Large differences in heteroplasmy levels across brain regions within subjects suggest that somatic mutations accumulate differentially in brain regions. Finally, multiplasmy, a heteroplasmic measure of repeat length, was observed in brain from selective cases at a higher frequency than controls. These results offer support for increased rates of mtDNA substitutions in schizophrenia shown in our prior results. The variable levels of heteroplasmic/multiplasmic somatic mutations that occur in brain may be indicators of genetic instability in mtDNA.

  12. Clinical mutation assay of tumors: new developments. (United States)

    Starostik, Petr


    Mutation detection in tumors started with classical cytogenetics as the method of choice more than 50 years ago. Karyotyping proved to be sensitive enough to detect deletions or duplications of large chromosome segments, and translocations. Over time, new techniques were developed to detect mutations that are much smaller in scope. The availability of Sanger sequencing and the invention of the PCR improved the discriminatory power of mutation detection to just one base change in the genomic DNA sequence. Techniques derived from PCR (allele-specific PCR, qPCR) and improved or modified sequencing methods (capillary electrophoresis, pyrosequencing) considerably increased the efficiency and sample throughput of mutation detection assays. With the advent of massive parallel sequencing [also called next-generation sequencing (NGS)] in the past decade, a major shift to even higher sample throughput and a significant decrease in cost per sequenced base occurred. The application of the new technology provided a whole slew of novel biomarkers and potential therapy targets to improve diagnosis and treatment. It even led to changes in cancer classification as new information on the mutation profile of tumors became available that characterizes some disease entities better than morphology. NGS, which usually interrogates multiple genes at once and is a prime example of a multianalyte assay, started to replace older single analyte assays focused on analysis of one target, one gene. However, the transition to these extremely complex NGS-based assays is associated with multiple challenges. There are issues with adequate tissue source of nucleic acids, sequencing library preparation, bioinformatics, government regulations and oversight, reimbursement, and electronic medical records that need to be resolved to successfully implement the new technology in a clinical laboratory.

  13. Wolfram Syndrome: New Mutations, Different Phenotype (United States)

    Pasquali, Lorenzo; Lugani, Francesca; Perri, Katia; Russo, Chiara; Tallone, Ramona; Ghiggeri, Gian Marco; Lorini, Renata; d'Annunzio, Giuseppe


    Background Wolfram Syndrome (WS) is an autosomal recessive neurodegenerative disorder characterized by Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy, and Deafness identified by the acronym “DIDMOAD”. The WS gene, WFS1, encodes a transmembrane protein called Wolframin, which recent evidence suggests may serve as a novel endoplasmic reticulum calcium channel in pancreatic β-cells and neurons. WS is a rare disease, with an estimated prevalence of 1/550.000 children, with a carrier frequency of 1/354. The aim of our study was to determine the genotype of WS patients in order to establish a genotype/phenotype correlation. Methodology/Principal Findings We clinically evaluated 9 young patients from 9 unrelated families (6 males, 3 females). Basic criteria for WS clinical diagnosis were coexistence of insulin-treated diabetes mellitus and optic atrophy occurring before 15 years of age. Genetic analysis for WFS1 was performed by direct sequencing. Molecular sequencing revealed 5 heterozygous compound and 3 homozygous mutations. All of them were located in exon 8, except one in exon 4. In one proband only an heterozygous mutation (A684V) was found. Two new variants c.2663 C>A and c.1381 A>C were detected. Conclusions/Significance Our study increases the spectrum of WFS1 mutations with two novel variants. The male patient carrying the compound mutation [c.1060_1062delTTC]+[c.2663 C>A] showed the most severe phenotype: diabetes mellitus, optic atrophy (visual acuity 5/10), deafness with deep auditory bilaterally 8000 Hz, diabetes insipidus associated to reduced volume of posterior pituitary and pons. He died in bed at the age of 13 years. The other patient carrying the compound mutation [c.409_424dup16]+[c.1381 A>C] showed a less severe phenotype (DM, OA). PMID:22238590

  14. Coherent Somatic Mutation in Autoimmune Disease (United States)

    Ross, Kenneth Andrew


    Background Many aspects of autoimmune disease are not well understood, including the specificities of autoimmune targets, and patterns of co-morbidity and cross-heritability across diseases. Prior work has provided evidence that somatic mutation caused by gene conversion and deletion at segmentally duplicated loci is relevant to several diseases. Simple tandem repeat (STR) sequence is highly mutable, both somatically and in the germ-line, and somatic STR mutations are observed under inflammation. Results Protein-coding genes spanning STRs having markers of mutability, including germ-line variability, high total length, repeat count and/or repeat similarity, are evaluated in the context of autoimmunity. For the initiation of autoimmune disease, antigens whose autoantibodies are the first observed in a disease, termed primary autoantigens, are informative. Three primary autoantigens, thyroid peroxidase (TPO), phogrin (PTPRN2) and filaggrin (FLG), include STRs that are among the eleven longest STRs spanned by protein-coding genes. This association of primary autoantigens with long STR sequence is highly significant (). Long STRs occur within twenty genes that are associated with sixteen common autoimmune diseases and atherosclerosis. The repeat within the TTC34 gene is an outlier in terms of length and a link with systemic lupus erythematosus is proposed. Conclusions The results support the hypothesis that many autoimmune diseases are triggered by immune responses to proteins whose DNA sequence mutates somatically in a coherent, consistent fashion. Other autoimmune diseases may be caused by coherent somatic mutations in immune cells. The coherent somatic mutation hypothesis has the potential to be a comprehensive explanation for the initiation of many autoimmune diseases. PMID:24988487

  15. Hereditary non-polyposis colorectal cancer : Identification of mutation carriers and assessing pathogenicity of mutations

    NARCIS (Netherlands)

    Niessen, RC; Sijmons, RH; Berends, MJW; Ou, J; Hofstra, RNW; Kleibeuker, JH


    Hereditary non-polyposis colorectal cancer (HNPCC), also referred to as Lynch syndrome, is an autosomal dominantly inherited disorder that is characterized by susceptibility to colorectal cancer and extracolonic malignancies, in particular endometrial cancer. HNPCC is caused by pathogenic mutations

  16. AChR deficiency due to ε-subunit mutations: Two common mutations in the Netherlands

    NARCIS (Netherlands)

    C.G. Faber (Carin); P.C. Molenaar (Peter); J.S.H. Vles (Johannes); D.M. Bonifati (Domenic); J.J. Verschuuren (Jan); P.A. van Doorn (Pieter); J.B.M. Kuks (Jan); J.H.J. Wokke (John); D. Beeson (David); M.H. de Baets (Marc)


    textabstractCongenital myasthenic syndromes are a clinically and genetically heterogeneous group of hereditary disorders affecting neuromuscular transmission. We have identified mutations within the acetylcholine receptor (AChR) ε-subunit gene underlying congenital myasthenic syndromes in nine

  17. AChR deficiency due to epsilon-subunit mutations : two common mutations in the Netherlands

    NARCIS (Netherlands)

    Faber, Catharina G.; Molenaar, Peter C.; Vles, Johannes S. H.; Bonifati, Domenic M.; Verschuuren, Jan J. G. M.; van Doorn, Pieter A.; Kuks, Jan B. M.; Wokke, John H. J.; Beeson, David; De Baets, Marc


    Congenital myasthenic syndromes are a clinically and genetically heterogeneous group of hereditary disorders affecting neuromuscular transmission. We have identified mutations within the acetylcholine receptor (AChR) epsilon-subunit gene underlying congenital myasthenic syndromes in nine patients

  18. Preaxial polydactyly associated with a MSX1 mutation and report of two novel mutations. (United States)

    Wattanarat, Onnida; Kantaputra, Piranit Nik


    We report two novel heterozygous missense MSX1 mutations in two Thai families (c.739C>T; p.Pro247Ser and c.607G>A; p.Ala203Thr). The p.Ala203Thr mutation was found in a female patient, her sister, and their father and is associated with unilateral cleft lip and palate, hypodontia, and microdontia. The p.Pro247Ser mutation was found in a three-generation Thai family and was associated with bilateral cleft lip and palate, hypodontia, microdontia, and dens invaginatus. The proband also had preaxial polydactyly of the left hand. The role of Msx1 in limb development in mice is discussed. Intrafamilial variability of the phenotypes is clearly evident. This is the first time that a limb anomaly has been reported to be associated with a mutation in MSX1. © 2015 Wiley Periodicals, Inc.

  19. A Naturally Occurring hPMS2 Mutation Can Confer a Dominant Negative Mutator Phenotype (United States)

    Nicolaides, Nicholas C.; Littman, Susan J.; Modrich, Paul; Kinzler, Kenneth W.; Vogelstein, Bert


    Defects in mismatch repair (MMR) genes result in a mutator phenotype by inducing microsatellite instability (MI), a characteristic of hereditary nonpolyposis colorectal cancers (HNPCC) and a subset of sporadic colon tumors. Present models describing the mechanism by which germ line mutations in MMR genes predispose kindreds to HNPCC suggest a “two-hit” inactivation of both alleles of a particular MMR gene. Here we present experimental evidence that a nonsense mutation at codon 134 of the hPMS2 gene is sufficient to reduce MMR and induce MI in cells containing a wild-type hPMS2 allele. These results have significant implications for understanding the relationship between mutagenesis and carcinogenesis and the ability to generate mammalian cells with mutator phenotypes. PMID:9488480

  20. Gene Mutation in Neonatal Jaundice - Mutations in UGT1A1 and OATP2 Genes. (United States)

    Min, Jiang; Jie, Luo; Caiyun, Yang; Ying, Lin; Xuefang, Yang


    This study evaluated the correlation of UGT1A1, OATP2 gene mutations and hyperbilirubinemia in newborns in Northern China. Gene mutations were analyzed at the 211 locus of UGT1A1 (Gly71Arg) and 388 locus of OATP2 (Asn130Asp). The 226 enrolled infants were divided into high, moderate, and low risk subgroups according to American Academy of Pediatrics guideline. Blood samples of the enrolled infants were collected for the analysis of the PCR-restriction fragment length polymorphism. The genotypes and allele frequencies of the polymorphisms were compared in each group. Both UGT1A1 and OATP2 gene mutations occur more often in high risk group and moderate risk group than in low risk group. The results suggested that Gly71Arg and Asn130Asp mutations in UGT1A1 and OATP2 genes might be involved in the development of hyperbilirubinemia in neonates.

