bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immune function and parasite resistance in male and polymorphic female Coenagrion puella
Authors: Joop Gerrit , Mitschke Andreas , Rolff Jens , Siva-Jothy Michael T 
Published: March 2006

Abstract

Background
Colour polymorphisms are widespread and one of the prime examples is the colour polymorphism in female coenagrionid damselflies: one female morph resembles the male colour (andromorph) while one, or more, female morphs are described as typically female (gynomorph). However, the selective pressures leading to the evolution and maintenance of this polymorphism are not clear. Here, based on the hypothesis that coloration and especially black patterning can be related to resistance against pathogens, we investigated the differences in immune function and parasite resistance between the different female morphs and males.

Results
Our studies of immune function revealed no differences in immune function between the female morphs but between the sexes in adult damselflies. In an experimental infection females infected shortly after emergence showed a higher resistance against a fungal pathogen than males, however female morphs did not differ in resistance. In a field sample of adult damselflies we did not find differences in infection rates with watermites and gregarines.

Conclusion
With respect to resistance and immune function 'andromorph' blue females of Coenagrion puella do not resemble the males. Therefore the colour polymorphism in coenagrionid damselflies is unlikely to be maintained by differences in immunity.
Search for genetic variants in the p66Shc longevity gene by PCR-single strand conformational polymorphism in patients with early-onset cardiovascular disease
Authors: Sentinelli Federica , Romeo Stefano , Barbetti Fabrizio , Berni Andrea , Filippi Emanuela , Fanelli Marzia , Fallarino Mara , Baroni Marco G 
Published: March 2006

Abstract

Background
Among the possible candidate genes for atherosclerosis experimental data point towards the longevity gene p66Shc. The p66Shc gene determines an increase of intracellular reactive oxygen species (ROS), affecting the rate of oxidative damage to nucleic acids. Knock-out p66Shc-/- mice show reduction of systemic oxidative stress, as well as of plasma LDL oxidation, and reduced atherogenic lesions. Thus, p66Shc may play a pivotal role in controlling oxidative stress and vascular dysfunction in vivo.

Methods
We searched for sequence variations in the p66Shc specific region of the Shc gene and its upstream promoter by PCR-SSCP in a selected group of early onset coronary artery disease (CAD) subjects (n. 78, mean age 48.5 ± 6 years) and in 93 long-living control subjects (mean age 89 ± 6 years).

Results
The analysis revealed two variant bands. Sequencing of these variants showed two SNPs: -354T>C in the regulatory region of p66Shc locus and 92C>T in the p66 specific region (CH2). Both these variants have never been described before. The first substitution partially modifies the binding consensus sequence of the Sp1 transcription factor, and was detected only in two heterozygous carriers (1 CAD subjects and 1 control subject). The 92C>T substitution in the CH2 region consists in an amino acid substitution at codon 31 (proline to leucine, P31L), and was detected in heterozygous status only in one CAD subject. No subjects homozygous for the two newly described SNPs were found.

Conclusion
Only two sequence variations in the p66Shc gene were observed in a total of 171 subjects, and only in heterozygotes. Our observations, in accordance to other studies, suggest that important variations in the p66Shc gene may be extremely rare and probably this gene is not involved in the genetic susceptibility to CAD.
QTL for microstructural and biophysical muscle properties and body composition in pigs
Authors: Wimmers Klaus , Fiedler Ilse , Hardge Torsten , Murani Eduard , Schellander Karl , Ponsuksili Siriluck 
Published: March 2006

Abstract

Background
The proportion of muscle fibre types and their size affect muscularity as well as functional properties of the musculature and meat quality. We aimed to identify QTL for microstructural muscle properties including muscle fibre size, their numbers and fibre type proportions as well as biophysical parameters of meat quality and traits related to body composition, i.e. pH, conductivity, area of M. longissimus dorsi and lean meat content. A QTL scan was conducted in a porcine experimental population that is based on Duroc and Berlin Miniature Pig.

Results
Least square regression interval mapping revealed five significant and 42 suggestive QTL for traits related to muscle fibre composition under the line-cross model as well as eight significant and 40 suggestive QTL under the half-sib model. For traits related to body composition and biophysical parameters of meat quality five and twelve significant plus nine and 22 suggestive QTL were found under the line-cross and half-sib model, respectively. Regions with either significant QTL for muscle fibre traits or significant QTL for meat quality and muscularity or both were detected on SSC1, 2, 3, 4, 5, 13, 14, 15, and 16. QTL for microstructural properties explained a larger proportion of variance than did QTL for meat quality and body composition.

