bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying components of risk for European woody species under climate change
Authors: OHLEMÜLLER RALF , GRITTI EMMANUEL S. , SYKES MARTIN T. , THOMAS CHRIS D. 
Published: August 2006

AbstractEstimates of species extinction risk under climate change are generally based on differences in present and future climatically suitable areas. However, the locations of potentially suitable future environments (affecting establishment success), and the degree of climatic suitability in already occupied and new locations (affecting population viability) may be equally important determinants of risk. A species considered to be at low risk because its future distribution is predicted to be large, may actually be at high risk if these areas are out of reach, given the species' dispersal and migration rates or if all future suitable locations are only marginally suitable and the species is unlikely to build viable populations in competition with other species. Using bioclimatic models of 17 representative European woody species, we expand on current ways of risk assessment and suggest additional measures based on (a) the distance between presently occupied areas and areas predicted to be climatically suitable in the future and (b) the degree of change in climatic suitability in presently occupied and unoccupied locations. Species of boreal and temperate deciduous forests are predicted to face higher risk from loss of climatically suitable area than species from warmer and drier parts of Europe by 2095 using both the moderate B1 and the severe A1FI emission scenario. However, the average distance from currently occupied locations to areas predicted suitable in the future is generally shorter for boreal species than for southern species. Areas currently occupied will become more suitable for boreal and temperate species than for Mediterranean species whereas new suitable areas outside a species' current range are expected to show greater increases in suitability for Mediterranean species than for boreal and temperate species. Such additional risk measures can be easily derived and should give a more comprehensive picture of the risk species are likely to face under climate change.
Analysis of fat body transcriptome from the adult tsetse fly, Glossina morsitans morsitans
Authors: Attardo G. M. , Strickler‐Dinglasan P. , Perkin S. A. H. , Caler E. , Bonaldo M. F. , Soares M. B. , El‐Sayeed N. , Aksoy S. 
Published: August 2006

AbstractTsetse flies (Diptera: Glossinidia) are vectors of pathogenic African trypanosomes. To develop a foundation for tsetse physiology, a normalized expressed sequence tag (EST) library was constructed from fat body tissue of immune‐stimulated Glossina morsitans morsitans. Analysis of 20 257 high‐quality ESTs yielded 6372 unique genes comprised of 3059 tentative consensus (TC) sequences and 3313 singletons (available at http://aksoylab.yale.edu). We analysed the putative fat body transcriptome based on homology to other gene products with known functions available in the public domain. In particular, we describe the immune‐related products, reproductive function related yolk proteins and milk‐gland protein, iron metabolism regulating ferritins and transferrin, and tsetse's major energy source proline biosynthesis. Expression analysis of the three yolk proteins indicates that all are detected in females, while only the yolk protein with similarity to lipases, is expressed in males. Milk gland protein, apparently important for larval nutrition, however, is primarily synthesized by accessory milk gland tissue.
Differential expression of two glutathione S‐transferases identified from the American dog tick,Dermacentor variabilis
Authors: Dreher‐Lesnick S. M. , Mulenga A. , Simser J. A. , Azad A. F. 
Published: August 2006

AbstractReciprocal signalling and gene expression play a cardinal role during pathogen–host molecular interactions and are prerequisite to the maintenance of balanced homeostasis. Gene expression repertoire changes during rickettsial infection and glutathione‐S‐transferases (GSTs) were among the genes found up‐regulated inRickettsia‐infectedDermacentor variabilis. GSTs are well known to play an important part in cellular stress responses in the host. We have cloned two full‐length GSTs fromD. variabilis(DvGST1 and DvGST2). Comparison of these two DvGST molecules with those of other species indicate that DvGST1 is related to the mammalian class theta and insect class delta GSTs, while DvGST2 does not seem to fall in the same family. Northern blotting analyses revealed differential expression patterns, where DvGST1 and DvGST2 transcripts are found in the tick gut, with DvGST2 transcripts also present in the ovaries. Both DvGST transcripts are up‐regulated upon tick feeding. Challenge of fed adult ticks withEscherichia coliinjection showed decreased transcript amounts compared with ticks injected with phosphate‐buffered saline (sham) and naïve ticks.
A female‐specific desaturase gene responsible for diene hydrocarbon biosynthesis and courtship behaviour in Drosophila melanogaster
Authors: Chertemps T. , Duportets L. , Labeur C. , Ueyama M. , Wicker‐Thomas C. 
Published: August 2006

Abstract Drosophila melanogaster shows sexually dimorphic cuticular hydrocarbons, with monoenes produced in males and dienes produced in females. Here we describe a female‐specific desaturase gene, desatF. RNAi knock‐down led to a dramatic decrease in female dienes and increase in monoenes paralleled with an increase in copulation latency and a decrease in courtship index and copulation attempts by the males. The desatF gene was also expressed in females from D. sechellia, rich in dienes, but not D. simulans, which produce only monoenes. When hydrocarbons were feminized in D. melanogaster males by targeted expression of the transformer gene, the expression of desatF occurred. These results strongly suggest that desatF is a crucial enzyme for female pheromone biosynthesis and courtship behaviour in D. melanogaster.
Cloning and characterization of protease inhibitor‐like cDNAs from the Hessian fly mayetiola destructor (SAY)
Authors: Maddur A. A. , Liu X. , Zhu Y. C. , Fellers J. P. , Oppert B. , Park Y. , Bai J. , Wilde G. E. , Chen M.‐S. 
Published: August 2006

AbstractAnalysis of transcriptomes from the salivary glands and midgut of Hessian fly larvae Mayetiola destructor (say) identified a set of diverse cDNAs that encode proteins with a relatively high percentage (over 10%) of cysteinyl residues. Structural comparison of these putative proteins with known sequences in GenBank revealed that the positions of the cysteinyl residues in the identified proteins were highly conserved within a family of proteinase inhibitors despite very little overall sequence similarity. Phylogenetic analysis sorted this set of cDNAs into five different groups. To determine if these cDNAs indeed encode proteinase inhibitors, recombinant proteins were generated with two cDNAs from two different groups. Biochemical analysis of the recombinant proteins against commercial and insect gut proteinases demonstrated that the recombinant proteins are strong proteinase inhibitors with different specificities. Northern blot and real‐time PCR analysis revealed that the different genes were expressed at different developmental stages and in different tissues. The overall results indicated that M. destructor contains a complex of genes that code for proteinase inhibitors which may regulate proteinase activities in different regulatory pathways. The GenBank accession numbers for the cDNAs in this paper were DQ232690 to DQ232718.
A tapeworm molecule manipulates vitellogenin expression in the beetle Tenebrio molitor
Authors: Warr E. , Meredith J. M. , Nimmo D. D. , Basu S. , Hurd H. , Eggleston P. 
Published: August 2006

AbstractMetacestodes of Hymenolepis diminuta secrete a molecule that decreases vitellogenin (Vg) synthesis in the beetle host, Tenebrio molitor. The 5608 bp T. molitor Vg cDNA represents a single‐copy gene encoding a single open reading frame of 1821 amino acids with a predicted molecular mass of 206 kDa. Northern blot analysis revealed detectable levels of transcripts only in adult females. In vivo, Vg mRNA abundance was significantly higher in fat bodies from infected females compared with control females at all but the earliest time point. In vitro, Vg mRNA abundance was significantly increased in fat bodies incubated with live stage I–II parasites. The apparent conflict between increased Vg mRNA abundance and decreased Vg protein in fat bodies from infected females is discussed.
High yield and rapid growth of Neoparamoeba pemaquidensis in co‐culture with a rainbow trout gill‐derived cell line RTgill‐W1
Authors: Lee L E J , Van Es S J , Walsh S K , Rainnie D J , Donay N , Summerfield R , Cawthorn R J 
Published: August 2006

