bluuebunny/crossref_metadata_2025 huggingface dataset:
Circumgranular bassanite in a gypsum crust from eastern Algeria – a potential palaeosurface indicator
Authors: Mees Florias , Stoops Georges
Published: December 2004

Detrital sand grains are surrounded by thin bassanite coatings in the upper part of a coarse‐crystalline gypsum crust from the Algerian Sahara. The bassanite developed by topotactic replacement of the surrounding gypsum in the absence of a liquid phase. Heating experiments using a gypsum crystal with sand inclusions produced similar patterns and textures. In one experiment, bassanite developed around quartz and carbonate grains but not along the sides of the heated gypsum crystal. This is the result of differences in heat capacity between gypsum, quartz and calcite. Bassanite formation in the crust from Algeria was not controlled by differences in thermal properties. Instead, the bassanite apparently formed under conditions of thermal equilibrium. The occurrence of bassanite as circumgranular coatings in the crust is interpreted as being related to the availability of submicroscopic space along the contact between the gypsum cement and the enclosed sand grains. The presence of coatings of this type, or derived relict features, is a potential criterion for the recognition of palaeosurfaces.
Effects of temperature and humidity upon the transport of sedimentary particles by wind
Authors: Neuman Cheryl McKenna
Published: December 2004

Wind tunnel simulations of aeolian transport carried out over a range in mean temperature between 32 °C and −9 °C suggest that cold airflows support higher mass transport rates (Q) than very warm air. The magnitude of this increase is larger than expected, so that analytical and semi‐empirical models underestimate Q. Extrapolation of the results suggests that, at −40 °C, as for example in the dry valleys of Antarctica in winter, Q may be as much as 70% higher than for the equivalent wind speed in hot deserts at air temperatures of 40 °C. Temperature‐dependent changes in air density and turbulence contribute to this result. The decreased tension of water adsorbed onto particle surfaces at low temperatures is postulated to reduce interparticle cohesion and, thus, to increase the elasticity of particle impacts on cold beds. Definition of the roles that temperature and humidity play in aeolian transport is relevant to studies of palaeoenvironmental reconstruction and extraterrestrial (or planetary) geology. Investigation of present‐day, cold climate features and of climate change effects also requires knowledge of these fundamental relations.
Comparison of particle size characteristics of the Tertiary ‘red clay’ and Pleistocene loess in the Chinese Loess Plateau: implications for origin and sources of the ‘red clay’
Authors: Yang S. L. , Ding Z. L.
Published: December 2004

The origin of the Tertiary ‘red clay’ underlying the Pleistocene loess in the Chinese Loess Plateau remains controversial, although several lines of evidence have suggested a wind‐blown origin. This study examines the particle‐size parameters of the late Miocene and Pliocene ‘red clay’ by comparing it with those of the late Pleistocene loess. The particle‐size distribution of a total of 15 339 loess and 6394 ‘red clay’ samples taken from 12 loess sections along a north–south transect and two ‘red clay’ sequences at Lingtai and Jingchuan was systematically analysed. The median grain size, skewness and kurtosis of the late Pleistocene loess all show a systematic southward change and are principally influenced by distance from source region. The spatial and temporal differentiation of dust deposits is expressed in a skewness–kurtosis–median grain size ternary diagram, from which the distance to the source region can be inferred. The particle‐size characteristics of the Tertiary ‘red clay’ sediments are very similar to those of the palaeosols within the late Pleistocene loess deposits, suggesting an aeolian origin for the ‘red clay’. Based on the comparison of ‘red clay’ and loess in the ternary diagrams, it is inferred that the source–sink distance was greater in the Neogene than in the last and penultimate interglacials, and that the dust source region in north‐western China underwent a progressive expansion during the period from at least 7·0 Ma to the present.
Diagenetic overprinting of the sphaerosiderite palaeoclimate proxy: are records of pedogenic groundwater δ18O values preserved?
Authors: Ufnar David F. , González Luis A. , Ludvigson Greg A. , Brenner Robert L. , Witzke Brian J.
Published: December 2004

Meteoric sphaerosiderite lines (MSLs), defined by invariant δ18O and variable δ13C values, are obtained from ancient wetland palaeosol sphaerosiderites (millimetre‐scale FeCO3 nodules), and are a stable isotope proxy record of terrestrial meteoric isotopic compositions. The palaeoclimatic utility of sphaerosiderite has been well tested; however, diagenetically altered horizons that do not yield simple MSLs have been encountered. Well‐preserved sphaerosiderites typically exhibit smooth exteriors, spherulitic crystalline microstructures and relatively pure (> 95 mol% FeCO3) compositions. Diagenetically altered sphaerosiderites typically exhibit corroded margins, replacement textures and increased crystal lattice substitution of Ca2+, Mg2+ and Mn2+ for Fe2+. Examples of diagenetically altered Cretaceous sphaerosiderite‐bearing palaeosols from the Dakota Formation (Kansas), the Swan River Formation (Saskatchewan) and the Success S2 Formation (Saskatchewan) were examined in this study to determine the extent to which original, early diagenetic δ18O and δ13C values are preserved. All three units contain poikilotopic calcite cements with significantly different δ18O and δ13C values from the co‐occurring sphaerosiderites. The complete isolation of all carbonate phases is necessary to ensure that inadvertent physical mixing does not affect the isotopic analyses. The Dakota and Swan River samples ultimately yield distinct MSLs for the sphaerosiderites, and MCLs (meteoric calcite lines) for the calcite cements. The Success S2 sample yields a covariant δ18O vs. δ13C trend resulting from precipitation in pore fluids that were mixtures between meteoric and modified marine phreatic waters. The calcite cements in the Success S2 Formation yield meteoric δ18O and δ13C values. A stable isotope mass balance model was used to produce hyperbolic fluid mixing trends between meteoric and modified marine end‐member compositions. Modelled hyperbolic fluid mixing curves for the Success S2 Formation suggest precipitation from fluids that were < 25% sea water.
Tepee‐shaped agglutinated microbialites: an example from a Famennian carbonate platform on the Lennard Shelf, northern Canning Basin, Western Australia
Authors: Chow Nancy , George Annette D.
Published: December 2004