  1. Simulation Study for Transfer of Antibiotic Resistance via Mutator Subpopulation

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Aarestrup, Frank Møller

    Evolution of antibiotic resistance in bacterial populations is an increasing problem having fatal consequences for treatment of diseases. Therefore it is very important to understand this evolution. Traditionally evolution is considered to happen by single point mutations, where each mutant must...... have a growth advantage over the parent strain and grow to a sufficient number before a second mutation can occur. However, when multiple mutations are necessary for development of resistance, single mutations occurring with a normal mutation rate can not always explain the observed resistance. We...... introduce an alternative hypothesis by which a subpopulation of mutators drives the evolution process. Resistance is acquired by a subpoplution of mutators, for which the mutation rate is much higher than the wild-type. If the resistance is located on a transferable plasmid it can subsequently...

  2. Fundus albipunctatus associated with compound heterozygous mutations in RPE65

    DEFF Research Database (Denmark)

    Schatz, Patrik; Preising, Markus; Lorenz, Birgit


    To describe a family with an 18-year-old woman with fundus albipunctatus and compound heterozygous mutations in RPE65 whose unaffected parents and 1 female sibling harbored single heterozygous RPE65 mutations....

  3. Illness perceptions, risk perception and worry in SDH mutation carriers

    NARCIS (Netherlands)

    Hulsteijn, L.T. van; Kaptein, A.A.; Louisse, A.; Biermasz, N.R.; Smit, J.W.; Corssmit, E.P.


    Succinate dehydrogenase (SDH) mutation carriers are predisposed for developing paragangliomas. This study aimed to explore illness perceptions, risk perception and disease-related worry in these individuals. All consecutive SDHB and SDHD mutation carriers followed at the Department of Endocrinology

  4. Childhood Cancer Radiation May Cause Unwanted Gene Mutation in Some (United States)

    ... 167614.html Childhood Cancer Radiation May Cause Unwanted Gene Mutation in Some That flaw seems to increase risk ... and now researchers say they've found a gene mutation that seems to increase that risk. The researchers ...

  5. Toward a Unique Definition of the Mutation Rate. (United States)

    Zheng, Qi


    In around 1943, while writing a classic paper with Luria, Delbrück envisioned two kinds of mutation rates: One was expressed as mutations per bacterium per unit time, the other as mutations per bacterium per division cycle. Due to minor mathematical errors, the precise connection between the two concepts remained elusive for Delbrück. As a result, researchers and educators alike are still grappling with the definition of the mutation rate. Within the context of microbial mutation, the current author proposes an idealized model to bring new clarity to the distinction between the two forms of the mutation rate that Delbrück once attempted to define and characterize. The paper also critiques two incorrect estimators of mutation rates and brings to light two important yet unexplored "invariance" hypotheses about mutation rates.

  6. An MRPS12 mutation modifies aminoglycoside sensitivity caused by 12S rRNA mutations

    Directory of Open Access Journals (Sweden)

    Sonia eEmperador


    Full Text Available Several homoplasmic pathologic mutations in mitochondrial DNA, such as those causing Leber hereditary optic neuropathy or non-syndromic hearing loss, show incomplete penetrance. Therefore, other elements must modify their pathogenicity. Discovery of these modifying factors is not an easy task because in multifactorial diseases conventional genetic approaches may not always be informative.Here, we have taken an evolutionary approach to unmask putative modifying factors for a particular homoplasmic pathologic mutation causing aminoglycoside-induced and non-syndromic hearing loss, the m.1494C>T transition in the mitochondrial DNA. The mutation is located in the decoding site of the mitochondrial ribosomal RNA. We first looked at mammalian species that had fixed the human pathologic mutation. These mutations are called compensated pathogenic deviations because an organism carrying one must also have another that suppresses the deleterious effect of the first. We found that species from the primate family Cercopithecidae (old world monkeys harbor the m.1494T allele even if their auditory function is normal.In humans the m.1494T allele increases the susceptibility to aminoglycosides. However, in primary fibroblasts from a Cercopithecidae species, aminoglycosides do not impair cell growth, respiratory complex IV activity and quantity or the mitochondrial protein synthesis. Interestingly, these species also carry a fixed mutation in the mitochondrial ribosomal protein S12. We show that the expression of this variant in a human m.1494T cell line reduces its susceptibility to aminoglycosides. Because several mutations in this human protein have been described, they may possibly explain the absence of pathologic phenotype in some pedigree members with the most frequent pathologic mutations in mitochondrial ribosomal RNA.

  7. A systematic study of gene mutations in urothelial carcinoma; inactivating mutations in TSC2 and PIK3R1.

    Directory of Open Access Journals (Sweden)

    Gottfrid Sjödahl

    Full Text Available BACKGROUND: Urothelial carcinoma (UC is characterized by frequent gene mutations of which activating mutations in FGFR3 are the most frequent. Several downstream targets of FGFR3 are also mutated in UC, e.g., PIK3CA, AKT1, and RAS. Most mutation studies of UCs have been focused on single or a few genes at the time or been performed on small sample series. This has limited the possibility to investigate co-occurrence of mutations. METHODOLOGY/PRINCIPAL FINDINGS: We performed mutation analyses of 16 genes, FGFR3, PIK3CA, PIK3R1 PTEN, AKT1, KRAS, HRAS, NRAS, BRAF, ARAF, RAF1, TSC1, TSC2, APC, CTNNB1, and TP53, in 145 cases of UC. We show that FGFR3 and PIK3CA mutations are positively associated. In addition, we identified PIK3R1 as a target for mutations. We demonstrate a negative association at borderline significance between FGFR3 and RAS mutations, and show that these mutations are not strictly mutually exclusive. We show that mutations in BRAF, ARAF, RAF1 rarely occurs in UC. Our data emphasize the possible importance of APC signaling as 6% of the investigated tumors either showed inactivating APC or activating CTNNB1 mutations. TSC1, as well as TSC2, that constitute the mTOR regulatory tuberous sclerosis complex were found to be mutated at a combined frequency of 15%. CONCLUSIONS/SIGNIFICANCE: Our data demonstrate a significant association between FGFR3 and PIK3CA mutations in UC. Moreover, the identification of mutations in PIK3R1 further emphasizes the importance of the PI3-kinase pathway in UC. The presence of TSC2 mutations, in addition to TSC1 mutations, underlines the involvement of mTOR signaling in UC.

  8. Contributions of intrinsic mutation rate and selfish selection to levels of de novo HRAS mutations in the paternal germline. (United States)

    Giannoulatou, Eleni; McVean, Gilean; Taylor, Indira B; McGowan, Simon J; Maher, Geoffrey J; Iqbal, Zamin; Pfeifer, Susanne P; Turner, Isaac; Burkitt Wright, Emma M M; Shorto, Jennifer; Itani, Aysha; Turner, Karen; Gregory, Lorna; Buck, David; Rajpert-De Meyts, Ewa; Looijenga, Leendert H J; Kerr, Bronwyn; Wilkie, Andrew O M; Goriely, Anne


    The RAS proto-oncogene Harvey rat sarcoma viral oncogene homolog (HRAS) encodes a small GTPase that transduces signals from cell surface receptors to intracellular effectors to control cellular behavior. Although somatic HRAS mutations have been described in many cancers, germline mutations cause Costello syndrome (CS), a congenital disorder associated with predisposition to malignancy. Based on the epidemiology of CS and the occurrence of HRAS mutations in spermatocytic seminoma, we proposed that activating HRAS mutations become enriched in sperm through a process akin to tumorigenesis, termed selfish spermatogonial selection. To test this hypothesis, we quantified the levels, in blood and sperm samples, of HRAS mutations at the p.G12 codon and compared the results to changes at the p.A11 codon, at which activating mutations do not occur. The data strongly support the role of selection in determining HRAS mutation levels in sperm, and hence the occurrence of CS, but we also found differences from the mutation pattern in tumorigenesis. First, the relative prevalence of mutations in sperm correlates weakly with their in vitro activating properties and occurrence in cancers. Second, specific tandem base substitutions (predominantly GC>TT/AA) occur in sperm but not in cancers; genomewide analysis showed that this same mutation is also overrepresented in constitutional pathogenic and polymorphic variants, suggesting a heightened vulnerability to these mutations in the germline. We developed a statistical model to show how both intrinsic mutation rate and selfish selection contribute to the mutational burden borne by the paternal germline.