Conclusion
Microstructural properties of pig muscle and meat quality are governed by genetic variation at many loci distributed throughout the genome. QTL analysis under both, the line-cross and half-sib model, allows detecting QTL in case of fixation or segregation of the QTL alleles among the founder populations and thus provide comprehensive insight into the genetic variation of the traits under investigation. Genomic regions affecting complex traits of muscularity and meat quality as well as microstructural properties might point to QTL that in first instance affect muscle fibre traits and by this in second instance meat quality. Disentangling complex traits in their constituent phenotypes might facilitate the identification of QTL and the elucidation of the pleiotropic nature of QTL effects.
A dehydration-inducible gene in the truffle Tuber borchii identifies a novel group of dehydrins
Authors: Abba' Simona , Ghignone Stefano , Bonfante Paola 
Published: March 2006

Abstract

Background
The expressed sequence tag M6G10 was originally isolated from a screening for differentially expressed transcripts during the reproductive stage of the white truffle Tuber borchii. mRNA levels for M6G10 increased dramatically during fruiting body maturation compared to the vegetative mycelial stage.

Results
Bioinformatics tools, phylogenetic analysis and expression studies were used to support the hypothesis that this sequence, named TbDHN1, is the first dehydrin (DHN)-like coding gene isolated in fungi. Homologs of this gene, all defined as "coding for hypothetical proteins" in public databases, were exclusively found in ascomycetous fungi and in plants. Although complete (or almost complete) fungal genomes and EST collections of some Basidiomycota and Glomeromycota are already available, DHN-like proteins appear to be represented only in Ascomycota. A new and previously uncharacterized conserved signature pattern was identified and proposed to Uniprot database as the main distinguishing feature of this new group of DHNs. Expression studies provide experimental evidence of a transcript induction of TbDHN1 during cellular dehydration.

Conclusion
Expression pattern and sequence similarities to known plant DHNs indicate that TbDHN1 is the first characterized DHN-like protein in fungi. The high similarity of TbDHN1 with homolog coding sequences implies the existence of a novel fungal/plant group of LEA Class II proteins characterized by a previously undescribed signature pattern.
Comparative genomics profiling of clinical isolates of Aeromonas salmonicida using DNA microarrays
Authors: Nash John HE , Findlay Wendy A , Luebbert Christian C , Mykytczuk Oksana L , Foote Simon J , Taboada Eduardo N , Carrillo Catherine D , Boyd Jessica M , Colquhoun Duncan J , Reith Michael E , Brown Laura L 
Published: March 2006

Abstract

Background

Aeromonas salmonicida has been isolated from numerous fish species and shows wide variation in virulence and pathogenicity. As part of a larger research program to identify virulence genes and candidates for vaccine development, a DNA microarray was constructed using a subset of 2024 genes from the draft genome sequence of A. salmonicida subsp. salmonicida strain A449. The microarray included genes encoding known virulence-associated factors in A. salmonicida and homologs of virulence genes of other pathogens. We used microarray-based comparative genomic hybridizations (M-CGH) to compare selected A. salmonicida sub-species and other Aeromonas species from different hosts and geographic locations.

Results
Results showed variable carriage of virulence-associated genes and generally increased variation in gene content across sub-species and species boundaries. The greatest variation was observed among genes associated with plasmids and transposons. There was little correlation between geographic region and degree of variation for all isolates tested.

Conclusion
We have used the M-CGH technique to identify subsets of conserved genes from amongst this set of A. salmonicida virulence genes for further investigation as potential vaccine candidates. Unlike other bacterial characterization methods that use a small number of gene or DNA-based functions, M-CGH examines thousands of genes and/or whole genomes and thus is a more comprehensive analytical tool for veterinary or even human health research.
Duplication and relocation of the functional DPY19L2 gene within low copy repeats
Authors: Carson Andrew R , Cheung Joseph , Scherer Stephen W 
Published: March 2006

Abstract

Background
Low copy repeats (LCRs) are thought to play an important role in recent gene evolution, especially when they facilitate gene duplications. Duplicate genes are fundamental to adaptive evolution, providing substrates for the development of new or shared gene functions. Moreover, silencing of duplicate genes can have an indirect effect on adaptive evolution by causing genomic relocation of functional genes. These changes are theorized to have been a major factor in speciation.

Results
Here we present a novel example showing functional gene relocation within a LCR. We characterize the genomic structure and gene content of eight related LCRs on human Chromosomes 7 and 12. Two members of a novel transmembrane gene family, DPY19L, were identified in these regions, along with six transcribed pseudogenes. One of these genes, DPY19L2, is found on Chromosome 12 and is not syntenic with its mouse orthologue. Instead, the human locus syntenic to mouse Dpy19l2 contains a pseudogene, DPY19L2P1. This indicates that the ancestral copy of this gene has been silenced, while the descendant copy has remained active. Thus, the functional copy of this gene has been relocated to a new genomic locus. We then describe the expansion and evolution of the DPY19L gene family from a single gene found in invertebrate animals. Ancient duplications have led to multiple homologues in different lineages, with three in fish, frogs and birds and four in mammals.

Conclusion
Our results show that the DPY19L family has expanded throughout the vertebrate lineage and has undergone recent primate-specific evolution within LCRs.
Molecular approaches to identify and differentiate Bacillus anthracis from phenotypically similar Bacillus species isolates
Authors: Marston Chung K , