bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytotaxonomy of four species in the Simulium perflavum species group (Diptera: Simuliidae) from Brazilian Amazonia
Authors: Hamada Neusa , Adler Peter H. 
Published: March 2003

SummaryPolytene chromosomes of four members of the Simulium perflavum species group in Brazil are described, and a standard map for the species group is presented. Simulium rorotaense Floch & Abonnenc, S. perflavum Roubaud and an undescribed species (S.‘X’) are chromosomally conservative, each representing a single species with a unique preimaginal habitat. Chromosomal, morphological and ecological evidence indicates that S. maroniense Floch & Abonnenc, previously considered synonymous with S. rorotaense, is a good species. Independent morphological and chromosomal analyses yielded 99.4% agreement in separating larvae of S. rorotaense and S. maroniense. The two species can be distinguished by gill morphology or by a subterminal inversion on the long arm of chromosome III. Simulium maroniense consists of at least four cytotypes, each with different sex chromosomes and autosomal polymorphism profiles and associated with a particular landscape type, altitude, temperature regime or geographical location. Simulium rorotaense and S. maroniense share one unique inversion, as do S. perflavum and S. ‘X’, indicating two pairs of sister species. The anthropogenic S. perflavum probably dispersed into Central Amazonia sometime after the mid‐1970s.
Molecular phylogeny of cockroaches (Blattaria) based on mitochondrial COII gene sequences
Authors: Maekawa Kiyoto , Matsumoto Tadao 
Published: March 2003

SummaryPhylogenetic relationships among five cockroach families (Cryptocercidae, Polyphagidae, Blattidae, Blattellidae and Blaberidae) using seventeen species, were estimated based on the DNA sequences of the mitochondrial cytochrome oxidase subunit II (COII) gene. A cladogram inferred using the neighbour‐joining method indicated that Polyphagidae and Cryptocercidae are closely related to each other, and that these two groups are a sister group to the remaining cockroach families. The monophyly of this clade, however, was not strongly supported in terms of bootstrap percentages. Blaberidae and Blattellidae were shown to be sister groups as previously proposed, with Blattidae as a sister group to that clade. Non‐weighted and weighted parsimony analyses were also performed following analyses of nucleotide substitution patterns that indicated saturation of the COII gene among these taxa had occurred. These parsimonious cladograms suggested that Polyphagidae was the basal family, and Polyphaginae, including Cryptocercus as proposed by Grandcolas 1994a), was not monophyletic. The inferred relationships among cockroach families (Polyphagidae, Cryptocercidae + (Blattidae + (Blattellidae + Blaberidae))) is partly in agreement with some previously published analyses. Additionally, based on molecular data, Asian and American Cryptocercus are suggested to have diverged from one another before the Oligocene (∼20 mya).
Phylogenetic analysis of paraneopteran orders (Insecta: Neoptera) based on forewing base structure, with comments on monophyly of Auchenorrhyncha (Hemiptera)
Authors: Yoshizawa Kazunori , Saigusa Toyohei 
Published: March 2003

SummaryPhylogenetic relationships among three paraneopteran clades (Psocodea, Hemiptera and Thysanoptera) were analysed based on the morphology of forewing base structure. Monophyly of Paraneoptera was supported by nine autapomorphies, monophyly of Condylognatha (= Thysanoptera + Hemiptera) by two autapo‐ morphies, monophyly of Thysanoptera by five autapomorphies and monophyly of Hemiptera by one autapomorphy. Thus, (Psocodea + (Thysanoptera + Hemiptera)) were proposed to be the phylogenetic relationships within Paraneoptera. A homoplastic similarity of the third axillary sclerite was observed between Thysanoptera and Heteroptera, and a possible evolutionary factor providing this homoplasy was discussed. The present analysis also suggested a monophyletic Auchenorrhyncha, and reduction of the proximal median plate was considered as an autapomorphy of this clade.
Morphology‐based phylogeny of the treehopper family Membracidae (Hemiptera: Cicadomorpha: Membracoidea)
Authors: Dietrich C. H. , Mckamey S. H. , Deitz L. L. 
Published: March 2003

SummaryA parsimony‐based phylogenetic analysis of eighty‐three morphological characters of adults and immatures of seventy representatives of the tribes and subfamilies of Membracidae and two outgroup taxa was conducted to evaluate the status and relationships of these taxa. Centrotinae apparently gave rise to Nessorhinini and Oxyrhachini (both formerly treated as subfamilies, now syn.n. and syn.reinst., respectively, of Centrotinae). In contrast to previous analyses, a clade comprising Nicomiinae, Centronodinae, Centrodontinae, and the unplaced genera Holdgatiella Evans, Euwalkeria Goding and Antillotolania Ramos was recovered, but relationships within this clade were not well resolved. Nodonica bispinigera, gen.n. and sp.n., is described and placed in Centrodontini based on its sister‐group relationship to a clade comprising previously described genera of this tribe. Membracinae and Heteronotinae were consistently monophyletic. Neither Darninae nor Smiliinae, as previously defined, was monophyletic on the maximally parsimonious cladograms, but constraining both as monophyletic groups required only one additional step. The monophyly of Stegaspidinae, including Deiroderes Ramos (unplaced in Membracidae), was supported on some but not all equally parsimonious cladograms. More detailed analyses of individual subfamilies, as well as morphological data on the undescribed immatures of several membracid tribes and genera, will be needed to elucidate relationships among tribes and genera. A key to the subfamilies and tribes is provided.
Sveconorwegian and Caledonian foreland basins in the Baltic Shield revealed by fission‐track thermochronology
Authors: Larson  , Tullborg  , Cederbom  , Stiberg  
Published: March 2003

Fission‐track thermochronology has been applied to apatite, zircon and titanite from various depths of the Baltic Shield. Burial due to Sveconorwegian (Grenville) and Caledonian foreland sedimentation is revealed.Titanite and zircon fission‐track ages from surface samples (from eastern Sweden) do not vary significantly and average ∼ 850 Myr. It is suggested that Sveconorwegian sediments reached a thickness of at least 8 km in eastern Sweden. Exhumation of these sediments was succeeded by deposition of Lower Palaeozoic cover rocks. Apatite fission‐track ages along a transect from SW to NE across the shield, increase from ∼ 300 Myr to ∼ 900 Myr and yield the Phanerozoic history of subsidence and exhumation. Apatite fission tracks, in the basement of the thickest parts of the foreland basin, were totally annealed. These results suggest a > 600 km wide Caledonian foreland basin filled by Devonian sediments that were > 2.5 km thick in southern and western Sweden, thinning to the east (in Finland).
Characterization of the auxin‐regulated par gene from tobacco mesophyll protoplasts.
Authors: Takahashi Y , Kusaba M , Hiraoka Y , Nagata T 
Published: March 2003

SummaryThe auxin‐regulated par gene from tobacco mesophyll protoplasts was characterized in detail to deduce its possible function. An homology search of the par gene in the NBRF databases revealed that the par gene has homology to the stringent starvation protein (ssp) gene of Escherichia coli, which is induced under starved conditions and binds in an equimolar ratio to a holoenzyme of RNA polymerase. Hence, it is supposed that the par gene product could play a similar role to that of ssp. Although sequence homology of the par gene to the Gmhsp 26‐A gene from soybean was observed, both genes were shown to respond differently to plant hormones and stresses. Gmhsp 26‐A is induced by heat shock, 2,4‐dichlorophenoxyacetic acid (2,4‐D), cytokinin and abscisic acid (ABA), whereas the par gene was induced only by auxins. Furthermore, cycloheximide treatment prevents 2,4‐D‐mediated accumulation of Gmhsp 26‐A mRNA, but not that of par mRNA. Both par and Gmhsp 26‐A respond to CdCl2, but splicing of the par pre‐mRNA proceeded in a normal way, whereas splicing off the Gmhsp 26‐A pre‐mRNA was inhibited. Hence, the par and Gmhsp 26‐A genes should have a common ancestor, but have evolved in different directions. Detailed time‐course experiments confirmed that the par gene was induced immediately after the addition of auxin and expressed upon the initiation of meristematic activity in tobacco mesophyll protoplasts. As the par gene was induced by the sole treatment of cycloheximide, it was proposed that the par gene belongs to a category of 'superinduction' genes.(ABSTRACT TRUNCATED AT 250 WORDS)
A pathogen‐induced gene of barley encodes a protein showing high similarity to a protein kinase regulator.
Authors: Brandt J , Thordal‐Christensen H , Vad K , Gregersen PL , Collinge DB 
Published: March 2003