Distinctive, metre‐scale antiformal structures are well developed in a Famennian carbonate platform in the Chedda Cliffs area of the Lennard Shelf reef complexes. The structures are distinguished by chevron‐shaped crests and thickened cores and contain abundant non‐skeletal allochems (ooids/pisoids, peloids and intraclasts) of silt to pebble size and variably developed laminations and fenestrae. The internal morphology and pervasive occurrence of fenestral clotted and wavy laminated fabrics suggest that these structures are microbial mounds composed of agglutinated stromatolites and thrombolites. Microbial fabrics most probably originated through sediment trapping and binding by microbial mats with early lithification involving microbial calcification and cementation of trapped sediment. The facies and stratigraphic context of the mounds support a shallow subtidal, transitional backreef to reef‐flat setting; however, alone these mounds do not provide unequivocal environmental information. Other large antiformal structures in Famennian platforms on the Lennard Shelf, previously described as tepee structures, show morphological similarities to the Chedda Cliffs mounds, which suggests that these other structures may also be microbial mounds. The presence of microbial mounds in platform successions further highlights the importance of microbial communities in the Lennard Shelf reef complexes.
Three‐dimensional modelling of an isolated carbonate buildup (Triassic, Dolomites, Italy)
Authors: Blendinger Wolfgang , Brack Peter , Norborg Arne Kristoffer , Wulff‐Pedersen Erik
Published: December 2004

The Middle Triassic carbonate buildups of the Dolomites show facies similarities with mud mounds but display apparent architectural elements of flat‐topped carbonate platforms. In order to test whether the facies similarities to mounds are also reflected in the internal buildup architecture, a three‐dimensional modelling study of the Middle Triassic Monte Cernera buildup has been carried out. The Cernera buildup exhibits apparent geometries suggesting a mounded platform in the lower and uppermost part of the buildup, separated by an interval with apparent platform geometry and a retrogradational platform interior, which is difficult to explain with a flat top platform model. For this purpose, a number of three‐dimensional models were constructed using the three‐dimensional modelling programme petrelTM. Key geological horizons were constructed based on outcrop measurements, intermediate horizons were calculated in the modelling program, and the intersections of the modelled layers with a digital topography surface were displayed and compared with outcrop photographs. The models were refined stepwise until a best fit with the actual bedding architecture was achieved. The best fit model shows that the mounded geometries in the lower and uppermost part of the buildup are real architectural elements. The intermediate platform stage, about 1·5 km across, had probably retained a mounded top with a relief of up to 50 m, which is difficult to distinguish from an absolutely flat top, but necessary to explain the retrogradational platform interior. The present study shows that Monte Cernera was dominated by mounded geometries at all stages of platform development. The mounded geometry plus facies data suggest that the platform is a deep‐water accumulation, below the zone of intense wave energy, but within the photic zone. The Cernera represents a tropical buildup type, which did not have the capacity to grow into continuously wave‐swept environments because of the small size and the absence of a wave‐resistant energy barrier. Such buildup types are probably common after major crises in earth history, when reef organisms were virtually absent.
Tropical westerlies over Pangaean sand seas
Authors: Loope David B. , Steiner Maureen B. , Rowe Clinton M. , Lancaster Nicholas
Published: December 2004

Cross‐equatorial, westerly winds are key features of tropical circulation in monsoonal regions. Although prominent in numerical climate models of Pangaea (the supercontinent straddling earth's equator, Late Palaeozoic to Early Mesozoic), such flow has not been confirmed previously by migration directions of ancient dunes. Wind‐blown sandstones that span 100 million years of earth history are widely exposed in south‐western USA. If recent palaeomagnetic data from the Colorado Plateau are used to correct Mesozoic palaeogeographic maps, the Plateau is placed about 10° further south than previously assumed, and the prevailing north‐westerly surface winds recorded by dune‐deposited sandstones are explicable as cross‐equatorial westerlies – the hallmark of modern monsoon circulation. Permian to Early Jurassic dunes were driven by north‐westerlies produced by a steep pressure gradient spanning the supercontinent during December–January–February. Although winds are light in most modern, near‐equatorial settings, the East African Jet accounts for more than half the cross‐equatorial flow in June–July–August. The thicknesses of annual depositional cycles within the Navajo Sandstone indicate that the near‐equatorial, north‐westerly winds that drove these particular dunes were stronger than the modern East African Jet. The Early Jurassic dunes that deposited the thick cycles were positioned west of the dominant (southern hemisphere) thermal low and against highlands to the west – a setting very similar to the East African Jet. The mountains along the western coast of Pangaea not only enhanced wind strength, but also cast a rain shadow that allowed active dunes to extend very close to the palaeoequator.
A revision of the Encarsia longifasciata species group (Hymenoptera: Aphelinidae)
Authors: Pedata Paolo A. , Polaszek Andrew
Published: December 2004

