bluuebunny/crossref_metadata_2025_split huggingface dataset:
The reproductive biology of Polytrichum formosum: clonal structure and paternity revealed by microsatellites
Authors: Van der Velde M. , During H. J. , Van de Zande L. , Bijlsma R. 
Published: March 2003

AbstractUsing highly polymorphic microsatellite markers, we assessed clonal structure and paternity in a population of the bryophyte species Polytrichum formosum. Identical multilocus genotypes of individual shoots were almost never observed in spatially separated cushions, but were found to be highly clustered within moss cushions. Therefore, asexual reproduction through dispersal of gametophyte fragments is not very important in P. formosum. However, asexual reproduction on a very localized scale through vegetative growth of genets (branching of gametophytes via clonal growth of rhizomes) is very extensive. The patchy spatial distribution of genets and the absence of intermingling among genets suggest that this species follows a ‘phalanx’ clonal growth strategy. Vegetative proliferation of genets will increase their size, and, consequently, will have considerable fitness consequences for individuals in terms of increased genet longevity and reproductive output. Although paternity analysis of sporophytes confirmed male genet size, i.e. gamete production, to be an important determinant of male reproductive fitness, it also showed that the spatial distance to female genets is the predominant factor that governs male reproductive success. Moreover, we showed that male gamete dispersal distances in P. formosum are much further than generally assumed, and are in the order of metres rather than centimetres. Combining the findings, we conclude that the high genotypic diversity observed for this facultatively clonal species is most likely explained by a preponderance of sexual reproduction over clonal reproduction.
High within‐population mitochondrial DNA variation due to microvicariance and population mixing in the land snailEuhadra quaesita(Pulmonata: Bradybaenidae)
Authors: Watanabe Y. , Chiba S. 
Published: March 2003

AbstractA high level of geographical variation at an exceptionally fine scale was detected in the mitochondrial 16Sribosomal RNA genes of a land snail speciesEuhadraquaesitafrom the Kanto region of Japan. In total, 50 haplotypes were detected from 27 populations, with most sample sites possessing private alleles. In some individual populations the different haplotypes do not fall as a monophyletic group, so that some of the haplotypes are phylogenetically distant, differing from each other by > 10%. In contrast, phylogenetically similar haplotypes were found in separate sites at long distances from their main distribution. Together, these findings strongly suggest that contraction and expansion of populations has occurred repeatedly in the past. The subsequent expansion of populations and migration from different areas may have mixed distant populations. This repetition of isolation and mixing has resulted in an exceptionally fine scale of geographical variation, and the accumulation of high genetic diversity within and between populations of this species.
A genetic analogue of ‘mark–recapture’ methods for estimating population size: an approach based on molecular parentage assessments
Authors: Pearse D. E. , Eckerman C. M. , Janzen F. J. , Avise J. C. 
Published: March 2003

AbstractMolecular polymorphisms have been used in a variety of ways to estimate both effective and local census population sizes in nature. A related approach for estimating the current size of a breeding population, explored here for the first time, is the use of genetic ‘marks’ reconstructed for otherwise unknown parents in paternity or maternity analyses of progeny arrays. This method provides interesting similarities and contrasts to traditional mark–recapture methods based on physical tags. To illustrate, this genetic method is applied to a population of painted turtles on the Mississippi River to estimate the number of successfully breeding males. Non‐genetic mark–recapture approaches were also applied to animals trapped at this location. Results demonstrate that such genetic data on parentage can be helpful not only in estimating contemporary population sizes, but also in providing additional information, not present in customary mark–recapture data, about possible extended movements of breeding individuals and the size of the pool of mates which they encounter.
A case of successful management of maternal septic shock with multiple organ failure following amniocentesis at midgestation
Authors: Hamanishi Junzo , Itoh Hiroaki , Sagawa Norimasa , Nakayama Takahiro , Yamada Shigetoshi , Nakamura Kaoru , Saito Ayaka , Kumakura Erika , Yura Shigeo , Fujii Shingo 
Published: March 2003

AbstractMaternal sepsis is an unusual but catastrophic complication of amniocentesis. We report a case of successful treatment of maternal septic shock and multiple organ failure following amniocentesis at midgestation, possibly due to needle puncture of the sigmoid colon, which was tightly adherent to the anterior surface of the pregnant uterus.
A dsbA mutant of Pseudomonas syringae exhibits reduced virulence and partial impairment of type III secretion
Authors: Kloek Andrew P. , Brooks David M. , Kunkel Barbara N. 
Published: March 2003

AbstractTo identify virulence genes of P. syringae pv. tomato strain DC3000 we screened for mutants with reduced virulence on its plant hosts, Arabidopsis thaliana and tomato. We isolated a Tn5‐insertion mutant that exhibited reduced virulence on both hosts. Further characterization showed that this mutant carried a single Tn5 insertion in the dsbA gene, which encodes a periplasmic disulphide bond‐forming protein. In addition to reduced virulence, the dsbA mutant exhibits mucoid colony morphology, loss of fluorescence, decreased motility, and a reduced growth rate in culture. The dsbA mutant is able to multiply in A. thaliana and tomato plants, trigger the hypersensitive response on tobacco and elicit Pto‐mediated resistance in tomato, indicating that type III secretion occurs in this background. However, type III secretion appears to function with reduced efficiency in the dsbA mutant, as type III‐dependent secretion of HrpZ and AvrRpt2 is impaired. These findings indicate that while the dsbA gene is required for multiple cellular functions in P. syringae, type III secretion in P. syringae is only partially dependent on dsbA.
Mutations in Ror1 and Ror2 genes cause modification of hydrogen peroxide accumulation in mlo‐barley under attack from the powdery mildew fungus
Authors: Hückelhoven Ralph , Trujillo Marco , Kogel Karl‐Heinz 
Published: March 2003

AbstractRace nonspecific resistance of barley against the barley powdery mildew fungus (Blumeria Graminis f.sp. Hordei, Speer, Bgh) is mediated by recessive mlo alleles and is controlled by at least two additional genes ‘required for ml
o‐specified disease
resistance’ (Ror1 and Ror2). The pathogenesis‐related accumulation of hydrogen peroxide (H2O2) was comparatively analysed in a susceptible barley line (Hordeum vulgare L. Cv Ingrid, genotype Mlo Ror1, Ror2), a resistant Ingrid backcross line carrying the mutant allele mlo5 (BCIngrid‐mlo5, genotype mlo5 Ror1 Ror2), and in the moderately susceptible mutants A44 and A89 (genotypes mlo5 Ror1 ror2 and mlo5 ror1‐2 Ror2, respectively). In situ localization of H2O2 was performed by microscopic detection of 3,3‐diaminobenzidine (DAB) polymerization. In BCIngrid‐mlo5, penetration resistance against Bgh attack was closely correlated to H2O2 accumulation in cytoplasmic aggregates and cell wall appositions beneath the appressorium. In contrast, H2O2 accumulation was almost completely absent in susceptible Ingrid. Lines with mutations in Ror genes showed less H2O2 accumulation beneath appressoria, but more interaction sites with whole cell H2O2 accumulation and hypersensitive cell death response than resistant BCIngrid‐mlo5. Thus, mutations in Ror1 or Ror2 genes influence the cellular pattern of H2O2 accumulation in mlo plants attacked by Bgh. The data support the hypothesis that H2O2 accumulation is involved in resistance to fungal penetration.
DNA microarrays: new tools in the analysis of plant defence responses
Authors: Kazan Kemal , Schenk Peer M. , Wilson Iain , Manners John M. 
Published: March 2003

SummaryLarge‐scale DNA sequencing is providing information on the number and organization of genes and genomes of plant species and their pathogens. The next phase is to identify gene functions and gene networks with key roles in compatible and incompatible plant–pathogen interactions. DNA microarrays can provide information on the expression patterns of thousands of genes in parallel. The application of this technology is already revealing new features of plant–pathogen interactions and will be a key tool for a wide range of experiments in molecular plant pathology.
Pto update: recent progress on an ancient plant defence response signalling pathway
Authors: Bogdanove Adam J. 
Published: March 2003