SummaryA full length cDNA of a barley leaf messenger, found to increase in amount during infection attempts by the powdery mildew fungus (Erysiphe graminis), is characterized. The messenger encodes a polypeptide of 261 amino acid residues with a calculated mass of 29.2 kDa and a pI of 4.6. Sequence comparisons as well as serological studies demonstrate that the encoded protein is closely related to a family of mammalian proteins believed to have functions associated with the multifunctional Ca(2+)‐dependent protein kinases.
Gametophytic and sporophytic expression of an antherspecific Arabidopsis thaliana gene
Authors: Roberts Michael R. , Foster Gary D. , Blundell Robert P. , Robinson Susan W. , Kumar Amar , Draper John , Scott Rod 
Published: March 2003

SummaryGenomic and cDNA clones of the anther‐specific APG gene from Arabidopsis thaliana and Brassica napus1 which encodes a novel proline‐rich protein, were isolated and characterized. Southern blotting and Northern analysis of male fertile and cytoplasmic male sterile varieties of B. napus showed that the APG gene is present as a single copy in the Arabidopsis genome, and that the B. napus APG gene is a member of a small anther‐specific gene family. Analysis of developmentally staged B. napus flower buds indicated that APG transcript is confined to the anther during the period of microspore development. Reporter gene fusions established that the APG promoter directs expression in a number of cell types in anthers of transformed plants. This expression is consistent with the temporal pattern of mRNA accumulation in B. napus buds and follows a complex developmental pattern. Most significantly, the promoter is active in both sporophytic and gametophytic cell types, with activity of the transgene in each cell type being delineated by various cytological markers.
Co‐suppression of the petunia homeotic gene fbp2 affects the identity of the generative meristem
Authors: Angenent Gerco C. , Franken John , Busscher Marco , Weiss David , Van Tunen Arjen J. 
Published: March 2003

SummaryThe function of the petunia MADS box gene fbp2 in the control of floral development has been investigated. Inhibition of fbp2 expression in transgenic plants by a co‐suppression approach resulted in the development of highly aberrant flowers with modified whorl two, three and four organs. This mutant flower phenotype inherited as a single Mendelian trait. The flowers possess a green corolla which is reduced in size. Furthermore, the stamens are replaced by green petaloid structures and the inner gynoecial whorl is dramatically reduced. No ovules or placenta are formed and instead two new inflorescences developed in the axils of the carpels. These homeotic transformations are accompanied by a complete down‐regulation of the petunia MADS box gene fbp6 which is highly homologous to the Arabidopsis and Antirrhinum genes agamous (ag) and plena (ple). In contrast to this, two other petunia MADS box genes, exclusively expressed in whorls two and three, are still transcribed. Our results indicate that the fbp2 gene belongs to a new class of morphogenesis genes involved in the determination of the central part of the generative meristem.
Complex spatial and temporal expression of lipoxygenase genes during Phaseolus vulgaris (L.) development
Authors: Georg Eiben Hans , Slusarenko Alan J. 
Published: March 2003

SummaryA new member (Lox1) of the lipoxygenase (LOX) gene family in French bean was isolated and its specific expression compared to the general expression pattern of related LOX genes. LOX transcripts detected by a French bean cDNA LOX probe were generally abundant in young, developing tissues, and LOX protein, detected on immunoblots showed a similar distribution. Tissue prints showed that cell‐specific, locally high amounts of LOX protein were observed in some tissues, for example in parts of the starch sheath in the hypocotyl and a cell layer in the pericarp.The Lox1 gene from Phaseolus vulgaris was shown in genomic Southerns to be present as a single copy per haploid genome. RNase protection studies showed that the gene is active and the transcription start site was mapped by cDNA primer extension. RNase protection studies showed that Lox1 mRNA was present only in flowers and embryonic primary leaves, in stems and most strongly, in young secondary leaves but not in any of the other organs tested (i.e. not in roots, nodules, hypocotyls, cotyledons, older secondary leaves, pericarp or seeds). Lox1 gene transcripts did not accumulate in leaves in response to methyl jasmonate or pathogen inoculation, even though these treatments caused the accumulation of other LOX transcripts. Thus, the various lipoxygenase genes are regulated differentially during French bean development and in response to different stress stimuli, and possible functions are discussed in view of the specific expression patterns observed.
Carbohydrate binding activities of Bradyrhizobium japonicum III. Lectin expression, bacterial binding, and nodulation efficiency
Authors: Ho Siu‐Cheong , Wang John L. , Schindler Melvin , Loh John T. 
Published: March 2003