Abstract.  The Encarsia longifasciata group is established and revised, and its relationship to other species groups of Encarsia is discussed with reference to biological, morphological and molecular evidence. Principal component analysis on all available specimens provided supporting evidence for the existence of five species, two of which are described herein as new: E. dewa Pedata & Polaszek, sp.n and E. prinslooi Pedata & Polaszek, sp.n. All species are either diagnosed or described, and illustrated, and information is given on their distribution and host range. Additional information on the biology and larval stages, and scanning electron micrographs of morphological details, are provided for E. arabica Hayat. A preliminary phylogenetic study using 28S D2 rDNA sequence data for E. arabica was inconclusive, but suggested possible affinities between the longifasciata and parvella species groups. An illustrated dichotomous key to all species of the E. longifasciata group is given.
Systematics and cladistic analysis of Cerophytidae (Elateroidea: Coleoptera)
Authors: Costa Cleide , Vanin Sergio A. , Lawrence John F. , Ide Sergio
Published: December 2004

Abstract. The elateroid family Cerophytidae, originally based onCerophytumLatreille, is characterized and revised. Detailed morphological studies of adults and a cladistic analysis permitted the recognition of three well‐defined lineages: one in the Holarctic Region, and the other two in the Neotropical Region, each one distributed from southern Mexico to South America. The resulting cladogram for these genera is ((Cerophytum) (Brachycerophytum,Phytocerum)).Cerophytumincludes four species:C. elateroides(Latreille) (type species, southern and central Europe),C. convexicolle(LeConte) (western U.S.A.),C. japonicumSasaji (Japan) andC. pulsator(Haldeman) (eastern U.S.A.).Brachycerophytumgen.n. contains two Neotropical species:B. fuscicorne(Bonvouloir) comb.n. (type species, Mexico to Colombia) andB. sinchonasp.n. (Peru and Bolivia).Phytocerumgen.n. includes fifteen species:P. golbachisp.n. (type species, Argentina),P. allenisp.n. (Costa Rica, Nicaragua),P. belloisp.n. (Brazil),P. biraisp.n. (Brazil),P. boliviense(Golbach) comb.n. (Bolivia),P. burakowskiisp.n. (Trinidad),P. cayennense(Bonvouloir) comb.n. (Mexico, French Guyana, Brazil),P. distinguendum(Soares & Peracchi) comb.n. (Brazil, Paraguay and Argentina),P. serraticornesp.n. (Guatemala),P.golbachisp.n. (Argentina),P. ingenssp.n. (Brazil),P. inpasp.n. (Brazil),P. minutum(Golbach) comb.n. (Argentina),P. simonkaisp.n. (Trinidad),P. trinidadense(Golbach) comb.n. (Trinidad) andP. zikani(Soares & Peracchi) comb.n. (Brazil). Diagnoses for the genera, redescriptions and descriptions for the species, as well as keys to genera and species, are provided. The larva ofC. elateroidesis redescribed.
Methylation of histone H3 in euchromatin of plant chromosomes depends on basic nuclear DNA content
Authors: Houben Andreas , Demidov Dmitri , Gernand Dorota , Meister Armin , Leach Carolyn R. , Schubert Ingo
Published: December 2004

Strong methylation of lysine 4 (K4) and low methylation of lysine 9 (K9) have been proposed as modifications of histone H3, typical for transcriptionally active euchromatin and the opposite for inactive heterochromatin. We have analysed the correlation between the global distribution of histone H3, methylated at either lysine 4 or lysine 9, and of microscopically detectable euchromatic or heterochromatic regions in relation to genome size for 24 plant species. Two different distribution patterns of methylated (K9)H3 (Met(K9)H3) were found that depend on genome size. For most species with small genomes (1C <500 Mbp), including Arabidopsis thaliana, strong methylation of (K9)H3 was restricted to constitutive heterochromatin. Species with larger genomes showed a uniform distribution of Met(K9)H3. Contrary to this and regardless of the genome size, methylated (K4)H3 (Met(K4)H3) was found to be enriched within the euchromatin of all species. Transcriptionally less active B chromosomes showed the same patterns as basic A chromosomes. We thus propose that large genomes with high amounts of dispersed repetitive sequences (mainly retroelements) have to silence these sequences and therefore display epigenetic modifications such as methylation of DNA and (K9)H3 also within euchromatic regions.
Antisense inhibition of NADH glutamate synthase impairs carbon/nitrogen assimilation in nodules of alfalfa (Medicago sativa L.)
Authors: Cordoba Elizabeth , Shishkova Svetlana , Vance Carroll P. , Hernández Georgina
Published: December 2004

Legumes acquire significant amounts of nitrogen for growth from symbiotic nitrogen fixation. The glutamine synthetase (GS)/NADH‐dependent glutamate synthase (NADH‐GOGAT) cycle catalyzes initial nitrogen assimilation. This report describes the impact of specifically reducing nodule NADH‐GOGAT activity on symbiotic performance of alfalfa (Medicago sativa L.). Four independent transgenic alfalfa lines, designated GA89, GA87, GA88, and GA82 (for GOGATantisense), containing an antisense NADH‐GOGAT cDNA fragment under the control of the soybean leghemoglobin (lbc3) promoter were evaluated. The GA plants were fertile and showed normal growth in non‐symbiotic conditions. The NADH‐GOGAT antisense transgene was heritable and the T1 plants showed phenotypic alterations – similar to primary transformants. Clonally propagated plants were inoculated with Sinorhizobium meliloti after rooting and the symbiotic phenotype was analyzed 21 days post‐inoculation. Nodules of each GA line had reduced NADH‐GOGAT activity, ranging from 33 to 87% of control plants, that was accompanied by comparable decreases in RNA and protein. Plants from the GA89 line, with the lowest NADH‐GOGAT activity (c. 30%), presented a strikingly altered symbiotic phenotype: concomitantly activities of key enzyme for carbon and nitrogen assimilation decreased; nodule amino acids and amides were reduced while sucrose accumulated. Antisense GOGAT plants were chlorotic, reduced in fresh weight, and had a lower N content than control plants. Photosynthesis was also impaired in antisense plants. Specifically, reducing NADH‐GOGAT in nodules resulted in plants having impaired nitrogen assimilation and altered carbon/nitrogen metabolic flux.
A novel protein from Brassica napus has a putative KID domain and responds to low temperature
Authors: Gao Ming‐Jun , Schäfer Ulrike A. , Parkin Isobel A. P. , Hegedus Dwayne D. , Lydiate Derek J. , Hannoufa Abdelali
Published: December 2004

To identify factors that interact with histone deacetylase (HDAC) in Brassica napus, a yeast two‐hybrid library was screened using the Arabidopsis HDA19 as bait. A novel protein, bnKCP1, containing a putative kinase‐inducible domain (KID) was found to interact with HDA19. Southern blot analysis indicated that the bnKCP1 gene belongs to a small gene family of at least three members. Northern blot analysis showed bnKCP1 to be strongly expressed in stems, flowers, roots, and immature siliques, but not in leaf blades of seedlings. The accumulation of bnKCP1 transcript in the leaf blades was induced significantly within 4 h of exposure of B. napus seedlings to cold stress, whereas treatment of leaf blades with inomycin, an ionophore of Ca2+, caused a rapid (30 min) but transient induction of bnKCP1 expression. In contrast to that observed in leaf blades, expression of bnKCP1 in the stems was repressed upon cold treatment. In vitro and in vivo protein‐binding assays showed that bnKCP1 interacts with HDA19 via the KID domain, and that S188 is critical for bnKCP1–HDA19 interaction. BnKCP1 also exerted modest transactivation of the lacZ reporter gene in yeast through its N‐terminal region. These assays suggest that bnKCP1 may function as a transcription factor, which regulates gene expression through interaction with HDA19.
Enhancement of growth by expression of poplar cellulase in Arabidopsis thaliana
Authors: Park Yong Woo , Tominaga Rumi , Sugiyama Junji , Furuta Yuzo , Tanimoto Eiichi , Samejima Masahiro , Sakai Fukumi , Hayashi Takahisa
Published: December 2004

To study the role of cellulose and cellulase in plant growth, we expressed poplar cellulase (PaPopCel1) constitutively in Arabidopsis thaliana. Expression increased the size of the rosettes due to increased cell size. The change in growth was accompanied by changes in biomechanical properties due to cell wall structure indicative of decrease in xyloglucan cross‐linked with cellulose microfibrils by chemical analysis and nuclear magnetic resonance (NMR) spectra. The result supports the concept that the paracrystalline sites of cellulose microfibrils are attacked by poplar cellulase to loosen xyloglucan intercalation and this irreversible wall modification promotes the enlargement of plant cells.
The redistribution of protein sulfur in transgenic rice expressing a gene for a foreign, sulfur‐rich protein
Authors: Hagan N. D. , Upadhyaya N. , Tabe L. M. , Higgins T. J. V.
Published: December 2004

Sulfur amino acid composition is an important determinant of seed protein quality. A chimeric gene encoding sunflower seed albumin (SSA), one of the most sulfur‐rich seed storage proteins identified so far, was introduced into rice (Oryza sativa) in order to modify cysteine and methionine content of the seed. Analysis of a transgenic line expressing SSA at approximately 7% of total seed protein revealed that the mature grain showed little change in the total sulfur amino acid content compared to the parental genotype. This result indicated that the transgenic rice grain was unable to respond to the added demand for cysteine and methionine imposed by the production of SSA. Analysis of the protein composition of the transgenic grain showed changes in the relative levels of the major seed storage proteins, as well as some non‐storage proteins, compared to non‐transgenic controls. Changes observed at the protein level were concomitant with differences in mRNA accumulation but not always with the level of transcription. The limited sulfur reserves appeared to be re‐allocated from endogenous proteins to the new sulfur sink in the transgenic grain. We hypothesize that this response is mediated by a signal transduction pathway that normally modulates seed storage protein composition in response to environmental fluctuations in sulfur availability, via both transcriptional and post‐transcriptional control of gene expression.
Efficient transposition of the Tnt1 tobacco retrotransposon in the model legume Medicago truncatula
Authors: D'Erfurth Isabelle , Cosson Viviane , Eschstruth Alexis , Lucas Helene , Kondorosi Adam , Ratet P.
Published: December 2004

The tobacco element, Tnt1, is one of the few active retrotransposons in plants. Its transposition is activated during protoplast culture in tobacco and tissue culture in the heterologous host Arabidopsis thaliana. Here, we report its transposition in the R108 line of Medicago truncatula during the early steps of the in vitro transformation–regeneration process. Two hundred and twenty‐five primary transformants containing Tnt1 were obtained. Among them, 11.2% contained only transposed copies of the element, indicating that Tnt1 transposed very early and efficiently during the in vitro transformation process, possibly even before the T‐DNA integration. The average number of insertions per transgenic line was estimated to be about 15. These insertions were stable in the progeny and could be separated by segregation. Inspection of the sequences flanking the insertion sites revealed that Tnt1 had no insertion site specificity and often inserted in genes (one out of three insertions). Thus, our work demonstrates the functioning of an efficient transposable element in leguminous plants. These results indicate that Tnt1 can be used as a powerful tool for insertion mutagenesis in M. truncatula.
A novel C‐terminal proteolytic processing of cytosolic pyruvate kinase, its phosphorylation and degradation by the proteasome in developing soybean seeds
Authors: Tang Guo‐Qing , Hardin Shane C. , Dewey Ralph , Huber Steven C.
Published: December 2004

Cytosolic pyruvate kinase (ATP:pyruvate 2‐O‐phosphotransferase, EC 2.7.1.40) is an important glycolytic enzyme, but the post‐translational regulation of this enzyme is poorly understood. Sequence analysis of the soybean seed enzyme suggested the potential for two phosphorylation sites: site‐1 (FVRKGS220DLVN) and site‐2 (VLTRGGS407TAKL). Sequence‐ and phosphorylation state‐specific antipeptide antibodies established that cytosolic pyruvate kinase (PyrKinc) is phosphorylated at both sites in vivo. However, by SDS–PAGE, the phosphorylated polypeptides were found to be smaller (20–51 kDa) than the full length (55 kDa). Biochemical separations of seed proteins by size exclusion chromatography and sucrose‐density gradient centrifugation revealed that the phosphorylated polypeptides were associated with 26S proteasomes. The 26S proteasome particle in developing seeds was determined to be of approximately 1900 kDa. In vitro, the 26S proteasome degraded associated PyrKinc polypeptides, and this was blocked by proteasome‐specific inhibitors such as MG132 and NLVS. By immunoprecipitation, we found that some part of the phosphorylated PyrKinc was conjugated to ubiquitin and shifted to high molecular mass forms in vivo. Moreover, recombinant wild‐type PyrKinc was ubiquitinated in vitro to a much greater extent than the S220A and S407A mutant proteins, suggesting a link between phosphorylation and ubiquitination. In addition, during seed development, a progressive accumulation of a C‐terminally truncated polypeptide of approximately 51 kDa was observed that was in parallel with a loss of the full‐length 55 kDa polypeptide. Interestingly, the C‐terminal 51 kDa truncation showed not only pyruvate kinase activity but also activation by aspartate. Collectively, the results suggest that there are two pathways for PyrKinc modification at the post‐translational level. One involves partial C‐terminal truncation to generate a 51 kDa pyruvate kinase subunit which might have altered regulatory properties and the other involves phosphorylation and ubiquitin conjugation that targets the protein to the 26S proteasome for complete degradation.
Barley sex6 mutants lack starch synthase IIa activity and contain a starch with novel properties
Authors: Morell Matthew K. , Kosar‐Hashemi Behjat , Cmiel Mark , Samuel Michael S. , Chandler Peter , Rahman Sadequr , Buleon Alain , Batey Ian L. , Li Zhongyi
Published: December 2004

Analysis of barley shrunken grain mutants has identified lines with a novel high amylose starch phenotype. The causal mutation is located at the sex6 locus on chromosome 7H, suggesting the starch synthase IIa (ssIIa) gene as a candidate gene altered by the mutation. Consistent with this hypothesis, no evidence of SSIIa protein expression in either the starch granule or soluble fractions of the endosperm was found. Sequences of the starch synthase IIa gene, ssIIa, from three independent sex6 lines showed the presence of a stop codon preventing translation of the ssIIa transcript in each line. Perfect segregation of the starch phenotype with the presence of stop codons in the ssIIa gene was obtained, providing strong evidence for the lesion in the ssIIa gene being the causal mutation for the sex6 phenotype. The loss of SSIIa activity in barley leads to novel and informative phenotypes. First, a decrease in amylopectin synthesis to less than 20% of the wild‐type levels indicates that SSIIa accounts for the majority of the amylopectin polymer elongation activity in barley. Secondly, in contrast to high amylose starches resulting from branching enzyme downregulation, the sex6 starches have a shortened amylopectin chain length distribution and a reduced gelatinisation temperature. Thirdly, the mutation leads to pleiotropic effects on other enzymes of the starch biosynthesis pathway, abolishing the binding of SSI, branching enzyme IIa and branching enzyme IIb to the starch granules of sex6 mutants, while not significantly altering their expression levels in the soluble fraction.
Topology of the network integrating salicylate and jasmonate signal transduction derived from global expression phenotyping
Authors: Glazebrook Jane , Chen Wenqiong , Estes Bram , Chang Hur‐Song , Nawrath Christiane , Métraux Jean‐Pierre , Zhu Tong , Katagiri Fumiaki
Published: December 2004