  9. Yeast Interacting Proteins Database: YJR091C, YDR389W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available to the actin cytoskeleton, null mutations suppress tor2 mutations and temperature sensitive mutations in act...ion GTPase activating protein (GAP) for Rho1p, involved in signaling to the actin cytoskeleton, null mutations suppress tor2 mutation...s and temperature sensitive mutations in actin; potential Cdc28p substrate Rows wit

  10. Frameshift mutations in dentin phosphoprotein and dependence of dentin disease phenotype on mutation location. (United States)

    Nieminen, Pekka; Papagiannoulis-Lascarides, Lisa; Waltimo-Siren, Janna; Ollila, Päivi; Karjalainen, Sara; Arte, Sirpa; Veerkamp, Jaap; Tallon Walton, Victoria; Chimenos Küstner, Eduard; Siltanen, Tarja; Holappa, Heidi; Lukinmaa, Pirjo-Liisa; Alaluusua, Satu


    We describe results from a mutational analysis of the region of the dentin sialophosphoprotein (DSPP) gene encoding dentin phosphoprotein (DPP) in 12 families with dominantly inherited dentin diseases. In eight families (five mutations in the N-terminal third of DPP), the clinical and radiologic features were uniform and compatible with dentin dysplasia type II (DD-II) with major clinical signs in the deciduous dentition. In the other families (four mutations in the more C-terminal part), the permanent teeth also were affected, and the diseases could be classified as variants of dentinogenesis imperfecta. Attrition was not prominent, but periapical infections were common. Discoloring with varying intensity was evident, and pulps and root canals were obliterated in the permanent dentition. All mutations caused a frameshift that replaced the Ser-Ser-Asx repeat by a code for a hydrophobic downstream sequence of approximately original length. We conclude that frameshift mutations in DSPP explain a significant part of dentin diseases. Furthermore, we propose that the location of the mutation is reflected in the phenotypic features as a gradient from DD-II to more severe disease that does not conform to the classic definitions of DI-II. Copyright © 2011 American Society for Bone and Mineral Research.

  11. RAS mutations and oncogenesis: not all RAS mutations are created equally

    Directory of Open Access Journals (Sweden)

    Mark Steven Miller


    Full Text Available Mutation in RAS proteins is one of the most common genetic alterations observed in human and experimentally induced rodent cancers. In vivo, oncogenic mutations have been shown to occur at exons 12, 13, and 61, resulting in any one of 19 possible point mutations in a given tumor for a specific RAS isoform. While some studies have suggested a possible role of allele-specific mutation in determining tumor severity and phenotype, no general consensus has emerged on the oncogenicity of different mutant alleles in tumor formation and progression. Part of this may be due to a lack of a single, signature pathway that shows significant alterations between different mutations. Rather, it is likely that subtle differences in the activation, or lack thereof, of downstream effectors by different RAS mutant alleles may determine the eventual outcome in terms of tumor phenotype. This paper reviews our current understanding of the potential role of different RAS mutations on tumorigenesis, highlights studies in model cell culture and in vivo systems, and discusses the potential of expression array and computational network modeling to dissect out differences in activated RAS genes in conferring a transforming phenotype.

  12. SERPINA1 Full-Gene Sequencing Identifies Rare Mutations Not Detected in Targeted Mutation Analysis. (United States)

    Graham, Rondell P; Dina, Michelle A; Howe, Sarah C; Butz, Malinda L; Willkomm, Kurt S; Murray, David L; Snyder, Melissa R; Rumilla, Kandelaria M; Halling, Kevin C; Highsmith, W Edward


    Genetic α-1 antitrypsin (AAT) deficiency is characterized by low serum AAT levels and the identification of causal mutations or an abnormal protein. It needs to be distinguished from deficiency because of nongenetic causes, and diagnostic delay may contribute to worse patient outcome. Current routine clinical testing assesses for only the most common mutations. We wanted to determine the proportion of unexplained cases of AAT deficiency that harbor causal mutations not identified through current standard allele-specific genotyping and isoelectric focusing (IEF). All prospective cases from December 1, 2013, to October 1, 2014, with a low serum AAT level not explained by allele-specific genotyping and IEF were assessed through full-gene sequencing with a direct sequencing method for pathogenic mutations. We reviewed the results using American Council of Medical Genetics criteria. Of 3523 cases, 42 (1.2%) met study inclusion criteria. Pathogenic or likely pathogenic mutations not identified through clinical testing were detected through full-gene sequencing in 16 (38%) of the 42 cases. Rare mutations not detected with current allele-specific testing and IEF underlie a substantial proportion of genetic AAT deficiency. Full-gene sequencing, therefore, has the ability to improve accuracy in the diagnosis of AAT deficiency. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  13. Mutation analysis in Norwegian families with hereditary hemorrhagic telangiectasia: founder mutations in ACVRL1. (United States)

    Heimdal, K; Dalhus, B; Rødningen, O K; Kroken, M; Eiklid, K; Dheyauldeen, S; Røysland, T; Andersen, R; Kulseth, M A


    Hereditary hemorrhagic telangiectasia (HHT, Osler-Weber-Rendu disease) is an autosomal dominant inherited disease defined by the presence of epistaxis and mucocutaneous telangiectasias and arteriovenous malformations (AVMs) in internal organs. In most families (~85%), HHT is caused by mutations in the ENG (HHT1) or the ACVRL1 (HHT2) genes. Here, we report the results of genetic testing of 113 Norwegian families with suspected or definite HHT. Variants in ENG and ACVRL1 were found in 105 families (42 ENG, 63 ACVRL1), including six novel variants of uncertain pathogenic significance. Mutation types were similar to previous reports with more missense variants in ACVRL1 and more nonsense, frameshift and splice-site mutations in ENG. Thirty-two variants were novel in this study. The preponderance of ACVRL1 mutations was due to founder mutations, specifically, c.830C>A (p.Thr277Lys), which was found in 24 families from the same geographical area of Norway. We discuss the importance of founder mutations and present a thorough evaluation of missense and splice-site variants. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. The molecular landscape of ASPM mutations in primary microcephaly. (United States)

    Nicholas, A K; Swanson, E A; Cox, J J; Karbani, G; Malik, S; Springell, K; Hampshire, D; Ahmed, M; Bond, J; Di Benedetto, D; Fichera, M; Romano, C; Dobyns, W B; Woods, C G


    Autosomal recessive primary microcephaly (MCPH) is a model disease to study human neurogenesis. In affected individuals the brain grows at a reduced rate during fetal life resulting in a small but structurally normal brain and mental retardation. The condition is genetically heterogeneous with mutations in ASPM being most commonly reported. We have examined this further by studying three cohorts of microcephalic children to extend both the phenotype and the mutation spectrum. Firstly, in 99 consecutively ascertained consanguineous families with a strict diagnosis of MCPH, 41 (41%) were homozygous at the MCPH5 locus and all but two families had mutations. Thus, 39% of consanguineous MCPH families had homozygous ASPM mutations. Secondly, in 27 non-consanguineous, predominantly Caucasian families with a strict diagnosis of MCPH, 11 (40%) had ASPM mutations. Thirdly, in 45 families with a less restricted phenotype including microcephaly and mental retardation, but regardless of other neurological features, only 3 (7%) had an ASPM mutation. This report contains 27 novel mutations and almost doubles the number of MCPH associated ASPM mutations known to 57. All but one of the mutations lead to the use of a premature termination codon, 23 were nonsense mutations, 28 deletions or insertions, 5 splicing, and 1 was a translocation. Seventeen of the 57 mutations were recurrent. There were no definitive missense mutations found nor was there any mutation/phenotype correlation. ASPM mutations were found in all ethnic groups studied. This study confirms that mutations in ASPM are the most common cause of MCPH, that ASPM mutations are restricted to individuals with an MCPH phenotype, and that ASPM testing in primary microcephaly is clinically useful.

  15. Epistatic Mutations And Unpredictable Phenotypes In Pseudomonas Aeruginosa

    DEFF Research Database (Denmark)

    Andresen, Eva Kammer; Abou Hachem, Maher; Jelsbak, Lars


    factors. The phenotypic changes arise from mutations in trans-regulatory elements but are nearly impossible to predict from sequence data alone. Often, the combinatorial effects of few mutations in global regulators give rise to unexpected phenotypes. To understand the epistatic effect and how unexpected...... phenotypes arise from seemingly unrelated mutations, we have studied two mutations in P. aeruginosa transcriptional regulators, sigma factor rpoD and algT....

  16. Fundus albipunctatus associated with compound heterozygous mutations in RPE65

    DEFF Research Database (Denmark)

    Schatz, Patrik; Preising, Markus; Lorenz, Birgit


    To describe a family with an 18-year-old woman with fundus albipunctatus and compound heterozygous mutations in RPE65 whose unaffected parents and 1 female sibling harbored single heterozygous RPE65 mutations.......To describe a family with an 18-year-old woman with fundus albipunctatus and compound heterozygous mutations in RPE65 whose unaffected parents and 1 female sibling harbored single heterozygous RPE65 mutations....

  17. Mutational processes molding the genomes of 21 breast cancers

    NARCIS (Netherlands)

    S. Nik-Zainal (Serena); L.B. Alexandrov (Ludmil); D.C. Wedge (David); P. van Loo (Peter); C. Greenman (Chris); J.W. Raine (John); D. Jones (David); J. Hinton (Jonathan); J. Marshall (John); L.A. Stebbings (Lucy); D. Menzies; S. Martin (Sandra); K. Leung (Kenric); L. Chen (Lina); C. Leroy (Catherine); M. Ramakrishna (Manasa); R. Rance (Richard); K.W. Lau (King Wai); L. Mudie (Laura); I. Varela (Ignacio); D.J. McBride (David); G.R. Bignell (Graham); S.L. Cooke (Susanna); A. Shlien (Adam); J. Gamble (John); I. Whitmore (Ian); M. Maddison (Mark); P.S. Tarpey (Patrick); H. Davies (Helen); E. Papaemmanuil (Elli); P.J. Stephens (Philip); S. McLaren (Stuart); A. Butler (Adam); J. Teague (Jon); G. Jönsson (Göran); J. Garber; R.A. Silver (Angus); P. Miron (Penelope); A. Fatima (Aquila); S. Boyault (Sandrine); A. Langerød (Anita); A. Tutt (Andrew); J.W.M. Martens (John); S.A.J.R. Aparicio (Samuel A. J.); Å. Borg (Åke); A.V. Salomon (Anne Vincent); G. Thomas (Gilles); A.-L. Borresen-Dale (Anne-Lise); A.L. Richardson (Andrea); M.S. Neuberger (Michael); P.A. Futreal (Andrew); P.J. Campbell (Peter); M.R. Stratton (Michael)


    textabstractAll cancers carry somatic mutations. The patterns of mutation in cancer genomes reflect the DNA damage and repair processes to which cancer cells and their precursors have been exposed. To explore these mechanisms further, we generated catalogs of somatic mutation from 21 breast cancers

  18. Higher prevalence of KRAS mutations in colorectal cancer in Saudi ...

    African Journals Online (AJOL)

    KRAS mutation is widely accepted as a key factor in colorectal tumorigenesis. Although KRAS mutation is widely studied in CRC limited data are available about mutation rates and spectrum in CRC from developing countries like Saudi Arabia where epidemiological features of the disease are different. We studied ...

  19. Generation of mutation hotspots in ageing bacterial colonies

    DEFF Research Database (Denmark)

    Sekowska, Agnieszka; Wendel, Sofie; Christian Fischer, Emil


    : most mutations were located in just a few hotspots in the genome, and over time, mutations increasingly were consistent with the involvement of 8-oxo-guanosine, formed exclusively on the transcribed strand. This work provides strong support for retromutagenesis as a general process creating adaptive...... mutations during ageing....

  20. Discordant diagnoses obtained by different approaches in antithrombin mutation analysis

    DEFF Research Database (Denmark)

    Feddersen, Søren; Nybo, Mads


    with a negative DHPLC mutation screening, discordant results were found in ten patients (62.5%) when using direct sequencing: Eight had the Basel mutation (c.218C>T), while two had the Cambridge II mutation (c.1246G>T). For seven of the ten patients this meant an altered clinical risk-assessment for future...

  1. Spectrum of small mutations in the dystrophin coding region. (United States)

    Prior, T W; Bartolo, C; Pearl, D K; Papp, A C; Snyder, P J; Sedra, M S; Burghes, A H; Mendell, J R


    Duchenne and Becker muscular dystrophies (DMD and BMD) are caused by defects in the dystrophin gene. About two-thirds of the affected patients have large deletions or duplications, which occur in the 5' and central portion of the gene. The nondeletion/duplication cases are most likely the result of smaller mutations that cannot be identified by current diagnostic screening strategies. We screened approximately 80% of the dystrophin coding sequence for small mutations in 158 patients without deletions or duplications and identified 29 mutations. The study indicates that many of the DMD and the majority of the BMD small mutations lie in noncoding regions of the gene. All of the mutations identified were unique to single patients, and most of the mutations resulted in protein truncation. We did not find a clustering of small mutations similar to the deletion distribution but found > 40% of the small mutations 3' of exon 55. The extent of protein truncation caused by the 3' mutations did not determine the phenotype, since even the exon 76 nonsense mutation resulted in the severe DMD phenotype. Our study confirms that the dystrophin gene is subject to a high rate of mutation in CpG sequences. As a consequence of not finding any hotspots or prevalent small mutations, we conclude that it is presently not possible to perform direct carrier and prenatal diagnostics for many families without deletions or duplications.

  2. GBA mutations in Gaucher type I Venezuelan patients: ethnic origins ...

    Indian Academy of Sciences (India)

    Three geographical foci were identified, displaying mutation heterogeneity. N370S had multiple genetic origins, different from the Ashkenazi's; a single common remote ancestor for this mutation in the country was dismissed, according to the haplotype analysis. All mutations have a likely European Caucasoid descent.

  3. Markov chain for estimating human mitochondrial DNA mutation pattern (United States)

    Vantika, Sandy; Pasaribu, Udjianna S.


    The Markov chain was proposed to estimate the human mitochondrial DNA mutation pattern. One DNA sequence was taken randomly from 100 sequences in Genbank. The nucleotide transition matrix and mutation transition matrix were estimated from this sequence. We determined whether the states (mutation/normal) are recurrent or transient. The results showed that both of them are recurrent.

  4. BRCA1 and BRCA2 germline mutation analysis among Indian ...

    Indian Academy of Sciences (India)

    Mutations in the BRCA1 and BRCA2 genes profoundly increase the risk of developing breast and/or ovarian cancer among women. To explore the contribution of BRCA1 and BRCA2 mutations in the development of hereditary breast cancer among Indian women, we carried out mutation analysis of the BRCA1 and BRCA2 ...

  5. A new PAX6 mutation in familial aniridia.


    Hanson, I.; Brown, A.; Van Heyningen, V.


    Aniridia (lack of iris) is caused by loss of function mutations in one copy of the PAX6 gene. Here we present a new PAX6 splice mutation in a family with autosomal dominant aniridia. The mutation is a single nucleotide change which, although occurring within an exon, affects the splice junction consensus and results in skipping of that exon.

  6. Evolutionary invasion and escape in the presence of deleterious mutations.

    Directory of Open Access Journals (Sweden)

    Claude Loverdo

    Full Text Available Replicators such as parasites invading a new host species, species invading a new ecological niche, or cancer cells invading a new tissue often must mutate to adapt to a new environment. It is often argued that a higher mutation rate will favor evolutionary invasion and escape from extinction. However, most mutations are deleterious, and even lethal. We study the probability that the lineage will survive and invade successfully as a function of the mutation rate when both the initial strain and an adaptive mutant strain are threatened by lethal mutations. We show that mutations are beneficial, i.e. a non-zero mutation rate increases survival compared to the limit of no mutations, if in the no-mutation limit the survival probability of the initial strain is smaller than the average survival probability of the strains which are one mutation away. The mutation rate that maximizes survival depends on the characteristics of both the initial strain and the adaptive mutant, but if one strain is closer to the threshold governing survival then its properties will have greater influence. These conclusions are robust for more realistic or mechanistic depictions of the fitness landscapes such as a more detailed viral life history, or non-lethal deleterious mutations.

  7. DNA mutation motifs in the genes associated with inherited diseases. (United States)

    Růžička, Michal; Kulhánek, Petr; Radová, Lenka; Čechová, Andrea; Špačková, Naďa; Fajkusová, Lenka; Réblová, Kamila


    Mutations in human genes can be responsible for inherited genetic disorders and cancer. Mutations can arise due to environmental factors or spontaneously. It has been shown that certain DNA sequences are more prone to mutate. These sites are termed hotspots and exhibit a higher mutation frequency than expected by chance. In contrast, DNA sequences with lower mutation frequencies than expected by chance are termed coldspots. Mutation hotspots are usually derived from a mutation spectrum, which reflects particular population where an effect of a common ancestor plays a role. To detect coldspots/hotspots unaffected by population bias, we analysed the presence of germline mutations obtained from HGMD database in the 5-nucleotide segments repeatedly occurring in genes associated with common inherited disorders, in particular, the PAH, LDLR, CFTR, F8, and F9 genes. Statistically significant sequences (mutational motifs) rarely associated with mutations (coldspots) and frequently associated with mutations (hotspots) exhibited characteristic sequence patterns, e.g. coldspots contained purine tract while hotspots showed alternating purine-pyrimidine bases, often with the presence of CpG dinucleotide. Using molecular dynamics simulations and free energy calculations, we analysed the global bending properties of two selected coldspots and two hotspots with a G/T mismatch. We observed that the coldspots were inherently more flexible than the hotspots. We assume that this property might be critical for effective mismatch repair as DNA with a mutation recognized by MutSα protein is noticeably bent.

  8. BEAMing Up Personalized Medicine: Mutation Detection In Blood


    Richardson, Andrea L.; Iglehart, J. Dirk


    BEAMing is a feasible, accurate and sensitive method for detection of PIK3CA mutations in circulating tumor DNA in blood. Mutation status of PIK3CA may change between primary tumor and recurrence. The results suggest a new approach for non-invasive determination of current mutation status in patients with metastatic disease.

  9. Fitness effects of fixed beneficial mutations in microbial populations

    NARCIS (Netherlands)

    Rozen, D.; Visser, de J.A.G.M.; Gerrish, P.J.


    Beneficial mutations are intuitively relevant to understanding adaptation [1-3], yet not all beneficial mutations are of consequence to the long-term evolutionary outcome of adaptation. Many beneficial mutations - mostly those of small effect - are lost due either to (1) genetic drift [4, 5] or to

  10. Dietary factors and truncating APC mutations in sporadic colorectal adenomas.

    NARCIS (Netherlands)

    Diergaarde, B.; Tiemersma, E.W.; Braam, H.; Muijen, G.N.P. van; Nagengast, F.M.; Kok, F.J.; Kampman, E.


    Inactivating mutations in APC are thought to be early, initiating events in colorectal carcinogenesis. To gain insight into the relationship between diet and inactivating APC mutations, we evaluated associations between dietary factors and the occurrence of these mutations in a Dutch case-control

  11. Dietary factors and Truncating APC Mutations in Sporadic Colorectal Adenomas

    NARCIS (Netherlands)

    Diergaarde, B.; Tiemersma, E.W.; Braam, H.; Muijen, van G.N.P.; Nagengast, F.M.; Kok, F.J.; Kampman, E.


    Inactivating mutations in APC are thought to be early, initiating events in colorectal carcinogenesis. To gain insight into the relationship between diet and inactivating APC mutations, we evaluated associations between dietary factors and the occurrence of these mutations in a Dutch case-control

  12. Splicing aberrations caused by constitutional RB1 gene mutations in ...

    Indian Academy of Sciences (India)

    Analysis of RB1 mRNA from blood leukocytes of patients with retinoblastoma identified the effects of mutations involving consensus splice site, exonic substitution and whole-exon deletions identified in genomic DNA of these patients. In addition, this study identified mutations in cases in which no mutations were detectable ...

  13. Rapid detection of RB1 recurrent mutations in retinoblastoma by ...

    Indian Academy of Sciences (India)

    mutations in RB1 in patients with retinoblastoma. Materials and methods. Subjects. To investigate recurrent mutations of RB1 in retinoblastoma patients, 121 children with sporadic or familial retinoblastoma. Keywords. retinoblastoma; ARMS-PCR; RB1 gene; recurrent mutation. Journal of Genetics Vol. 92, Online Resources.

  14. Diversity of ARSACS mutations in French-Canadians. (United States)

    Thiffault, I; Dicaire, M J; Tetreault, M; Huang, K N; Demers-Lamarche, J; Bernard, G; Duquette, A; Larivière, R; Gehring, K; Montpetit, A; McPherson, P S; Richter, A; Montermini, L; Mercier, J; Mitchell, G A; Dupré, N; Prévost, C; Bouchard, J P; Mathieu, J; Brais, B


    The growing number of spastic ataxia of Charlevoix-Saguenay (SACS) gene mutations reported worldwide has broadened the clinical phenotype of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). The identification of Quebec ARSACS cases without two known SACS mutation led to the development of a multi-modal genomic strategy to uncover mutations in this large gene and explore phenotype variability. Search for SACS mutations by combining various methods on 20 cases with a classical French-Canadian ARSACS phenotype without two mutations and a group of 104 sporadic or recessive spastic ataxia cases of unknown cause. Western blot on lymphoblast protein from cases with different genotypes was probed to establish if they still expressed sacsin. A total of 12 mutations, including 7 novels, were uncovered in Quebec ARSACS cases. The screening of 104 spastic ataxia cases of unknown cause for 98 SACS mutations did not uncover carriers of two mutations. Compounds heterozygotes for one missense SACS mutation were found to minimally express sacsin. The large number of SACS mutations present even in Quebec suggests that the size of the gene alone may explain the great genotypic diversity. This study does not support an expanding ARSACS phenotype in the French-Canadian population. Most mutations lead to loss of function, though phenotypic variability in other populations may reflect partial loss of function with preservation of some sacsin expression. Our results also highlight the challenge of SACS mutation screening and the necessity to develop new generation sequencing methods to ensure low cost complete gene sequencing.

  15. Molecular analyses of novel ASAH1 mutations causing Farber lipogranulomatosis: analyses of exonic splicing enhancer inactivating mutation. (United States)

    Bashyam, M D; Chaudhary, A K; Kiran, M; Reddy, V; Nagarajaram, H A; Dalal, A; Bashyam, L; Suri, D; Gupta, A; Gupta, N; Kabra, M; Puri, R D; RamaDevi, R; Kapoor, S; Danda, S


    Farber lipogranulomatosis is a rare autosomal recessive lysosomal storage disorder caused by mutations in the ASAH1 gene. In the largest ever study, we identified and characterized ASAH1 mutations from 11 independent Farber disease (FD) families. A total of 13 different mutations were identified including 1 splice, 1 polypyrimidine tract (PPT) deletion and 11 missense mutations. Eleven mutations were exclusive to the Indian population. The IVS6+4A>G splice and IVS5-16delTTTTC PPT deletion mutations resulted in skipping of exon 6 precluding thereby the region responsible for cleavage of enzyme precursor. A missense mutation (p.V198A) resulted in skipping of exon 8 due to inactivation of an exonic splicing enhancer (ESE) element. This is the first report of mutations affecting PPT and ESE in the ASAH1 gene resulting in FD. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Expanding the keratin mutation database: novel and recurrent mutations and genotype-phenotype correlations in 28 patients with epidermolytic ichthyosis. (United States)

    Arin, M J; Oji, V; Emmert, S; Hausser, I; Traupe, H; Krieg, T; Grimberg, G


    Epidermolytic ichthyosis (EI) is a hereditary keratinization disorder caused by mutations in the keratin 1 (KRT1) or keratin 10 (KRT10) genes. In most cases of severe EI, heterozygous single point mutations are found at the highly conserved helix boundary motifs of KRT1 and KRT10 that play a critical role in filament formation. The presence of palmoplantar keratoderma suggests KRT1 mutations, whereas KRT10 mutations in most instances give rise to the nonpalmoplantar variants. To identify the underlying mutations in patients with EI and to correlate genotype and phenotype. Mutation analysis was performed in 28 patients with EI by direct sequencing of KRT1 and KRT10 genes. We identified 14 different mutations, of which four have not been published previously. Identification of novel mutations and genotype-phenotype correlations in EI allows improved understanding of disease pathogenesis as well as better patient management. © 2011 The Authors. BJD © 2011 British Association of Dermatologists.

  17. Familial Mediterranean fever with a single MEFV mutation: comparison of rare and common mutations in a Turkish paediatric cohort. (United States)

    Soylemezoglu, Oguz; Kandur, Yasar; Duzova, Ali; Ozkaya, Ozan; Kasapcopur, Ozgür; Baskin, Esra; Fidan, Kibriya; Yalcinkaya, Fatos


    Presence of common MEFV gene mutations strengthened the diagnosis of FMF in addition to the typical clinical characteristics of FMF. However, there are also rare mutations. P369S, A744S, R761H, K695R, F479L are the main rare mutations in Turkish population. We aimed to evaluate FMF patients with a single allele MEFV mutation and to compare patients with common and rare mutations. We retrospectively reviewed the medical records of FMF patients with a single allele mutation who were followed up between 2008 and 2013 in six centres. We compared the patients with rare and common mutations for disease severity score, frequent exacerbations ( >1 attack per month), long attack period (>3 day), symptoms, age at the onset of symptoms, gender, consanguinity, and family history. Two hundred and seventeen patients (M/F=101/116) with the diagnosis of FMF and single mutation were included. Heterozygote mutations were defined as common (M694V, V726A, M68OI) and rare mutations (A744S, P369S, K695R, R761H, F479L). Sixty-seven patients (27 males, 40 females) had one single rare mutation and 150 (74 males, 76 females) had one single common mutation. No difference was found between the rare and common mutations with respect to the disease severity score. There was no significant difference between common and rare heterozygote form of mutations in terms of disease severity. Patients with typical characteristics of FMF, with some rare mutations (A744S, P369S) should be treated in the same manner as patients with a common mutation.

  18. FLT3 mutations in myeloproliferative neoplasms: the Beaumont experience. (United States)

    Williams, Lindsay; Kelley, Harlan H; Meng, Xiuling; Prada, Anne; Crisan, Domnita


    FLT3 is one of the most frequently mutated genes in acute myeloid leukemia. Previous studies have reported FLT3 mutation in as many as 9.2% of myeloproliferative neoplasms (MPNs) and myelodysplastic/myeloproliferative neoplasms (MDS/MPNs), as well as in chronic myelogenous leukemia, that are negative for the JAK2 V617F gene mutation; no FLT3 mutation has been found in JAK2-positive MPNs, suggesting that the mutations are mutually exclusive. The goal of our study is to evaluate the mutational status of the FLT3 gene in patients with an MPN or MDS/MPN, in correlation with the JAK2 mutational status. Patient specimens were retrospectively identified on the basis of MPN or MDS/MPN diagnosis and JAK2 analysis from February 2006 to December 2011. FLT3 mutation analysis was performed on DNA extracted from 152 patients using polymerase chain reaction amplification and analysis of amplicons by gel electrophoresis for internal tandem duplication mutations and by restriction endonuclease digestion fragment analysis for the D835 point mutation. FLT3 mutation analysis was performed on 90 cases of JAK2-negative MPN or MDS/MPN and 62 cases of JAK2-positive MPN. One FLT3 internal tandem duplication mutation was identified in the JAK2-negative group (1.1%), and none were identified in the JAK2-positive group, confirming the absence of FLT3 mutations in JAK2-positive specimens. The FLT3-positive MPN patient was diagnosed with MPN, unclassifiable, and was later found to have myeloid sarcoma; thus, FLT3 mutation was not seen in the usual types of MPN in our series. Our result of 1.1% FLT3 mutations in JAK2-negative MPN and MDS/MPN cases is lower than the 9.2% previously reported.

