bluuebunny/crossref_metadata_2025_split huggingface dataset:
Corazonin gene expression in the waxmoth Galleria mellonella
Authors: Hansen I. A. , Sehnal F. , Meyer S. R. , Scheller K. 
Published: March 2003

AbstractWe cloned and sequenced a full length cDNA coding for [Arg7]‐corazonin in the greater wax moth Galleria mellonella. The deduced corazonin preprohormone consists of a nineteen amino acid signal peptide, the actual eleven amino acid corazonin sequence, followed by a Gly serving for amidation, a Lys‐Arg processing site and an eighty amino acid corazonin precursor‐related peptide. The data confirm the phylogenetic conservation of the actual corazonin sequence. The signal peptide and the precursor‐related peptide exhibit a similar spacing of a few amino acids as detected in the corazonin preprohormone of Drosophila melanogaster. Northern blots and in situ hybridization experiments revealed that the G. mellonella corazonin gene is tissue‐specifically expressed in four pairs of lateral neurosecretory cells in the brains of penultimate and last instar larvae, as well as of pupae and adults. No corazonin mRNA was detected in other cells of the nervous system, fat body, gut, and several other organs.
Ribosomal DNA spacer genotypes of the Anopheles bancroftii group (Diptera: Culicidae) from Australia and Papua New Guinea
Authors: Beebe N. W. , Maung J. , van den Hurk A. F. , Ellis J. T. , Cooper R. D. 
Published: March 2003

AbstractMosquitoes of the Anopheles bancroftii group collected from Northern Australia and Papua New Guinea (PNG) were investigated for sequence variation within the ribosomal DNA ITS2. Wing fringe morphology originally used to identify members of this group was compared to genotypes identified by restriction fragment length polymorphism analysis (RFLP) and heteroduplex analysis (HDA) of the rDNA ITS2. Members of this group separated into four RFLP genotypes (A, B, C and D) with some genotypes displaying wing fringe polymorphisms. Heteroduplex analysis of the ITS2 within and between populations identified genotype A as containing two geographically separate ITS2 sequences: A1 from the Northern Territory of Australia and A2 from Queensland and the Western Province of PNG. Genotypes B and C and genotypes C and D were found sympatric and appeared to be evolving independently suggesting the possibility of cryptic species. Genotype C contained two ITS2 sequence types within the genome.
Transovarial transmission of sugarcane white leaf phytoplasma in the insect vector Matsumuratettix hiroglyphicus (Matsumura)
Authors: Hanboonsong Y. , Choosai C. , Panyim S. , Damak S. 
Published: March 2003

AbstractWhite leaf is a serious disease of sugarcane caused by phytoplasma. The disease is transmitted to the plant by the leafhopper Matsumuratettix hiroglyphicus (Matsumura). The reservoir of phytoplasma was suspected to be weeds that grow in sugarcane farming areas because they can be infected with phytoplasma and show symptoms similar to sugarcane white leaf. However in previous work we have demonstrated by RFLP and sequencing that this is not the case. Here we have reared M. hiroglyphicus through two generations by feeding them phytoplasma free sugarcane grown from tissue culture. By nested‐PCR followed by sequencing, we demonstrated the presence of the phytoplasma in eggs, nymphs and adults of the first and second generations thereby showing transovarial transmission. We have also shown by in situ PCR that phytoplasmas were widely distributed throughout the body of the insect. RFLP and sequencing showed that the same phytoplasma was present in the vector and in the plant. Together, these data point to the leafhopper M. hiroglyphicus as the reservoir of phytoplasma that cause sugarcane white leaf disease.
Lacustrine spatial distribution of landlocked Atlantic salmon populations assessed across generations by multilocus individual assignment and mixed‐stock analyses
Authors: Potvin C. , Bernatchez L. 
Published: March 2003

AbstractThe objective of this study was to assess the spatiotemporal distribution of four landlocked Atlantic salmon (Salmo salar) populations during their sympatric feeding phase in lake St‐Jean (Québec, Canada). A total of 1100 fish captured over a period of 25 years was genotyped at six microsatellite loci in order to assess the temporal stability of the relative proportion of each population in different lake sectors using both individual‐based assignment and mixed‐stock analysis. Estimates of relative proportions obtained from both methods were highly correlated. A nonrandom spatial distribution of populations was observed for each period and, despite the fact that the overall proportion of each population varied over time, the pattern of differential distribution remained generally stable over time. Furthermore, there were indications that the extent of horizontal spatial overlap among populations was negatively correlated with that of their genetic differentiation at both microsatellites and a major histocompatibility complex locus, and independent of the geographical distance between the rivers of origin. We discuss the hypothesis that the temporal stability of spatial distribution, the lack of an association between spatial partitioning and geographical distance between rivers of origin, and the apparent negative correlation between spatial overlap and genetic differentiation, reflect the outcome of selective pressures driving behavioural differences for spatial niche partitioning among populations.
Host and geographical factors influence the thermal niche of enteric bacteria isolated from native Australian mammals
Authors: Okada Shoko , Gordon David M. 
Published: March 2003

AbstractThe thermal profiles of 118 bacterial strains, representing six species of the family Enterobacteriaceae, isolated from a variety of native Australian mammals were determined under in vitro conditions. Each of the bacterial species had a unique thermal profile and differed in their minimum or maximum temperature for growth and in their response to changing temperatures. The taxonomic classification of the host from which the bacterial strains were isolated explained a significant amount of the variation in thermal profile among strains of a species. Host effects were detected at all taxonomic levels: order, family, genus, and species. The locality (State or Territory) or climate zone from which the strain was collected explained a significant amount of the variation in the thermal profile of Citrobacter freundii, Enterobacter cloacae and Klebsiella pneumoniae strains. Genetically similar strains, as determined by allozyme profiles, had similar thermal profiles for the bacterial species Hafnia alvei and Escherichia coli. The results of this study indicate that there are potentially many aspects of host biology that may determine the thermal profile of these bacteria.
Contrasting evolutionary forces driving population structure at expressed sequence tag polymorphisms, allozymes and quantitative traits in white spruce
Authors: Jaramillo‐Correa J. P. , Beaulieu J. , Bousquet J. 
Published: March 2003

AbstractPatterns of variation in quantitative characters and genetic markers were compared among six regional populations of white spruce [Picea glauca (Moench) Voss]. Although some phenotypic characters were correlated with latitude (r = 0.791), longitude (r = −0.796) and precipitation during the growing season (r = 0.789), variability at genetic markers was not correlated with geographical or bioclimatic variables, and followed neutral expectations. Estimates of genetic diversity and population differentiation for 14 allozymes (translated regions of coding genes) were essentially indistinguishable from those observed for 11 expressed sequence tag polymorphisms (ESTPs) from untranslated regions of coding genes. Variation among populations for quantitative traits such as eighth year height (QST = 0.082), thirteenth year height (QST = 0.069), total wood density (QST = 0.102) and date of budset (QST = 0.246), was greater than for allozymes (GST = 0.014) and ESTPs (GST = 0.019). These trends suggest a strong adaptive response in quantitative traits, contrasting to allozymes and ESTPs where no selective response could be detected and where populations appeared to be essentially in a migration–drift equilibrium.
Barriers to gene flow from oilseed rape (Brassica napus) into populations of Sinapis arvensis
Authors: Moyes C. L , Lilley J. M , Casais C. A , Cole S. G , Haeger P. D , Dale P. J 
Published: March 2003

AbstractOne concern over growing herbicide‐tolerant crops is that herbicide‐tolerance genes may be transferred into the weeds they are designed to control. Brassica napus (oilseed rape) has a number of wild relatives that cause weed problems and the most widespread of these is Sinapis arvensis (charlock). Sinapis arvensis seed was collected from 102 populations across the UK, within and outside B. napus‐growing areas. These populations were tested for sexual compatibility with B. napus and it was found that none of them hybridized readily in the glasshouse. In contrast to previous studies, we have found that hybrids can be formed naturally with S. arvensis as the maternal parent. Six diverse B. napus cultivars (Capricorn, Drakkar, Falcon, Galaxy, Hobson and Regent) were tested for their compatibility with S. arvensis but no cultivar hybridized readily in the glasshouse. We were unable to detect gene transfer from B. napus to S. arvensis in the field, confirming the extremely low probability of hybridization predicted from the glasshouse work.
Patterns of genetic and phenotypic variation inIris hayneiandI. atrofusca(Irissect.Oncocyclus = the royal irises) along an ecogeographical gradient in Israel and the West Bank
Authors: Arafeh R. M. H , Sapir Y , Shmida A , Iraki N , Fragman O , Comes H. P 
Published: March 2003

AbstractIris hayneiandI. atrofuscaare two closely related narrow endemics distributed vicariously along an ecogeographical north–south gradient in Israel and the West Bank. To obtain baseline information of the taxonomic status, conservation and population history of these taxa, we investigated patterns of phenotypic variation and the partitioning of genetic variation within and among populations using dominant random amplified polymorphic DNA (RAPD) markers. Multivariate (principal components analysis) and taxonomic distance analyses based on morphometric traits from eight populations revealed no unambiguous separation into two distinct groups. Results of genetic analyses for nine populations differed only slightly when either allele‐ or marker‐based approaches were employed. Mean within‐population diversity was high (0.258 for Nei’s expected heterozygosity), but there was no significant relationship between genetic diversity and either population size or latitude. Although the range‐wide estimate ofGST(≈ 0.20) revealed relatively high differentiation among populations this value was inflated because of a small, but significant, component of molecular variance among regions viz. taxa (≈ 5%). Limited long‐distance dispersal capabilities in conjunction with a linearized habitat distribution are proposed to contribute to the approximate isolation by distance pattern observed. It also appears that extant populations are currently deviating from equilibrium conditions because of primary divergence of a formerly more widespread ancestral population. Given the absence of deep genetic and phenotypic subdivision among northern (I. haynei) vs. central/southern (I. atrofusca) populations, we argue for a revision of their species status. Nonetheless, we recommend conservation attention to these geographically differentiated segments as separate management units, which can be seen as an instructive example of incipient species formation.
Genetic structure of natural populations of the grass endophyteEpichloë festucaein semiarid grasslands
Authors: Arroyo García R. , Martínez Zapater J. M. , García Criado B. , Zabalgogeazcoa I. 
Published: March 2003

AbstractPlants of red fescue (Festuca rubra), a commercially important turf grass, are infected by the fungal endophyteEpichloë festucaein semiarid natural grasslands, known as dehesas, in western Spain. We used amplified fragment length polymorphism (AFLP) markers to analyse the genetic polymorphism existing in two natural populations ofEpichloë festucae. Linkage disequilibrium and the presence of clonal lineages indicated that nonrecombinant asexual reproduction predominates in both populations. However, most genetic variation detected was found to occur within populations, with only a moderate amount of genetic differentiation between populations (FST: 0.197). Overall, the study suggests that dehesa grasslands are useful reservoirs ofEpichloë festucaeendophytes, and provides information on population structure which is relevant to design sampling strategies.
Correlation of risk categorization in gestational trophoblastic tumor between old and new combined staging and scoring system
Authors: Tocharoenvanich Sathana , Chichareon Saibua , Wootipoom Virach , Bu‐ngachat Rakchai , Piyananjarassri Karantarat 
Published: March 2003

AbstractAim:  To determine the correlation of risk categorization in gestational trophoblastic tumor between the revised International Federation of Gynecology and Obstetrics (FIGO) staging system combined with the original World Health Organization (WHO) scoring system, and the new FIGO staging system combined with the modified WHO scoring system.Methods:  We reviewed the medical records of 124 patients with gestational trophoblastic disease seen at Songklanagarind Hospital from 1988 to 2000. All patients were classified retrospectively by the FIGO staging system (both the revised system in 1992 and the new system in 2000) and the WHO scoring system (both the original and the modified one). The correlation of risk categorization between the revised FIGO staging system combined with the original WHO scoring system (old combined system), and the new FIGO staging system combined with the modified WHO scoring system (new combined system) was studied, and the remission rates in discrepant groups were identified.Results:  The mean score was 9.7 ± 5.0 (range 1–21) for the original WHO and 8.3 ± 5.0 (range 1–20) for the modified WHO. The correlation of risk categorization between old and new combined systems was 97.9%. There was no patient in the low risk group as classified by the old combined system, but patients were classified as in the high risk group by the new combined system. One patient, who was in the high risk group classified by the old combined system, but in the low risk group classified by the new combined system, achieved complete remission after treatment with single agent chemotherapy.Conclusion:  There was good correlation between the old and the new combined systems.
Regulation of pathogenic development in the corn smut fungus Ustilago maydis
Authors: Grandel Annemarie , Romeis Tina , Kämper Jörg 
Published: March 2003

AbstractIn Ustilago maydis, the b mating type locus constitutes the central regulatory domain for pathogenic development. The b locus encodes two homeodomain proteins that are thought to function as transcriptional regulators. Here we describe our current view of the different regulatory pathways in which the b locus is involved. We emphasize on the development of tools for the isolation of genes that are directly regulated by b homeodomain proteins.
Pararetrovirus–crucifer interactions: attack and defence or modus vivendi?
Authors: Covey Simon N. , McCallum Don G. , Turner David S. , Al‐Kaff Nadia S. , Dale Philip , Cecchini Edi , Milner Joel J. 
Published: March 2003

AbstractThe compatible infection of plants by viruses usually leads to the development of systemic symptoms. Symptom expression of this kind is generally understood to be a host response that indicates an inability of the host to defend itself from attack. We have been studying compatible interactions between the plant pararetrovirus cauliflower mosaic virus (CaMV) and its crucifer hosts in order to understand the relationship between viral activity, symptom expression and plant defence. A CaMV protein (P6) appears to play a major role in eliciting symptom expression. This host response leads to a regulation of the viral multiplication cycle that is associated with leaf mosaics. The host regulation of CaMV appears to operate at the transcriptional level through an effect on the 35S promoter, or at the post‐transcriptional level by a process that is akin to gene silencing, and can lead to host recovery depending upon the genetic background of the host. The plant apex is a focus for antiviral defence mechanisms, presumably because viral infection of the apical meristem would rapidly compromise the ability of the plant to generate new leaves and flowers for reproduction. The balance of interactions between CaMV and crucifers can provide a sustainable source of host plants to ensure viral propagation and viral exposure allows the host to adapt and develop its repertoire of defence mechanisms.
From host recognition to T‐DNA integration: the function of bacterial and plant genes in the Agrobacterium–plant cell interaction
Authors: Tzfira Tzvi , Citovsky Vitaly 
Published: March 2003

Abstract Agrobacterium tumefaciens and its related species, A. rhizogenes and A. vitis, are the only known bacterial pathogens which ‘genetically invade’ host plants and stably integrate part of their genetic material into the host cell genome. Thus, A. tumefaciens has evolved as a major tool for plant genetic engineering. Furthermore, this unique process of interkingdom DNA transfer has been utilized as a model system for studies of its underlying biological events, such as intercellular signalling, cell‐to‐cell DNA transport, protein and DNA nuclear import and integration. To date, numerous bacterial proteins and several plant proteins have been implicated in the A. tumefaciens–plant cell interaction. Here, we discuss the molecular interactions among these bacterial and plant factors and their role in the A. tumefaciens–plant cell DNA transfer. Taxonomic relationship: Bacteria; Proteobacteria; alpha subdivision; Rhizobiaceae group; Rhizobiaceae family; Agrobacterium genus. Microbiological properties: Gram‐negative, nonsporing, motile, rod‐shaped, soil‐borne. Related species:
A. rhizogenes (causes root formation in infected plants), A. vitis (causes gall formation on grapevines). Disease symptoms: Formation of neoplastic swellings (galls) on plant roots, crowns, trunks and canes. Galls interfere with water and nutrient flow in the plants, and seriously infected plants suffer from weak, stunted growth and low productivity. Host range: One of the widest host ranges known among plant pathogens; can potentially attack all dicotyledonous plant species. Also, under controlled conditions (usually in tissue culture), can infect, albeit with lower efficiency, several monocotyledonous species. Agronomic importance: The disease currently affects plants belonging to the rose family, e.g. apple, pear, peach, cherry, almond, roses, as well as poplar trees (aspen). Useful web site:
http://www.bio.purdue.edu/courses/gelvinweb/gelvin.html
Erwinia amylovora: the molecular basis of fireblight disease
Authors: Eastgate Julie A. 
Published: March 2003