SummaryThe Pto resistance gene in a gene‐for‐gene interaction with the avrPto avirulence gene governs resistance to bacterial speck of tomato. A member of a small gene family in tomato, Pto encodes a serine/threonine kinase that interacts in the yeast two‐hybrid system with the product of avrPto, an 18‐kDa hydrophilic protein. Over the past decade, studies of these genes, their products, and the defence response signalling pathway they govern have led to significant advances in our understanding of the biochemistry of Pto, the bacterial delivery and Pto recognition specificity for AvrPto, and candidate components in the pathway and their potential functions. This article provides an update of recent advances, which include the discovery of AvrPto structure–function relationships in disease and resistance, discovery of a second avirulence protein (AvrPtoB) recognized by Pto and its limited similarity to AvrPto, expression analysis and functional characterization of transcription factors Pti4, Pti5, and Pti6 that interact with Pto, analyses of Pto over‐expression that activates defence responses independent of AvrPto, and comparisons of Pto gene family members and homologues in tomato and other Solanaceae, as well as other plant species. These comparisons, in particular, have provided exciting new insight into the antiquity of the Pto gene family and of the capacity for specific recognition of AvrPto that activates plant defence.
Mining the enzymes involved in the detoxification of reactive oxygen species (ROS) in sugarcane
Authors: Kurama Eiko E. , Fenille Roseli C. , Rosa Vicente E. , Rosa Daniel D. , Ulian Eugenio C. 
Published: March 2003

SummaryAdopting the sequencing of expressed sequence tags (ESTs) of a sugarcane database derived from libraries induced and not induced by pathogens, we identified EST clusters homologous to genes corresponding to enzymes involved in the detoxification of reactive oxygen species. The predicted amino acids of these enzymes are superoxide dismutases (SODs), glutathione‐S‐transferase (GST), glutathione peroxidase (GPX), and catalases. Three MnSOD mitochondrial precursors and 10 CuZnSOD were identified in sugarcane: the MnSOD mitochondrial precursor is 96% similar to the maize MnSOD mitochondrial precursor and, of the 10 CuZnSOD identified, seven were 98% identical to maize cytosolic CuZnSOD4 and one was 67% identical to putative peroxisomal CuZnSOD from Arabidopsis. Three homologues to class Phi GST were 87–88% identical to GST III from maize. Five GPX homologues were identified: three were homologous to cytosolic GPX from barley, one was 88% identical to phospholipid hydroperoxide glutathione peroxidase (PHGPX) from rice, and the last was 71% identical to GPX from A. thaliana. Three enzymes similar to maize catalase were identified in sugarcane: two were similar to catalase isozyme 3 and catalase chain 3 from maize, which are mitochondrial, and one was similar to catalase isozyme 1 from maize, whose location is peroxisomal subcellular. All enzymes were induced in all sugarcane libraries (flower, seed, root, callus, leaves) and also in the pathogen‐induced libraries, except for CuZnSOD whose cDNA was detected in none of the libraries induced by pathogens (Acetobacter diazotroficans and Herbaspirillum rubrisubalbicans). The expression of the enzymes SOD, GST, GPX, and catalases involved in the detoxification was examined using reverse transcriptase‐polymerase chain reaction in cDNA from leaves of sugarcane under biotic stress conditions, inoculated with Puccinia melanocephala, the causal agent of sugarcane rust disease.
In planta induced genes of Puccinia triticina
Authors: Thara Venkatappa K. , Fellers John P. , Zhou Jian‐Min 
Published: March 2003

SUMMARYWheat leaf rust disease, caused by the biotrophic fungus Puccinia triticina, is a result of complex interactions requiring the coordinated activities of the two organisms involved. In an effort to understand the molecular basis of wheat–rust interactions, we isolated and characterized cDNA corresponding to in planta induced fungal genes (PIGs) from susceptible wheat leaves infected with P. triticina by using suppression subtractive hybridization to construct a cDNA library. 350 clones were sequenced, of which 104 were unique. Forty‐four cDNA clones encode ribosomal proteins, comprising the single largest category of clones isolated. Twenty‐five of these ribosomal protein genes are likely to be of fungal origin, as was suggested by sequence homology. Hybridization of 56 selected non‐ribosomal protein clones to rust germling cDNA or genomic DNA probes showed that at least 44 were of fungal origin, demonstrating that the library was highly enriched for fungal cDNA. Differential expression analysis identified 26 non‐ribosomal protein genes that were induced in rust‐infected leaves. At least 21 of the induced genes were from the rust fungus, indicating that the majority of the induced genes were rust PIGs that are likely to play a role in parasitism. Some of the induced genes share homology to known PIGs or virulence genes in other fungi, suggesting similarities in parasitism among different fungi. Eight clones correspond to novel PIGs that have not been reported in any organism. This paper reports, for the first time, the isolation of P. triticina PIGs and discusses the use of total rust genomic DNA to identify the source of genes.
Detecting and differentiating Acremonium implicatum: developing a PCR‐based method for an endophytic fungus associated with the genus Brachiaria
Authors: Kelemu Segenet , Dongyi Huang , Guixiu Huang , Takayama Yuka 
Published: March 2003