  19. Sexual selection, germline mutation rate and sperm competition

    Directory of Open Access Journals (Sweden)

    Møller AP


    Full Text Available Abstract Background An important component of sexual selection arises because females obtain viability benefits for their offspring from their mate choice. Females choosing extra-pair fertilization generally favor males with exaggerated secondary sexual characters, and extra-pair paternity increases the variance in male reproductive success. Furthermore, females are assumed to benefit from 'good genes' from extra-pair sires. How additive genetic variance in such viability genes is maintained despite strong directional selection remains an evolutionary enigma. We propose that sexual selection is associated with elevated mutation rates, changing the balance between mutation and selection, thereby increasing variance in fitness and hence the benefits to be obtained from good genes sexual selection. Two hypotheses may account for such elevated mutation: (1 Increased sperm production associated with sperm competition may increase mutation rate. (2 Mutator alleles increase mutation rates that are revealed by the expression of condition-dependent secondary sexual characters used by choosy females during their mate choice. M Petrie has independently developed the idea that mutator alleles may account for the maintenance of genetic variation in viability despite strong directional selection. Results A comparative study of birds revealed a positive correlation between mutation rate at minisatellite loci and extra-pair paternity, but not between mutation rate and relative testes mass which is a measure of relative sperm production. Minisatellite mutation rates were not related to longevity, suggesting a meiotic rather than a mitotic origin of mutations. Conclusion We found evidence of increased mutation rate in species with more intense sexual selection. Increased mutation was not associated with increased sperm production, and we suggest that species with intense sexual selection may maintain elevated mutation rates because sexual selection continuously

  20. Characteristics of gene mutation in Chinese patients with hereditary hemochromatosis

    Directory of Open Access Journals (Sweden)

    LYU Tingxia


    Full Text Available ObjectiveTo investigate the characteristics of gene mutation in Chinese patients with hereditary hemochromatosis (HH. MethodsA total of 9 patients with HH who visited Beijing Friendship Hospital, Capital Medical University from January 2013 to December 2015 were enrolled. The genomic DNA was extracted, and PCR amplification and Sanger sequencing were performed for all the exons of four genotypes of HH, i.e., HFE (type Ⅰ, HJV (type ⅡA, HAMP (type ⅡB, TFR2 (type Ⅲ, and SLC40A1 (type Ⅳ to analyze gene mutations. A total of 50 healthy subjects were enrolled as control group to analyze the prevalence of identified gene mutations in a healthy population. ResultsOf all patients, 2 had H63D mutation of HFE gene in type Ⅰ HH, 1 had E3D mutation of HJV gene in type ⅡA HH, 2 had I238M mutation of TFR2 gene in type Ⅲ HH, and 1 had IVS 3+10 del GTT splice mutation of SLC40A1 gene in type Ⅳ HH. No patients had C282Y mutation of HFE gene in type Ⅰ HH which was commonly seen in European and American populations. Five patients had no missense mutation or splice mutation. In addition, it was found in a family that a HH patient had E3D mutation of HJV gene, H63D mutation of HFE gene, and I238M mutation of TFR2 gene, but the healthy brother and sister carrying two of these mutations did not had the phenotype of HH. ConclusionHH gene mutations vary significantly across patients of different races, and non-HFE-HH is dominant in the Chinese population. There may be HH genes which are different from known genes, and further investigation is needed.

  1. Mitochondrial DNA mutation load in a family with the m.8344A>G point mutation and lipomas

    DEFF Research Database (Denmark)

    Jeppesen, Tina Dysgaard; Al-Hashimi, Noor; Duno, Morten


    Studies have shown that difference in mtDNA mutation load among tissues is a result of postnatal modification. We present five family members with the m.8344A>G with variable phenotypes but uniform intrapersonal distribution of mutation load, indicating that there is no postnatal modification of mt......DNA mutation load in this genotype....

  2. Multiple gene mutations, not the type of mutation, are the modifier of left ventricle hypertrophy in patients with hypertrophic cardiomyopathy. (United States)

    Zou, Yubao; Wang, Jizheng; Liu, Xuan; Wang, Yilu; Chen, Yi; Sun, Kai; Gao, Shuo; Zhang, Channa; Wang, Zhimin; Zhang, Yin; Feng, Xinxing; Song, Ying; Wu, Yajie; Zhang, Hongju; Jia, Lei; Wang, Hu; Wang, Dong; Yan, Chaowu; Lu, Minjie; Zhou, Xianliang; Song, Lei; Hui, Rutai


    Genotype-phenotype correlation of hypertrophic cardiomyopathy (HCM) has been challenging because of the genetic and clinical heterogeneity. To determine the mutation profile of Chinese patients with HCM and to correlate genotypes with phenotypes, we performed a systematic mutation screening of the eight most commonly mutated genes encoding sarcomere proteins in 200 unrelated Chinese adult patients using direct DNA sequencing. A total of 98 mutations were identified in 102 mutation carriers. The frequency of mutations in MYH7, MYBPC3, TNNT2 and TNNI3 was 26.0, 18.0, 4.0 and 3.5 % respectively. Among the 200 genotyped HCM patients, 83 harbored a single mutation, and 19 (9.5 %) harbored multiple mutations. The number of mutations was positively correlated with the maximum wall thickness. We found that neither particular gene nor specific mutation was correlated to clinical phenotype. In summary, the frequency of multiple mutations was greater in Chinese HCM patients than in the Caucasian population. Multiple mutations in sarcomere protein may be a risk factor for left ventricular wall thickness.

  3. [PRRT2 mutation and infantile convulsions]. (United States)

    Mathot, M; Lederer, D; Gerard, S; Gueulette, E; Deprez, M


    New genetic techniques have made it possible to better understand the implications of the PRRT2 gene (proline rich transmembrane protein 2) in various neurological disorders. Mutations within this gene are responsible for kinesigenic paroxysmal dyskinesias (PKD) as well as for benign familial infantile epilepsy (BFIE), a disease associating infantile convulsions and choreoathetosis (ICCA), a form of familial hemiplegic migraine (FHM type 4), paroxysmal benign torticollis of childhood, and episodic ataxia. We describe the case of an infant, carrying a mutation of the PRRT2 gene, with a classical presentation. Through her progression over time, we raise the question of systematic use of anti-epileptic drugs. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. AIRE-mutations and autoimmune disease. (United States)

    Bruserud, Øyvind; Oftedal, Bergithe E; Wolff, Anette B; Husebye, Eystein S


    The gene causing the severe organ-specific autoimmune disease autoimmune polyendocrine syndrome type-1 (APS-1) was identified in 1997 and named autoimmune regulator (AIRE). AIRE plays a key role in shaping central immunological tolerance by facilitating negative selection of T cells in the thymus, building the thymic microarchitecture, and inducing a specific subset of regulatory T cells. So far, about 100 mutations have been identified. Recent advances suggest that certain mutations located in the SAND and PHD1 domains exert a dominant negative effect on wild type AIRE resulting in milder seemingly common forms of autoimmune diseases, including pernicious anemia, vitiligo and autoimmune thyroid disease. These findings indicate that AIRE also contribute to autoimmunity in more common organ-specific autoimmune disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. The Androgen Receptor Gene Mutations Database. (United States)

    Gottlieb, B; Lehvaslaiho, H; Beitel, L K; Lumbroso, R; Pinsky, L; Trifiro, M


    The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 272 to 309 in the past year. We have expanded the database: (i) by giving each entry an accession number; (ii) by adding information on the length of polymorphic polyglutamine (polyGln) and polyglycine (polyGly) tracts in exon 1; (iii) by adding information on large gene deletions; (iv) by providing a direct link with a completely searchable database (courtesy EMBL-European Bioinformatics Institute). The addition of the exon 1 polymorphisms is discussed in light of their possible relevance as markers for predisposition to prostate or breast cancer. The database is also available on the internet (http://www.mcgill. ca/androgendb/ ), from EMBL-European Bioinformatics Institute (ftp. ), or as a Macintosh FilemakerPro or Word file (

  6. The Androgen Receptor Gene Mutations Database. (United States)

    Gottlieb, B; Lehvaslaiho, H; Beitel, L K; Lumbroso, R; Pinsky, L; Trifiro, M


    The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 272 to 309 in the past year. We have expanded the database: (i) by giving each entry an accession number; (ii) by adding information on the length of polymorphic polyglutamine (polyGln) and polyglycine (polyGly) tracts in exon 1; (iii) by adding information on large gene deletions; (iv) by providing a direct link with a completely searchable database (courtesy EMBL-European Bioinformatics Institute). The addition of the exon 1 polymorphisms is discussed in light of their possible relevance as markers for predisposition to prostate or breast cancer. The database is also available on the internet (http://www.mcgill. ca/androgendb/ ), from EMBL-European Bioinformatics Institute (ftp. ), or as a Macintosh FilemakerPro or Word file ( PMID:9399843

  7. Expanding the clinical and mutational spectrum of Kaufman oculocerebrofacial syndrome with biallelic UBE3B mutations. (United States)

    Basel-Vanagaite, Lina; Yilmaz, Rüstem; Tang, Sha; Reuter, Miriam S; Rahner, Nils; Grange, Dorothy K; Mortenson, Megan; Koty, Patrick; Feenstra, Heather; Farwell Gonzalez, Kelly D; Sticht, Heinrich; Boddaert, Nathalie; Désir, Julie; Anyane-Yeboa, Kwame; Zweier, Christiane; Reis, André; Kubisch, Christian; Jewett, Tamison; Zeng, Wenqi; Borck, Guntram


    Biallelic mutations of UBE3B have recently been shown to cause Kaufman oculocerebrofacial syndrome (also reported as blepharophimosis-ptosis-intellectual disability syndrome), an autosomal recessive condition characterized by hypotonia, developmental delay, intellectual disability, congenital anomalies, characteristic facial dysmorphic features, and low cholesterol levels. To date, six patients with either missense mutations affecting the UBE3B HECT domain or truncating mutations have been described. Here, we report on the identification of homozygous or compound heterozygous UBE3B mutations in six additional patients from five unrelated families using either targeted UBE3B sequencing in individuals with suggestive facial dysmorphic features, or exome sequencing. Our results expand the clinical and mutational spectrum of the UBE3B-related disorder in several ways. First, we have identified UBE3B mutations in individuals who previously received distinct clinical diagnoses: two sibs with Toriello-Carey syndrome as well as the patient reported to have a "new" syndrome by Buntinx and Majewski in 1990. Second, we describe the adult phenotype and clinical variability of the syndrome. Third, we report on the first instance of homozygous missense alterations outside the HECT domain of UBE3B, observed in a patient with mildly dysmorphic facial features. We conclude that UBE3B mutations cause a clinically recognizable and possibly underdiagnosed syndrome characterized by distinct craniofacial features, hypotonia, failure to thrive, eye abnormalities, other congenital malformations, low cholesterol levels, and severe intellectual disability. We review the UBE3B-associated phenotypes, including forms that can mimick Toriello-Carey syndrome, and suggest the single designation "Kaufman oculocerebrofacial syndrome".