The signal transduction network controlling plant responses to pathogens includes pathways requiring the signal molecules salicylic acid (SA), jasmonic acid (JA), and ethylene (ET). The network topology was explored using global expression phenotyping of wild‐type and signaling‐defective mutant plants, including eds3, eds4, eds5, eds8, pad1, pad2, pad4, NahG, npr1, sid2, ein2, and coi1. Hierarchical clustering was used to define groups of mutations with similar effects on gene expression and groups of similarly regulated genes. Mutations affecting SA signaling formed two groups: one comprised of eds4, eds5, sid2, and npr1‐3 affecting only SA signaling; and the other comprised of pad2, eds3, npr1‐1, pad4, and NahG affecting SA signaling as well as another unknown process. Major differences between the expression patterns in NahG and the SA biosynthetic mutant sid2 suggest that NahG has pleiotropic effects beyond elimination of SA. A third group of mutants comprised of eds8, pad1, ein2, and coi1 affected ethylene and jasmonate signaling. Expression patterns of some genes revealed mutual inhibition between SA‐ and JA‐dependent signaling, while other genes required JA and ET signaling as well as the unknown signaling process for full expression. Global expression phenotype similarities among mutants suggested, and experiments confirmed, that EDS3 affects SA signaling while EDS8 and PAD1 affect JA signaling. This work allowed modeling of network topology, definition of co‐regulated genes, and placement of previously uncharacterized regulatory genes in the network.
ER quality control can lead to retrograde transport from the ER lumen to the cytosol and the nucleoplasm in plants
Authors: Brandizzi Federica , Hanton Sally , DaSilva Luis L. Pinto , Boevink Petra , Evans David , Oparka Karl , Denecke Jürgen , Hawes Chris
Published: December 2004

Quality control in the secretory pathway is a fundamental step in preventing deleterious effects that may arise by the release of malfolded proteins into the cell or apoplast. Our aims were to visualise and analyse the disposal route followed by aberrant proteins within a plant cell in vivo using fluorescent protein technology. A green fluorescent protein (GFP) fusion was detected in the cytosol and the nucleoplasm in spite of the presence of an N‐terminal secretory signal peptide. In contrast to secreted GFP, the fusion protein was retained in the cells where it was degraded slowly, albeit at a rate much higher than that of the endoplasmic reticulum (ER)‐retained derivative GFP‐HDEL. The fusion protein could not be stabilised by inhibitors of transport or the cytosolic proteasome. However, the protein is a strong lumenal binding protein (BiP) ligand. Complete signal peptide processing even after long‐term expression in virus‐infected leaves rules out the possibility that the documented accumulation in the cytosol and nucleoplasm is because of the bypassing of the translocation pores. The data are consistent with the hypothesis that the fusion protein is disposed off from the ER via a retrograde translocation back to the cytosol. Moreover, accumulation in the nucleoplasm was shown to be microtubule dependent unlike the well‐documented diffusion of cytosolically expressed GFP into the nucleoplasm. The apparent active transport of the GFP fusion into the nucleoplasm may indicate an as yet undiscovered feature of the ER‐associated degradation (ERAD) pathway and explain the insensitivity to degradation by proteasome inhibitors.
Cyclopentenone isoprostanes induced by reactive oxygen species trigger defense gene activation and phytoalexin accumulation in plants
Authors: Thoma Ingeborg , Loeffler Christiane , Sinha Alok K. , Gupta Meetu , Krischke Markus , Steffan Bert , Roitsch Thomas , Mueller Martin J.
Published: December 2004

Lipid peroxidation may be initiated either by lipoxygenases or by reactive oxygen species (ROS). Enzymatic oxidation of α‐linolenate can result in the biosynthesis of cyclic oxylipins of the jasmonate type while free‐radical‐catalyzed oxidation of α‐linolenate may yield several classes of cyclic oxylipins termed phytoprostanes in vivo. Previously, we have shown that one of these classes, the E1‐phytoprostanes (PPE1), occurs ubiquitously in plants. In this work, it is shown that PPE1 are converted to novel cyclopentenone A1‐ and B1‐phytoprostanes (PPA1 and PPB1) in planta. Enhanced formation of PPE1, PPA1, and PPB1 is observed after peroxide stress in tobacco cell cultures as well as after infection of tomato plants with a necrotrophic fungus, Botrytis cinerea. PPA1 and PPB1 display powerful biologic activities including activation of mitogen‐activated protein kinase (MAPK) and induction of glutathione‐S‐transferase (GST), defense genes, and phytoalexins. Data collected so far infer that enhanced phytoprostane formation is a general consequence of oxidative stress in plants. We propose that phytoprostanes are components of an oxidant‐injury‐sensing, archaic signaling system that serves to induce several plant defense mechanisms.
ydk1‐D, an auxin‐responsive GH3 mutant that is involved in hypocotyl and root elongation
Authors: Takase Tomoyuki , Nakazawa Miki , Ishikawa Akie , Kawashima Mika , Ichikawa Takanari , Takahashi Naoki , Shimada Hiroaki , Manabe Katsushi , Matsui Minami
Published: December 2004

To study the GH3 gene family of Arabidopsis, we investigated a flanking sequence database of Arabidopsis activation‐tagged lines. We found a dwarf mutant, named yadokari 1‐D (ydk1‐D), that had a T‐DNA insertion proximal to a GH3 gene. ydk1‐D is dominant and has a short hypocotyl not only in light but also in darkness. Moreover, ydk1‐D has a short primary root, a reduced lateral root number, and reduced apical dominance. A GH3 gene, named YDK1, was upregulated in ydk1‐D, and YDK1 transgenic plants showed the ydk1‐D phenotype. YDK1 gene expression was induced by exogenously applied auxin and regulated by auxin‐response factor (ARF)7. In addition, YDK1 gene expression was downregulated by blue and far‐red (FR) lights. Strong promoter activity of YDK1 was observed in roots and flowers. These results suggest that YDK1 may function as a negative component in auxin signaling by regulating auxin activity.
Chromosome termini of the monocot plant Othocallis siberica are maintained by telomerase, which specifically synthesises vertebrate‐type telomere sequences
Authors: Weiss‐Schneeweiss Hanna , Riha Karel , Jang Chang Gee , Puizina Jasna , Scherthan Harry , Schweizer Dieter
Published: December 2004