SUMMARY Brachiaria
is a pan‐tropical genus of grasses with about 100 species. The fungus
Acremonium implicatum
can develop an endophytic association that is mutually beneficial with
Brachiaria
species. We developed a polymerase chain reaction (PCR)‐based method by first amplifying DNA from
A. implicatum
isolates using the Random amplified polymorphic DNA (RAPD) technique with arbitrary 10‐mer primers. A 500‐bp PCR product, amplified with primer OPAK‐10 and common to
A. implicatum
isolates, was selected for further evaluation. The fragment was digoxygenin‐labelled and used to probe a dot blot containing genomic DNA from isolates of
A. implicatum
and non‐endophytic fungi, and from
Brachiaria
species free of endophytes. Strong signals were obtained only for DNA from
A. implicatum
isolates. This fragment was cloned and subsequently sequenced. Based on the sequence data, two primers were selected and synthesized: P1 (5′‐TTCGAATGATAAGGCAGATC‐3′) and P4 (5′‐ACGCATCCACTGTATGCTAC‐3′). The primer pair amplified a single fragment of about 500 bp from DNA of
A. implicatum
isolates, whether from pure culture or in association with
Brachiaria
plants. No amplification product was detected in DNA from endophyte‐free plants, pathogenic fungi, the bacterium
Xanthomonas campestris
pv.
graminis
, or non‐pathogenic fungi associated with
Brachiaria
. This assay thus allows the precise and rapid detection of endophytes in
Brachiaria plants and permits a differentiation between endophytic and non‐endophytic fungi.
Predicting safety and quality parameters for UHT‐processed milks
Authors: Browning Emma , Lewis Mike , MacdougalL Douglas 
Published: March 2003

A spreadsheet was developed to evaluate safety and quality parameters for milks subjected to different heating and cooling profiles and holding time conditions in a continuous heat exchanger. Safety parameters evaluated were lethality ( Fo) and microbial inactivation (

B*) values; quality parameters were chemical change (

C*), thiamin loss, lactulose formation, Maillard browning and hydroxymethylfurfural (HMF) formation. The spreadsheet was used to predict these parameters for a pilot plant, heating milks at 120–150°C for 4, 27 and 58 s, using its heating and cooling profiles. Milks were processed in the same plant at these conditions and a selection of the milks were analysed to establish the validity of the spreadsheet. All samples with a

C* value < 3 gave a positive Aschaffenburg turbidity. The activation energy that gave the best agreement between the predicted and experimental results for lactulose was found to be 122 kJ/mol. One set of optimized conditions for this product was 135°C for 10 s, giving

B* = 1.24 and

C* = 0.55. This milk was compared with two others and its sensory characteristics were similar to that with a

C* of 1.5 but different to that with a

C* value of 6. Browning was only found to be noticeable in the most severely heat‐treated sample immediately after processing, but would become apparent on storage at 30°C and above. The spreadsheet is useful for comparing the characteristics of products from plants with different heating profiles or as a means for optimizing UHT plant performance where the heating and cooling rates are fixed.
Up‐regulation of lysozyme production in colonic adenomas and adenocarcinomas
Authors: Yuen  , Wong  , Chung  , Chan  , Cheung  , HO  , Leung  
Published: March 2003

Aims:The presence of lysozyme protein in some gastric adenomas and adenocarcinomas has been well documented. There have been relatively few studies investigating the presence of lysozyme in tumours of the large intestine and they show contrasting results. We aim to investigate the cellular source and expression of lysozyme in colonic adenomas and adenocarcinomas.Methods and results:We randomly selected 29 and 27 colonic adenomas and adenocarcinomas, respectively. Using in‐situ hybridization (ISH) and immunohistochemistry (IHC), we found an up‐regulation of lysozyme in the dysplastic epithelium of all the adenomas studied, with more than 80% of cases expressing moderate to strong signals. Although the up‐regulation of lysozyme was also observed in adenocarcinomas, only 30% of the cases showed moderate to strong signals, mostly with an uneven distribution. Down‐regulation of lysozyme in the severely dysplastic and invasive foci were noted in some cases of adenoma with malignant transformation. Normal colonic glands were consistently negative for lysozyme at both the mRNA and the protein level, but inflamed and immature regenerative colonic epithelium at the crypt base showed positive signals in a similar pattern to those observed in the dysplastic epithelium of the adenomas.Conclusions:Our results confirm that colonic epithelium can produce lysozyme and its expression is up‐regulated in the dysplastic epithelium in adenomas and in invasive cancer cells. It is interesting that regenerative colonic epithelium showed a similar pattern of lysozyme expression as in adenomas. The loss of lysozyme secreting phenotype in most of the invasive tumours suggests that lysozyme may not confer an advantage to tumour progression.
Analysis of CD44 expression in serous and mucinous borderline tumours of the ovary: comparison with cystadenomas and overt carcinomas
Authors: Darai  , Walker‐Combrouze  , Fauconnier  , Madelenat  , Potet  , Scoazec  
Published: March 2003

Aims:To determine the diagnostic and prognostic value of the immunohistochemical analysis of CD44 variants in benign borderline and malignant tumours of the ovary.Methods and results:The reactivity of tumour cells with three monoclonal antibodies, respectively, directed to all CD44 variants, CD44‐v3 isoform and CD44‐v6 isoform, was assessed by using an indirect immunoperoxidase technique applied to formalin‐fixed, paraffin‐embedded samples of 36 cases of borderline, as compared to 20 cases of benign tumours and 20 cases of carcinomas. CD44 variants were detected in 97% of borderline tumours, as compared to 60% of benign tumours and 100% of carcinomas. CD44‐v3 was detected in 25% of borderline tumours, as compared to 0% of benign tumours (P = 0.003) and 55% of carcinomas (P = 0.065). The expression of CD44‐v6 was detected in 28% of borderline tumours, as compared to 20% of benign tumours and 30% of carcinomas. In borderline tumours, as in carcinomas, CD44‐v6, but not CD44‐v3, expression was correlated with an increased proliferative index and with a higher incidence of p53 expression.Conclusion:Borderline tumours of the ovary present frequent quantitative and qualitative alterations in the pattern of expression of CD44 proteins. However, these alterations are unlikely to represent useful diagnostic or prognostic markers.
Alpha‐1‐antichymotrypsin immunoreactivity in papillary carcinoma of the thyroid gland
Authors: Lai M L , Rizzo N , Liguori C , Zucca G , Faa G 
Published: March 2003

AimPapillary thyroid carcinoma (PTC) is the most common malignant tumour of the thyroid gland. The immunohistochemical profile of PTC is characterized by immunoreactivity of tumour cells for cytokeratins, thyroglobulin, vimentin, EMA and S100 protein. Recently, the presence of a serum protease inhibitor, alpha‐1‐antitrypsin (A1AT), has been demonstrated in tumour cells of PTC. The aim of our study was to test immunoreactivity of PTC for another inhibitor of proteases, alpha‐1‐antichymotrypsin (A1ACT).Methods and resultsSerial paraffin sections of nine consecutive cases of PTC were tested with anti‐A1AT and anti‐A1ACT antibodies. No immunoreactivity for A1AT and A1ACT was found in the normal thyroid tissue surrounding each tumour. In seven out of nine cases, tumour cells of PTC showed cytoplasmic immunoreactivity for A1ACT. In two cases, A1ACT was detected even in the nuclei. Immunoreactivity for A1AT was found only in three cases. Two cases of PTC showed no staining for both A1ACT and A1AT. No significant correlation of A1ACT staining was found with various prognostic indices (age of patients, histological pattern, tumour size, presence of regional lymph node metastases). The two cases showing a lack of staining for both A1ACT and A1AT showed a more aggressive clinical behaviour.ConclusionsOur preliminary study shows that A1ACT is expressed by tumour cells in a large proportion of papillary carcinomas of the thyroid gland. Its significance remains, to the best of our knowledge, still unknown. The observation of a more aggressive behaviour in the two cases characterized by the absence of immunoreactivity for both A1ACT and A1AT suggests that the presence or absence of protease inhibitors could play a role in controlling tumour progression in PTC.