  8. Mutation scanning of peach floral genes

    Directory of Open Access Journals (Sweden)

    Wilde H Dayton


    Full Text Available Abstract Background Mutation scanning technology has been used to develop crop species with improved traits. Modifications that improve screening throughput and sensitivity would facilitate the targeted mutation breeding of crops. Technical innovations for high-resolution melting (HRM analysis are enabling the clinic-based screening for human disease gene polymorphism. We examined the application of two HRM modifications, COLD-PCR and QMC-PCR, to the mutation scanning of genes in peach, Prunus persica. The targeted genes were the putative floral regulators PpAGAMOUS and PpTERMINAL FLOWER I. Results HRM analysis of PpAG and PpTFL1 coding regions in 36 peach cultivars found one polymorphic site in each gene. PpTFL1 and PpAG SNPs were used to examine approaches to increase HRM throughput. Cultivars with SNPs could be reliably detected in pools of twelve genotypes. COLD-PCR was found to increase the sensitivity of HRM analysis of pooled samples, but worked best with small amplicons. Examination of QMC-PCR demonstrated that primary PCR products for further analysis could be produced from variable levels of genomic DNA. Conclusions Natural SNPs in exons of target peach genes were discovered by HRM analysis of cultivars from a southeastern US breeding program. For detecting natural or induced SNPs in larger populations, HRM efficiency can be improved by increasing sample pooling and template production through approaches such as COLD-PCR and QMC-PCR. Technical advances developed to improve clinical diagnostics can play a role in the targeted mutation breeding of crops.

  9. ELOVL5 mutations cause spinocerebellar ataxia 38. (United States)

    Di Gregorio, Eleonora; Borroni, Barbara; Giorgio, Elisa; Lacerenza, Daniela; Ferrero, Marta; Lo Buono, Nicola; Ragusa, Neftj; Mancini, Cecilia; Gaussen, Marion; Calcia, Alessandro; Mitro, Nico; Hoxha, Eriola; Mura, Isabella; Coviello, Domenico A; Moon, Young-Ah; Tesson, Christelle; Vaula, Giovanna; Couarch, Philippe; Orsi, Laura; Duregon, Eleonora; Papotti, Mauro Giulio; Deleuze, Jean-François; Imbert, Jean; Costanzi, Chiara; Padovani, Alessandro; Giunti, Paola; Maillet-Vioud, Marcel; Durr, Alexandra; Brice, Alexis; Tempia, Filippo; Funaro, Ada; Boccone, Loredana; Caruso, Donatella; Stevanin, Giovanni; Brusco, Alfredo


    Spinocerebellar ataxias (SCAs) are a heterogeneous group of autosomal-dominant neurodegenerative disorders involving the cerebellum and 23 different genes. We mapped SCA38 to a 56 Mb region on chromosome 6p in a SCA-affected Italian family by whole-genome linkage analysis. Targeted resequencing identified a single missense mutation (c.689G>T [p.Gly230Val]) in ELOVL5. Mutation screening of 456 independent SCA-affected individuals identified the same mutation in two further unrelated Italian families. Haplotyping showed that at least two of the three families shared a common ancestor. One further missense variant (c.214C>G [p.Leu72Val]) was found in a French family. Both missense changes affect conserved amino acids, are predicted to be damaging by multiple bioinformatics tools, and were not identified in ethnically matched controls or within variant databases. ELOVL5 encodes an elongase involved in the synthesis of polyunsaturated fatty acids of the ω3 and ω6 series. Arachidonic acid and docosahexaenoic acid, two final products of the enzyme, were reduced in the serum of affected individuals. Immunohistochemistry on control mice and human brain demonstrated high levels in Purkinje cells. In transfection experiments, subcellular localization of altered ELOVL5 showed a perinuclear distribution with a signal increase in the Golgi compartment, whereas the wild-type showed a widespread signal in the endoplasmic reticulum. SCA38 and SCA34 are examples of SCAs due to mutations in elongase-encoding genes, emphasizing the importance of fatty-acid metabolism in neurological diseases. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  10. Oncogenic mutations of ALK kinase in neuroblastoma. (United States)

    Chen, Yuyan; Takita, Junko; Choi, Young Lim; Kato, Motohiro; Ohira, Miki; Sanada, Masashi; Wang, Lili; Soda, Manabu; Kikuchi, Akira; Igarashi, Takashi; Nakagawara, Akira; Hayashi, Yasuhide; Mano, Hiroyuki; Ogawa, Seishi


    Neuroblastoma in advanced stages is one of the most intractable paediatric cancers, even with recent therapeutic advances. Neuroblastoma harbours a variety of genetic changes, including a high frequency of MYCN amplification, loss of heterozygosity at 1p36 and 11q, and gain of genetic material from 17q, all of which have been implicated in the pathogenesis of neuroblastoma. However, the scarcity of reliable molecular targets has hampered the development of effective therapeutic agents targeting neuroblastoma. Here we show that the anaplastic lymphoma kinase (ALK), originally identified as a fusion kinase in a subtype of non-Hodgkin's lymphoma (NPM-ALK) and more recently in adenocarcinoma of lung (EML4-ALK), is also a frequent target of genetic alteration in advanced neuroblastoma. According to our genome-wide scans of genetic lesions in 215 primary neuroblastoma samples using high-density single-nucleotide polymorphism genotyping microarrays, the ALK locus, centromeric to the MYCN locus, was identified as a recurrent target of copy number gain and gene amplification. Furthermore, DNA sequencing of ALK revealed eight novel missense mutations in 13 out of 215 (6.1%) fresh tumours and 8 out of 24 (33%) neuroblastoma-derived cell lines. All but one mutation in the primary samples (12 out of 13) were found in stages 3-4 of the disease and were harboured in the kinase domain. The mutated kinases were autophosphorylated and displayed increased kinase activity compared with the wild-type kinase. They were able to transform NIH3T3 fibroblasts as shown by their colony formation ability in soft agar and their capacity to form tumours in nude mice. Furthermore, we demonstrate that downregulation of ALK through RNA interference suppresses proliferation of neuroblastoma cells harbouring mutated ALK. We anticipate that our findings will provide new insights into the pathogenesis of advanced neuroblastoma and that ALK-specific kinase inhibitors might improve its clinical outcome.

  11. Distinct pattern of p53 mutations in bladder cancer

    DEFF Research Database (Denmark)

    Spruck, C H; Rideout, W M; Olumi, A F


    double mutations, four of which were tandem mutations on the same allele. No double mutations were found in tumors from nonsmoking patients. None of the mutations in smokers were G:C-->T:A transversions, which would be anticipated for exposure to the suspected cigarette smoke carcinogen 4-aminobiphenyl....... The results suggest that, although cigarette smoke exposure may not significantly alter the kinds of mutations sustained in the p53 gene, it may act to increase the extent of DNA damage per mutagenic event....

  12. Persistence of HIV-1 Transmitted Drug Resistance Mutations (United States)

    Castro, Hannah; Pillay, Deenan; Cane, Patricia; Asboe, David; Cambiano, Valentina; Phillips, Andrew; Dunn, David T.; Aitken, Celia; Asboe, David; Webster, Daniel; Cane, Patricia; Castro, Hannah; Chadwick, David; Churchill, Duncan; Clark, Duncan; Collins, Simon; Delpech, Valerie; Geretti, Anna Maria; Goldberg, David; Hale, Antony; Hué, Stéphane; Kaye, Steve; Kellam, Paul; Lazarus, Linda; Leigh-Brown, Andrew; Mackie, Nicola; Orkin, Chloe; Rice, Philip; Pillay, Deenan; Smit, Erasmus; Templeton, Kate; Tilston, Peter; Tong, William; Williams, Ian; Zhang, Hongyi; Zuckerman, Mark; Greatorex, Jane; Wildfire, Adrian; O'Shea, Siobhan; Mullen, Jane; Mbisa, Tamyo; Cox, Alison; Tandy, Richard; Hale, Tony; Fawcett, Tracy; Hopkins, Mark; Ashton, Lynn; Garcia-Diaz, Ana; Shepherd, Jill; Schmid, Matthias L; Payne, Brendan; Chadwick, David; Hay, Phillip; Rice, Phillip; Paynter, Mary; Clark, Duncan; Bibby, David; Kaye, Steve; Kirk, Stuart; MacLean, Alasdair; Aitken, Celia; Gunson, Rory


    There are few data on the persistence of individual human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) mutations in the absence of selective drug pressure. We studied 313 patients in whom TDR mutations were detected at their first resistance test and who had a subsequent test performed while ART-naive. The rate at which mutations became undetectable was estimated using exponential regression accounting for interval censoring. Most thymidine analogue mutations (TAMs) and T215 revertants (but not T215F/Y) were found to be highly stable, with NNRTI and PI mutations being relatively less persistent. Our estimates are important for informing HIV transmission models. PMID:23904291

  13. MUTbase: maintenance and analysis of distributed mutation databases. (United States)

    Riikonen, P; Vihinen, M


    To develop tools for the submission of mutations to databases and maintenance of locus-specific mutation databases. Advanced, integrated computer systems are needed to store and organize the increasing mutation information. The MUTbase program suite provides an easy, interactive and quality-controlled submission of information to mutation databases. For further study of the databases on the World Wide Web, a number of tools are provided. The program package also writes and updates a large number of Web pages, e.g. about the distribution and statistics of disease-causing mutations, and changes in restriction patterns.