Abstract Neoparamoeba pemaquidensis is an ubiquitous amphizoic marine protozoan and has been implicated as the causative agent for several diseases in marine organisms, most notably amoebic gill disease (AGD) in Atlantic salmon. Despite several reports on the pathology of AGD, relatively little is known about the protozoan and its relationship to host cells. In this study, an in vitro approach using monolayers of a rainbow trout gill cell line (RTgill‐W1, ATCC CRL‐2523) was used to rapidly grow large numbers of N. pemaquidensis (ATCC 50172) and investigate cell–pathogen interactions. Established cell lines derived from other tissues of rainbow trout and other fish species were also evaluated for amoeba growth support. The amoebae showed preference and highest yield when grown with RTgill‐W1 over nine other tested fish cell lines. Amoeba yields could reach as high as 5 × 105 cells mL−1 within 3 days of growth on the gill cell monolayers. The amoebae caused visible focal lesions in RTgill‐W1 monolayers within 24 h of exposure and rapidly proliferated and spread with cytopathic effects destroying the neighbouring pavement‐like cells within 48–72 h after initial exposure in media above 700 mOsm kg−1. Disruption of the integrity of the gill cell monolayers could be noted within 30 min of exposure to the amoeba suspensions by changes in transepithelial resistance (TER) compared with control cell monolayers maintained in the exposure media. This was significantly different by 2 h (P < 0.05) compared with control cells and remained significantly different (P < 0.01) for the remaining 72 h that the TER was monitored. The RTgill‐W1 cell line is thus a convenient model for growing N. pemaquidensis and for studying host–pathogen interactions in AGD.
Towards unbiased parentage assignment: combining genetic, behavioural and spatial data in a Bayesian framework
Authors: HADFIELD J. D. , RICHARDSON D. S. , BURKE T. 
Published: August 2006

AbstractInferring the parentage of a sample of individuals is often a prerequisite for many types of analysis in molecular ecology, evolutionary biology and quantitative genetics. In all but a few cases, the method of parentage assignment is divorced from the methods used to estimate the parameters of primary interest, such as mate choice or heritability. Here we present a Bayesian approach that simultaneously estimates the parentage of a sample of individuals and a wide range of population‐level parameters in which we are interested. We show that joint estimation of parentage and population‐level parameters increases the power of parentage assignment, reduces bias in parameter estimation, and accurately evaluates uncertainty in both. We illustrate the method by analysing a number of simulated test data sets, and through a re‐analysis of parentage in the Seychelles warbler, Acrocephalus sechellensis. A combination of behavioural, spatial and genetic data are used in the analyses and, importantly, the method does not require strong prior information about the relationship between nongenetic data and parentage.
FibA and PilA act cooperatively during fruiting body formation of Myxococcus xanthus
Authors: Bonner Pamela J. , Black Wesley P. , Yang Zhaomin , Shimkets Lawrence J. 
Published: August 2006

SummaryThe extracellular matrix (ECM) of Myxococcus xanthus is essential for social (S‐) motility and fruiting body formation. An ECM‐bound protein, FibA, is homologous to M4 zinc metalloproteases and is important for stimulation by a phosphatidylethanolamine (PE) chemoattractant and for formation of discrete aggregation foci. In this work, we demonstrate that a correlation exists between a reduced ability to respond to PE and the observed defects in fruiting body morphogenesis. Furthermore, the fibA aggregation defect is accentuated by the absence of either PilA, the structural subunit of type IV pili, or DifD, a chemosensory response regulator. The inability to form fruiting bodies is not due to a loss of S‐motility, but rather the loss of PilA and pili as pilT fibA mutants form fruiting bodies. The FibA active site residue E342 is important for fruiting body morphogenesis in the absence of PilA. Mutants exhibiting defects in fruiting body morphogenesis also produce fewer viable spores. It is proposed that FibA and PilA act as extracellular sensors for developmental signals.
rag genes: novel components of the RamR regulon that trigger morphological differentiation in Streptomyces coelicolor
Authors: Paolo Salvatore San , Huang Jianqiang , Cohen Stanley N. , Thompson Charles J. 
Published: August 2006

SummaryThe filamentous bacterium, Streptomyces coelicolor, undergoes a complex cycle of growth and development in which morphological differentiation coincides with the activation of the orphan response regulator RamR and the biosynthesis of a morphogenic peptide called SapB. SapB is a lantibiotic‐like molecule derived from the product of the ramS gene that promotes formation of aerial hyphae by breaking the aqueous tension on the surface of the substrate mycelium. A ramR‐disrupted mutant is delayed in aerial hyphae formation while constitutive overexpression of ramR accelerates aerial hyphae formation in the wild‐type strain and restores SapB biosynthesis and aerial hyphae formation in all developmental mutants (bld) tested. Using DNA microarrays to globally identify S. coelicolor genes whose transcription was affected by ramR mutation or overexpression, we discovered a ramR‐activated locus of contiguous cotranscribed developmental genes that modulate both aerial hyphae formation and sporulation. The genes of this cluster of ramR‐activated genes (rag), which are chromosomally distant from previously known RamR‐regulated genes, include: ragA (sco4075) and ragB (sco4074), which encode two subunits of an ABC transporter, ragK (sco4073), a putative histidine kinase, and ragR (sco4072), a ramR paralogue. Promoter mapping and protein–DNA binding experiments indicate that RamR activates ragABKR transcription directly, by binding to three sequence motifs in the ragABKR promoter region. A constructed ragABKR null mutant was able to synthesize SapB and erect aerial hyphae; however, these hyphae were unusually branched, reminiscent of substrate hyphae. Subsequent stages of differentiation, septation and sporogenesis were delayed. The role of ragABKR in aerial hyphae formation was shown both by epistasis (ragR‐activated aerial hyphae formation in bld mutants) and extracellular complementation (ragR‐induced synthesis of an activity allowing aerial hyphae formation in bld mutants) experiments. In conclusion, the ragABKR locus activates a SapB‐independent developmental pathway that is involved in both aerial hyphae formation and sporulation, serving to integrate sequential morphogenic changes.
Phospholipid directed motility of surface‐motile bacteria
Authors: Bonner Pamela J. , Shimkets Lawrence J. 
Published: August 2006

Summary Myxococcus xanthus is a surface‐motile bacterium that has adapted at least one chemosensory system to allow directed movement towards the slowly diffusible lipid phosphatidylethanolamine (PE). The Dif chemosensory pathway is remarkable because it has at least three inputs coupled to outputs that control extracellular matrix (ECM) production and lipid chemotaxis. The methyl‐accepting chemotaxis protein, DifA, has two different sensor inputs that have been localized by mutagenesis. The Dif chemosensory pathway employs a novel protein that slows adaptation. Lipid chemotaxis may play important roles in the M. xanthus life cycle where prey‐specific and development‐specific attractants have been identified. Lipid chemotaxis may also be an important mechanism for locating nutrients by lung pathogens such as Pseudomonas aeruginosa.
Construction and analysis of chromosomal Clostridium difficile mutants
Authors: O'Connor Jennifer R. , Lyras Dena , Farrow Kylie A. , Adams Vicki , Powell David R. , Hinds Jason , Cheung Jackie K. , Rood Julian I. 
Published: August 2006

Summary Clostridium difficile is an emerging nosocomial pathogen of increasing importance and virulence but our ability to study the molecular mechanisms underlying the pathogenesis of C. difficile‐associated disease has been limited because of a lack of tools for its genetic manipulation. We have now developed a reproducible method for the targeted insertional inactivation of chromosomal C. difficile genes. The approach relies on the observation that an Escherichia coli–Clostridium perfringens shuttle vector is unstable in C. difficile and can be used as a form of conditional lethal vector to deliver gene constructs to the chromosome. We have used this methodology to insertionally inactivate two putative response regulator genes, rgaR and rgbR, which encode proteins with similarity to the toxin gene regulator, VirR, from C. perfringens. Transcriptomic analysis demonstrated that the C. difficile RgaR protein positively regulated four genes, including a putative agrBD operon. The RgaR protein was also purified and shown to bind specifically to sites that contained two consensus VirR boxes located just upstream of the putative promoters of these genes. The development of this methodology will significantly enhance our ability to use molecular approaches to develop a greater understanding of the ability of C. difficile to cause disease.
Mapped Ds/T‐DNA launch pads for functional genomics in barley
Authors: Zhao Tiehan , Palotta Margaret , Langridge Peter , Prasad Manoj , Graner Andreas , Schulze‐Lefert Paul , Koprek Thomas 
Published: August 2006

SummaryA system for targeted gene tagging and local saturation mutagenesis based on maize transposable elements (Ac/Ds) was developed in barley (Hordeum vulgare L.). We generated large numbers of transgenic barley lines carrying a single copy of the non‐autonomous maize Ds element at defined positions in the genome. Independent Ds lines were either generated by activating Ds elements in existing single‐copy lines after crossing with AcTPase‐expressing plants or by Agrobacterium‐mediated transformation. Genomic DNA flanking Ds and T‐DNA insertion sites from over 200 independent lines was isolated and sequenced, and was used for a sequence based mapping strategy in a barley reference population. More than 100 independent Ds insertion sites were mapped and can be used as launch pads for future targeted tagging of genes in the vicinity of the insertion sites. Sequence analysis of Ds and T‐DNA flanking regions revealed a sevenfold preference of both mutagens for insertion into non‐redundant, gene‐containing regions of the barley genome. However, whilst transposed Ds elements preferentially inserted adjacent to regions with a high number of predicted and experimentally validated matrix attachment regions (nuclear MARs), this was not the case for T‐DNA integration sites. These findings and an observed high transposition frequency from mapped launch pads demonstrate the future potential of gene tagging for functional genomics and gene discovery in barley.
Enhanced degradation in soil of tri‐allate and other carbamate pesticides following application of tri‐allate
Authors: COTTERILL E. G. , OWEN P. G. 
Published: August 2006

SummaryTri‐allate degraded faster in soil from a site (T1) that had received 1·7 kg ha−1 of tri‐allate annually for 23 years than in soil from an adjacent site (TO) that had received no pesticide application. Soil from the untreated site, which had been removed to a glasshouse and treated three times per annum with tri‐allate at 1·7 kg ha−1 for 7 years (T2), also showed faster degradation. Soil previously treated with tri‐allate showed an increased degradation rate for carbofuran and EPTC but not for aldicarb. A further experiment, 2 years after the last treatment with tri‐allate, showed that the enhanced degradation effect was still present. Degradation rates were always in the order T1 > T2 > T0 for tri‐allate, EPTC and carbofuran. Half‐life for degradation was reduced for tri‐allate and carbofuran by approximately 40% in the previously treated soils and for EPTC by approximately 80% when compared with the previously untreated soil.
Distinct features of chronic rhinosinusitis with and without nasal polyps
Authors: Polzehl D. , Moeller P. , Riechelmann H. , Perner S. 
Published: August 2006

Background:  Based on the presence of nasal polyps on endoscopy, chronic rhinosinusitis (CRS) may be clinically divided in CRS with nasal polyps and CRS without nasal polyps. It is unclear, whether CRS with nasal polyps and CRS without nasal polyps represent different disease entities or just different stages of one single disease. In case of one disease, only minor histopathological differences between CRS with small early‐stage polyps (CRSNP(+)) and CRS without nasal polyps (CRSNP−) were expected.Methods:  Patients with CRSNP(+) confined to the infundibular region or CRSNP− were selected. Histochemical and immunohistochemical characterization of ethmoidal mucosa was performed on formalin‐fixed and paraffin‐embedded tissue specimens. Frequency and distribution of eosinophils, neutrophils, mast cells, IgE+ cells, macrophages, B‐ and T‐cell subsets, natural killer cells, plasma cells and goblet cells were assessed. In addition, the thickness of the basal membrane was evaluated.Results:  Nine CRS patients without detectable polyps, and 11 patients with small early‐stage polyps confined to the infundibular region were selected. Despite adjacent polyp stage, the amount of round cell infiltration (P < 0.05), number of eosinophils (P < 0.05), and plasma cells (P < 0.01) significantly differed in the ethmoidal specimens from patients of the two groups.Conclusion:  Substantial histopathological differences were observed in ethmoidal mucosa of CRSNP(+) and CRSNP− patients. Thus, the results of this investigation support the concept that CRS with nasal polyps and CRS without nasal polyps are two different disease entities rather than different stages of one single disease, but may also be interpreted as a higher degree of inflammation.
Ectomycorrhizal colonization slows root decomposition: thepost‐mortemfungal legacy
Authors: Adam Langley J. , Chapman Samantha K. , Hungate Bruce A. 
Published: August 2006

AbstractThe amount of carbon plants allocate to mycorrhizal symbionts exceeds that emitted by human activity annually. Senescent ectomycorrhizal roots represent a large input of carbon into soils, but their fate remains unknown. Here, we present the surprising result that, despite much higher nitrogen concentrations, roots colonized by ectomycorrhizal (EM) fungi lost only one‐third as much carbon as non‐mycorrhizal roots after 2 years of decomposition in a piñon pine (Pinus edulis) woodland. Experimentally excluding live mycorrhizal hyphae from litter, we found that live mycorrhizal hyphae may alter nitrogen dynamics, but the afterlife (litter‐mediated) effects of EM fungi outweigh the influences of live fungi on root decomposition. Our findings indicate that a shift in plant allocation to mycorrhizal fungi could promote carbon accumulation in soil by this pathway. Furthermore, EM litters could directly contribute to the process of stable soil organic matter formation, a mechanism that has eluded soil scientists.