Summary Taxonomy: Bacteria; Proteobacteria; γ subdivision; order Enterobacteriales; family Enterobacteriaceae; genus Erwinia. Microbiological properties: Gram‐negative, motile rods. Related species:
E. carotovora (soft‐rot diseases), E. chrysanthemi (soft‐rot diseases), E. (Pantoea) stewartii (Stewart’s wilt of corn), E. (Pantoea) herbicola (epiphyte). Host range: Affects rosaceous plants, primarily members of the Pomoideae. Economically important hosts are apple and pear. The commercial implications of fireblight outbreaks are aggravated by the limited effectiveness of current control measures. Disease symptoms:
E. amylovora infection is characterized by water soaking of infected tissue, followed by wilting and tissue necrosis. Necrosis gives tissue a scorched, blackened appearance, giving rise to the name fireblight. Symptoms are often localized to blossom bracts or young shoots but, in highly susceptible hosts, can spread systemically resulting in death of the entire tree. Infections can vary in severity depending on climatic conditions and host susceptibility. Useful web site:
http://www.agric.gov.ab.ca
Characterization of Alternaria alternata glucanase genes expressed during infection of resistant and susceptible persimmon fruits
Authors: Eshel Dani , Lichter Amnon , Dinoor Amos , Prusky Dov 
Published: March 2003

SummaryPreharvest treatment with gibberellic acid (GA3) or its inhibitor paclobutrazol (PBZ) can reduce or increase, respectively, the susceptibility of persimmon fruits to Alternaria alternata. This was suggested to be the result of the ability of the fungus and produced endoglucanases to induce symptom development. To evaluate the importance of glucanases during A. alternata attack, five glucanase genes, corresponding to the C, F, and K families, were cloned from A. alternata using ‘family‐specific’ oligonucleotide primers. The genes, present in a single copy, encode for exoglucanases AaC1 and AaC2, endoxylanase AaF1, endoglucanase AaK1, and the mixed‐linked glucanase AaMLG1. Reverse transcriptase polymerase chain reaction (RT‐PCR) analysis of RNA extracted from persimmon fruits, 2 and 4 days post‐infection with A. alternata, showed the expression of all five glucanase genes in GA3‐ and PBZ‐treated fruits. However, transcription levels and enzyme production of the endoglucanase (AaK1) and one exoglucanase (AaC1) were enhanced during A. alternata growth on cell walls from susceptible PBZ‐treated fruits, whereas the expression of these genes and their enzyme production were significantly reduced in resistant GA3‐treated fruits. The present results suggest the involvement of endo‐ and exoglucanase in symptom development caused by A. alternata in resistant and susceptible persimmon fruits.
Live and let live: insights into powdery mildew disease and resistance
Authors: Panstruga Ralph , Schulze‐Lefert Paul 
Published: March 2003

SUMMARYPowdery mildew is a common fungal disease of many monocotyledonous and dicotyledonous plant species. In a moderately temperate and humid climate, these ascomycete fungi cause severe yield losses in a wide range of crops. In recent years, several plant genes encoding proteins that control disease resistance against powdery mildew were isolated from the model organism Arabidopsis and the crop barley. Here we review the presumptive biochemical functions of the respective proteins and discuss potential mechanisms which mediate pathogen recognition, resistance signalling, and the termination of host colonization. Perhaps not surprisingly, these advances also promise to shed light on the molecular basis of pathogenesis and biotrophic lifestyle.