  14. Prospects for cellular mutational assays in human populations

    Energy Technology Data Exchange (ETDEWEB)

    Mendelsohn, M.L.


    Practical, sensitive, and effective human cellular assays for detecting somatic and germinal mutations would have great value in environmental mutagenesis and carcinogenesis studies. Such assays would fill the void between human mutagenicity and the data that exist from short-term tests and from mutagenicity in other species. This paper discusses the following possible human cellular assays: (1) HPRT (hypoxanthine phosphoribosyltransferase) somatic cell mutation based on 6-thioguanine resistance; (2) hemoglobin somatic cell mutation assay; (3) glycophorin somatic cell mutation assay; and (4) LDH-X sperm cell mutation assay. 18 references.

  15. Human diseases associated with GPR54 mutations. (United States)

    Teles, Milena Gurgel; Silveira, Leticia Ferreira Gontijo; Bianco, Suzy; Latronico, Ana Claudia


    G protein-coupled receptor 54 (GPR54) was first described as an orphan receptor in the rat brain one decade ago. At that time, all we knew about this receptor was that it had a high homology with other G protein-coupled receptors, like galanin receptors. Later, its endogenous ligand, kisspeptin, was identified and the kisspeptin-GPR54 system became one of the most important excitatory neuroendocrine regulators of puberty initiation. Several loss-of-function mutations in GPR54 gene were described to be associated with sporadic and familial normosmic isolated hypogonadotropic hypogonadism phenotype in humans. Consistent with this fact, knockout mice for gpr54(-/-) recapitulated the human phenotype of the lack of reproductive maturation. On the other hand, a unique activating mutation (R386P) was recently described in this receptor in a girl with central precocious puberty. This missense mutation located at carboxy-terminal tail of the GPR54 leads to prolonged activation of intracellular signaling pathways in response to kisspeptin, suggesting an uncommon model of G protein-coupled receptor activation. This chapter will describe the kisspeptin-GPR54 complex physiology and its current role in human diseases. Copyright © 2009 Elsevier Inc. All rights reserved.

  16. Enhanced tumorigenicity by mitochondrial DNA mild mutations. (United States)

    Cruz-Bermúdez, Alberto; Vallejo, Carmen G; Vicente-Blanco, Ramiro J; Gallardo, María Esther; Fernández-Moreno, Miguel Ángel; Quintanilla, Miguel; Garesse, Rafael


    To understand how mitochondria are involved in malignant transformation we have generated a collection of transmitochondrial cybrid cell lines on the same nuclear background (143B) but with mutant mitochondrial DNA (mtDNA) variants with different degrees of pathogenicity. These include the severe mutation in the tRNALys gene, m.8363G>A, and the three milder yet prevalent Leber's hereditary optic neuropathy (LHON) mutations in the MT-ND1 (m.3460G>A), MT-ND4 (m.11778G>A) and MT-ND6 (m.14484T>C) mitochondrial genes. We found that 143B ρ0 cells devoid of mtDNA and cybrids harboring wild type mtDNA or that causing severe mitochondrial dysfunction do not produce tumors when injected in nude mice. By contrast cybrids containing mild mutant mtDNAs exhibit different tumorigenic capacities, depending on OXPHOS dysfunction.The differences in tumorigenicity correlate with an enhanced resistance to apoptosis and high levels of NOX expression. However, the final capacity of the different cybrid cell lines to generate tumors is most likely a consequence of a complex array of pro-oncogenic and anti-oncogenic factors associated with mitochondrial dysfunction.Our results demonstrate the essential role of mtDNA in tumorigenesis and explain the numerous and varied mtDNA mutations found in human tumors, most of which give rise to mild mitochondrial dysfunction.

  17. Hereditary sideroblastic anemia: pathophysiology and gene mutations. (United States)

    Harigae, Hideo; Furuyama, Kazumichi


    Sideroblastic anemia is characterized by anemia with the emergence of ring sideroblasts in the bone marrow. Ring sideroblasts are erythroblasts characterized by iron accumulation in perinuclear mitochondria due to impaired iron utilization. There are two forms of sideroblastic anemia, i.e., inherited and acquired sideroblastic anemia. Inherited sideroblastic anemia is a rare and heterogeneous disease caused by mutations of genes involved in heme biosynthesis, iron-sulfur (Fe-S) cluster biogenesis, or Fe-S cluster transport, and mitochondrial metabolism. The most common inherited sideroblastic anemia is X-linked sideroblastic anemia (XLSA) caused by mutations of the erythroid-specific δ-aminolevulinate synthase gene (ALAS2), which is the first enzyme of heme biosynthesis in erythroid cells. Sideroblastic anemia due to SLC25A38 gene mutations, which is a mitochondrial transporter, is the next most common inherited sideroblastic anemia. Other forms of inherited sideroblastic anemia are very rare, and accompanied by impaired function of organs other than hematopoietic tissue, such as the nervous system, muscle, or exocrine glands due to impaired mitochondrial metabolism. Moreover, there are still significant numbers of cases with genetically undefined inherited sideroblastic anemia. Molecular analysis of these cases will contribute not only to the development of effective treatment, but also to the understanding of mitochondrial iron metabolism.

  18. Plant Breeding by Using Radiation Mutation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Si Yong; Kim, Dong Sub; Lee, Geung Joo (and others)


    A mutation breeding is to use physical or chemical mutagens to induce mutagenesis, followed by individual selections with favorable traits. The mutation breeding has many advantages over other breeding methods, which include the usefulness for improving one or two inferior characteristics, applications to broad species with different reproductive systems or to diverse plant materials, native or plant introduction with narrow genetic background, time and cost-effectiveness, and valuable mutant resources for genomic researches. Recent applications of the radiation breeding techniques to developments of flowering plants or food crops with improved functional constituents heightened the public's interests in agriculture and in our genetic resources and seed industries. The goals of this project, therefore, include achieving advances in domestic seed industries and agricultural productivities by developing and using new radiation mutants with favored traits, protecting an intellectual property right of domestic seeds or germplasm, and sharing the valuable mutants and mutated gene information for the genomic and biotech researches that eventually leads to economic benefits.

  19. Painful peripheral neuropathy and sodium channel mutations. (United States)

    Hoeijmakers, Janneke G J; Faber, Catharina G; Merkies, Ingemar S J; Waxman, Stephen G


    Peripheral neuropathy can lead to neuropathic pain in a subset of patients. Painful peripheral neuropathy is a debilitating disorder, reflected by a reduced quality of life. Therapeutic strategies are limited and often disappointing, as in most cases targeted treatment is not available. Elucidating pathogenetic factors for pain might provide a target for optimal treatment. Voltage-gated sodium channels NaV1.7-NaV1.9 are expressed in the small-diameter dorsal root ganglion neurons and their axons. By a targeted gene approach, missense gain-of-function mutations of NaV1.7-NaV1.9 have been demonstrated in painful peripheral neuropathy. Functional analyses have shown that these mutations produce a spectrum of pro-excitatory changes in channel biophysics, with the shared outcome at the cellular level of dorsal root ganglion hyperexcitability. Reduced neurite outgrowth may be another consequence of sodium channel mutations, and possible therapeutic strategies include blockade of sodium channels or block of reverse operation of the sodium-calcium exchanger. Increased understanding of the pathophysiology of painful peripheral neuropathy offers new targets that may provide a basis for more effective treatment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Weaver syndrome and EZH2 mutations: Clarifying the clinical phenotype. (United States)

    Tatton-Brown, Katrina; Murray, Anne; Hanks, Sandra; Douglas, Jenny; Armstrong, Ruth; Banka, Siddharth; Bird, Lynne M; Clericuzio, Carol L; Cormier-Daire, Valerie; Cushing, Tom; Flinter, Frances; Jacquemont, Marie-Line; Joss, Shelagh; Kinning, Esther; Lynch, Sally Ann; Magee, Alex; McConnell, Vivienne; Medeira, Ana; Ozono, Keiichi; Patton, Michael; Rankin, Julia; Shears, Debbie; Simon, Marleen; Splitt, Miranda; Strenger, Volker; Stuurman, Kyra; Taylor, Clare; Titheradge, Hannah; Van Maldergem, Lionel; Temple, I Karen; Cole, Trevor; Seal, Sheila; Rahman, Nazneen


    Weaver syndrome, first described in 1974, is characterized by tall stature, a typical facial appearance, and variable intellectual disability. In 2011, mutations in the histone methyltransferase, EZH2, were shown to cause Weaver syndrome. To date, we have identified 48 individuals with EZH2 mutations. The mutations were primarily missense mutations occurring throughout the gene, with some clustering in the SET domain (12/48). Truncating mutations were uncommon (4/48) and only identified in the final exon, after the SET domain. Through analyses of clinical data and facial photographs of EZH2 mutation-positive individuals, we have shown that the facial features can be subtle and the clinical diagnosis of Weaver syndrome is thus challenging, especially in older individuals. However, tall stature is very common, reported in >90% of affected individuals. Intellectual disability is also common, present in ~80%, but is highly variable and frequently mild. Additional clinical features which may help in stratifying individuals to EZH2 mutation testing include camptodactyly, soft, doughy skin, umbilical hernia, and a low, hoarse cry. Considerable phenotypic overlap between Sotos and Weaver syndromes is also evident. The identification of an EZH2 mutation can therefore provide an objective means of confirming a subtle presentation of Weaver syndrome and/or distinguishing Weaver and Sotos syndromes. As mutation testing becomes increasingly accessible and larger numbers of EZH2 mutation-positive individuals are identified, knowledge of the clinical spectrum and prognostic implications of EZH2 mutations should improve. © 2013 Wiley Periodicals, Inc.