Lack of Arabidopsis‐type T3AG3 telomere sequences has recently been reported for the majority of investigated taxa of the monocot order Asparagales. In order to investigate this phenomenon in more detail, we conducted extensive cytogenetic and molecular analyses of the telomeres in Othocallis siberica, a member of this order. Terminal restriction fragment analysis together with Bal31 exonuclease assay showed that chromosome termini in O. siberica are formed by long stretches (more than 10 kbp) of vertebrate‐type T2AG3 repeats. In addition, telomerase activity specifically synthesising (T2AG3)n sequence was detected in O. siberica protein extracts by telomerase repeat amplification protocol (TRAP). Fluorescence in situ hybridisation (FISH) revealed the presence of the vertebrate‐type T2AG3 telomere sequences at all chromosome termini and at a few additional regions of O. siberica chromosomes, whereas Arabidopsis‐type T3AG3 DNA and peptide nucleic acid (PNA) probes did not hybridise to chromosomes of Othocallis, except for polymorphic blocks in chromosomes 2 (interstitial) and 4 (terminal). These interstitial/terminal regions are apparently composed of large blocks of (T2AG3)n and (T3AG3)n DNA and represent a unique example of interspersion of two types of telomeric repeats within one genome. This may be a reflection of the recent evolutionary switch from Arabidopsis‐ to vertebrate‐type telomeric repeats in this plant group.
Cryopreservation of transformed and wild‐type Arabidopsis and tobacco cell suspension cultures
Authors: Menges Margit , Murray James A. H.
Published: December 2004

We have recently described Arabidopsis cell suspension cultures that can be effectively synchronised. Here, we describe procedures that allow clonal‐transformed cell suspension lines to be produced using Agrobacterium‐mediated transformation, and an optimised and straightforward procedure for the cryopreservation and recovery of both parental and transformed lines. Frozen cultures show 90% viability and rapid re‐growth after recovery. We show that the cryopreservation procedure is equally applicable to the frequently used tobacco bright yellow (BY)2 cell suspension culture, and that cell cycle synchronisation capacity of parental lines is maintained after both transformation and recovery from cryopreservation. The techniques require no specialised equipment, and are suitable for routine laboratory use, greatly facilitating the handling and maintenance of cell cultures and providing security against both contamination and cumulative somaclonal variation. Finally, the ability to store easily large numbers of transformed lines opens the possibility of using Arabidopsis cell suspension cultures for high‐throughput analysis.
Conservation of class C function of floral organ development during 300 million years of evolution from gymnosperms to angiosperms
Authors: Zhang Pingyu , Tan Hugh T. W. , Pwee Keng‐Hock , Kumar Prakash P.
Published: December 2004

Flower development in angiosperms is regulated by the family of MADS‐box transcription factors. MADS‐box genes have also been reported from gymnosperms, another major group of seed plants. AGAMOUS (AG) is the class C MADS‐box floral organ identity gene controlling the stamen and carpel development in Arabidopsis. We report the characterization of an ortholog of the AG gene, named Cycas AGAMOUS (CyAG), from the primitive gymnosperm Cycas edentata. The expression pattern of CyAG in Cycas parallels that of AG in Arabidopsis. Additionally, the gene structure, including the number and location of the introns, is conserved in CyAG and other AG orthologs known. Most importantly, functional analysis shows that CyAG driven by the AG promoter can rescue the loss‐of‐function ag mutant of Arabidopsis. However, the ectopic expression of CyAG in ag mutant Arabidopsis cannot produce the carpeloid and stamenoid organs in the first and second whorls, although the stamen and carpel are rescued in the third and fourth whorls of the transformants. These observations show that the molecular mechanism of class C function controlling reproductive organ identity (stamen and carpel of angiosperms or microsporophyll and megasporophyll of gymnosperms) arose before the divergence of angiosperms and gymnosperms, and has been conserved during 300 million years of evolution thereafter.
Three years of haemovigilance in a general university hospital
Authors: Michlig C. , Vu D.‐H. , Wasserfallen J.‐B. , Spahn D. R. , Schneider P. , Tissot J.‐D.
Published: December 2004

summary.The aim of this study is to describe a newly implemented haemovigilance system in a general university hospital. We present a series of short cases, highlighting particular aspects of the reports, and an overview of all reported incidents between 1999 and 2001. Incidents related to transfusion of blood products were reported by the clinicians using a standard preformatted form, giving a synopsis of the incident. After analysis, we distinguished, on the one hand, transfusion reactions, that are transfusions which engendered signs or symptoms, and, on the other hand, the incidents where management errors and/or dysfunctions took place. Over 3 years, 233 incidents were reported, corresponding to 4·2 events for 1000 blood products delivered. Of the 233, 198 (85%) were acute transfusion reactions and 35 (15%) were management errors and/or dysfunctions. Platelet units gave rise to statistically (P < 0·001) more transfusion reactions (10·7‰) than red blood cells (3·5‰) and fresh frozen plasma (0·8‰), particularly febrile nonhaemolytic transfusion reactions and allergic reactions. A detailed analysis of some of the transfusion incident reports revealed complex deviations and/or failures of the procedures in place in the hospital, allowing the implementation of corrective and preventive measures. Thus, the haemovigilance system in place in the ‘Centre Hospitalier Universitaire Vaudois, CHUV’ appears to constitute an excellent instrument for monitoring the security of blood transfusion.
Establishment of human heterohybridoma and lymphoblastoid cell lines specific for the Rh D and C antigens
Authors: Pasha R. P. K. , Roohi A. , Shokri F.
Published: December 2004

summary.Human monoclonal antibodies specific for the D antigen of the Rh system are valuable tools for blood group typing and prevention of erythroblastosis. In this study, peripheral blood lymphocytes obtained from an Rh‐negative woman immunized with Rh‐positive fetuses were immortalized with Epstein–Barr virus (EBV), and transformed lymphoblastoid cell lines (LCLs) secreting antibodies to Rh antigens were generated. The presence of specific antibody was assessed by direct haemagglutination using Rh‐positive, papain‐treated red blood cells (RBCs), and the production of human antibody was assayed by enzyme‐linked immunosorbent assay (ELISA). Specificities of the antibodies were determined by a panel of RBCs of known Rh phenotypes. Five LCLs produced antibody specific for the D antigen, and one LCL showed specificity towards the C antigen of the Rh blood group system. High‐titre anti‐Rh antibody‐producing LCLs were subsequently selected and fused with a humanxmouse heteromyeloma cell line. A hybridoma line producing human antibody of the immunoglobulin M (IgM) isotype, which strongly reacted with the D antigen, was established. The hybridoma was cloned, and the monoclone has been stable for growth and antibody production during 8 months of continuous culture, with a mean antibody concentration of 11·5 µg mL−1and haemagglutination titre of 1/20 480. This antibody was not able to agglutinate a sample of native weak D RBCs (Du); however, agglutination was achieved with papain‐treated DuRBCs. Immunoprecipitation of the D antigen by this antibody, followed by Western blot analysis, did not reveal any immobilized D‐specific polypeptide. As this human antibody readily agglutinates D+RBCs in saline, it has the potential to be used as an efficient reagent in routine blood group typing.
Functional impairment caused by lymphatic filariasis in rural areas of South India
Authors: Ramaiah K. D. , Kumar K. N. Vijay , Ramu K. , Pani S. P. , Das P. K.
Published: December 2004

The functional impairment caused by lymphatic filariasis was assessed through qualitative and quantitative methods in rural areas of Tamil Nadu, South India. About 66% of the patients said that their occupational activities were hampered by the disease. They either work fewer hours or alter their activity. Some had completely given up their job. Domestic chores of most of the female patients were also impeded. Most of those affected try to avoid travel. The disability was worse in patients with acute disease. In view of the results of our and other similar studies, the disability‐adjusted life years lost due to lymphatic filariasis must be revised and the public health importance of the disease reassessed. Considerable functional impairment coupled with recent information on economic burden and productivity loss caused by lymphatic filariasis necessitates paying more attention to the control of the disease.
A school‐based approach to the control of urinary schistosomiasis and intestinal helminth infections in children in Matuga, Kenya: impact of a two‐year chemotherapy programme on prevalence and intensity of infections
Authors: Magnussen Pascal , Muchiri Eric , Mungai Peter , Ndzovu Malick , Ouma John , Tosha Saidi
Published: December 2004

A school‐ and chemotherapy‐based urinary schistosomiasis and intestinal helminth infection control programme was conducted in Matuga Division, Kwale District, Coast Province with teachers taking care of diagnosis, treatment and health education. More than 12 000 children in 36 primary schools were included in the 2‐year programme. Results for 20 evaluation schools are presented. Children with haematuria were treated with praziquantel (40 mg/kg) once a year. Within 2 years, the prevalence of haematuria in the schools was reduced from 28% (range 8–68%) to 11.4% (range 3–23%). More than 80% of the schoolchildren were infected with one or more intestinal helminths at baseline. After one year with levamisole mass chemotherapy, single dose (2.5 mg/kg) three times a year (once per school term), the prevalence of Ascaris infection was reduced by 83% from 18% to 3%, but there was no change in pretreatment prevalences of hookworm (57%) and Trichuris (56%) infections. In the second year of the programme, albendazole 600 mg once every six months was administered to the children in 10 randomly selected schools. This resulted in 52% and 23% reductions in prevalences of hookworm and Trichuris infections, respectively, in these schools and a reduction in mean intensity of infection of 52.8% and 50.3%, respectively.
Effect of mass treatments with ivermectin, with only partial compliance, on prevalence and intensity of O. volvulus infection in adults and in untreated 4 and 5 year‐old children in Burundi
Authors: Newell E. D.
Published: December 2004

Between 1991 and 1994, 4 annual treatments with ivermectin were offered to the population of an area hyperendemic for onchocerciasis in the province of Bururi (Burundi). In one place, Kinama, the annual coverage ranged between 40 and 49% of the population. Of 151 persons who were examined there in 1987 and again in 1994, 4 months after the last treatment round, 43 took ivermectin all 4 times, 34 took it 3 times, 35 twice and 17 only once. Although the compliance in this population was incomplete and far from regular, the prevalence of infection in a sample of untreated 4 and 5 year‐old children dropped from 60.0% in 1987 to 23.7% in 1994 (a reduction of 60.5%, P < 0.01) and their microfilarial load (geometric mean number of microfilariae in scarification slides) from 3.0 to 0.4 (a reduction of 86.7%, P <0.01). It appears that even a suboptimal mass distribution of ivermectin can reduce the microfilarial load to a level where the transmission of O. volvulus becomes seriously affected.