SummaryIn previous studies, evidence that the Bradyrhizobium japonicum lectin, designated BJ38, mediated the observed carbohydrate‐specific binding activities of the bacteria, including the saccharide‐specific adhesion to soybean root cells was presented. In the present study, it is found that both B. japonicum, as well as the purified BJ38, bind predominantly to young emergent root hairs of soybean roots and, to a much lesser extent, to the root cap, mature root hairs, epicotyl or hypocotyl regions. Thus, the region of preferential binding for both the bacteria and the isolated lectin coincide with the region of the soybean root most susceptible to B. japonicum infection. The importance of bacterial binding for the nodulation process was studied by comparing the nodulation efficiency of binding‐deficient mutants N4 and N6 to the wild‐type. These mutants had been shown to be defective in carbohydrate recognition, as represented by their diminished ability to bind to soybean roots. BJ38 was immunolocalized to one pole of the cell surface of wild‐type B. japonicum, but no surface labeling could be detected on either mutant. Moreover, both N4 and N6 showed a substantial decrease in nodulation activity, relative to the wild‐type. These results provide additional evidence that the carbohydrate binding activity of B. japonicum, most probably mediated by BJ38, may play an important role(s) in the initial phases of the infection process.
Accumulation of plastid HSP 23 of Chenopodium rubrum is controlled post‐translationally by light
Authors: Debel Karsten , Knack Gaby , Kloppstech Klaus 
Published: March 2003

SummaryThe expression of the 23 kDa plastid heat‐shock protein (HSP) of Chenopodium rubrum has been studied at various light intensities at a temperature of 38°C where the 23 kDa protein accumulates to its highest levels. It was observed that the level of mRNA which is induced at this heat‐shock temperature is independent of the light intensity between 0 and 1000 W m−2. Labelling in vivo of all investigated HSP is also not dependent on the light fluxes applied. In clear contrast the accumulation of the mature chloroplast HSP 23 is light dependent: while almost no protein is detectable in the dark the level of the accumulated protein reaches a maximum at a light intensity of 300 W m−2. The accumulated levels of HSP 23 correlate well with resistance against photoinhibition; photoinhibitory effects are observed at a light intensity of 300 W m−2 or above as measured by the decline of PS II activity.When high light intensities are applied during recovery from heat shock the amounts of HSP 23 stay elevated for a longer time and at a higher level than at the standard light intensity of 10 W m−2. This appears to be a peculiar property of the plastid HSP 23 as the accumulation of HSP 17 and 70, as analysed by Western blot, is not influenced by light. When under particular stress conditions the levels of HSP 23 remain low a protein of 31 kDa accumulates that reacts with the antibody to HSP 23 and might represent the precursor of HSP 23.
A carboxy‐terminal plant vacuolar targeting signal is not recognized by yeast
Authors: Gal Susannah , Raikhel Natasha V. 
Published: March 2003

SummaryThree different classes of signals for plant vacuolar targeting have been defined. Previous work has demonstrated that the carboxyl‐terminal propeptide (CTPP) of barley lectin (BL) is a vacuolar targeting signal in tobacco plants. When a mutant BL protein lacking the CTPP is expressed in tobacco, the protein is secreted. In an effort to determine the universality of this signal, the CTPP was tested for its ability to target proteins to the vacuole of Saccharomyces cerevisiae. Genes encoding fusion proteins between the yeast secreted protein invertase and BL domains were synthesized and transformed into an invertase deletion mutant of yeast. Invertase assays on intact and detergent‐solubilized cells demonstrated that invertase+CTPP was secreted, while nearly 90% of the invertase::BL+CTPP (fusion protein between invertase and BL containing the CTPP) and invertase::BL‐CTPP proteins (fusion between invertase and BL lacking the CTPP) were retained intracellularly. These fusions were secreted in a mutant of yeast that normally secretes proteins targeted to the vacuole. With this and previous work, proteins representing all three classes of plant vacuolar targeting signals have now been tested in yeast, and in all cases, the experiments indicate that the plant proteins are directed to the yeast vacuole using signals other than those recognized by plants.
The maize RNA‐binding protein, MA16, is a nucleolar protein located in the dense fibrillar component
Authors: Albà M. Mar , Culiáñez‐Macià Francisco A. , Goday Adela , Freire Miguel Angel , Nadal Belén , Pagès Montserrat 
Published: March 2003

SummaryA developmentally and environmentally regulated gene in maize, MA16, encoding an RNA‐binding protein that binds preferentially to uridine and guanosine‐rich RNAs has previously been described. To gain some insight into the function of MA16 the distribution of MA16 mRNA and protein during maize development was investigated using in situ hybridization, RNA and protein gel blot analysis and immunocytochemistry. The results show that MA16 is expressed throughout development of the embryo and seedling in different tissues and at different levels. The level of MA16 mRNA is higher in developing and expanding structures such as the root elongation zone and young leaves. After stress treatment MA16 mRNA increases in total and polysomal RNA, but no significant change in the level of the protein was detected. MA16 is a non‐ribosomal nucleolar protein. Using immunoelectron microscopy the MA16 protein has been located in the dense fibrillar component and to a lesser extent in the granular component of the nucleolus. It was found that MA16 contains the conserved sequence motifs R(G)nY(G)nR and RR(E/D)(G)nY(G)n repeated in the C‐terminal of the molecule that conforms imperfectly to the GAR motif proposed for nucleolar proteins. In light of these results the stress regulation of MA16 and a likely role for this protein in pre‐rRNA processing and/or ribosome assembly is discussed.
Reduced variation in transgene expression from a binary vector with selectable markers at the right and left T‐DNA borders
Authors: Bhattacharyya Madan K. , Stermer Bruce A. , Dixon Richard A. 
Published: March 2003

SummaryA new binary vector for Agrobacterium‐mediated plant transformation was constructed, in which two selectable markers, for kanamycin and hygromycin resistance, were placed next to the right and left T‐DNA borders, respectively, and a CaMV 35S promoter‐driven β‐glucuronidase (GUS) gene was placed between these markers as a reporter gene (transgene). Using double antibiotic selection, all transgenic tobacco plants carrying at least one intact copy of the T‐DNA expressed the transgene, and this population exhibited reduced variability in transgene expression as compared with that obtained from the parent vector pBI121. Absence of the intact transgene was the major reason for transgenic plants with little or no transgene expression. Integration of truncated T‐DNAs was also observed among transgenic plants that expressed the transgene and carried multiple T‐DNA inserts. The copy number of fully integrated T‐DNAs was positively associated with transgene expression levels in R0 plants and R1 progeny populations. Variability due to position effect was determined among 17 plants carrying a single T‐DNA insert. The coefficient of variability among these plants was only 35.5%, indicating a minor role for position effects in causing transgene variability. The new binary vector reported here can therefore be used to obtain transgenic populations with reduced variability in transgene expression.
A novel Arabidopsis type 1 protein phosphatase is highly expressed in male and female tissues and functionally complements a conditional cell cycle mutant of Aspergillus
Authors: Arundhati A. , Feiler H. , Traas J. , Zhang H. , Lunness P.A. , Doonan J.H. 
Published: March 2003

Type 1 protein phosphatases are very highly conserved throughout eukaryotes where they regulate a number of key metabolic and morphogenetic processes. A cDNA, AtPP1bg, representing a new member of the type 1 protein phosphatase gene family in Arabidopsis has been isolated on the basis of hybridization with the Aspergillus bimG protein phosphatase gene. The AtPP1bg gene potentially encodes a 37 kDa protein very closely related to PP1 but with divergent N‐ and C‐termini. The predicted amino acid sequence shows 71% identity to the ORF of the bimG gene. When expressed in Aspergillus under the alcA promoter, this phosphatase complements the temperature‐sensitive bimG11 mutation allowing nearly normal vegetative growth at 37°C (but not at 42°C). Notably, the plant PP1 does not support morphogenesis (conidiation) at 37°C. This may indicate that conidophore formation has particular phosphatase requirement(s) which the plant PP1 cannot supply.The pattern of expression of the AtPP1bg transcript has been studied during development of the plant. In situ hybridization of Arabidopsis with antisense probes shows that this phosphatase gene is expressed at a low level throughout the plant, but is strongly upregulated within developing flowers, especially in the tapetum, the developing and mature pollen and in the ovaries. This implies that the AtPP1bg either has a specialized role in the formation of these organs, or that there is an increased requirement for protein phosphatase 1 at these stages. It was found that the level of AtPP1bg transcript, as judged by the relative intensity of staining in different cells within the floral meristems, did not vary during the cell cycle.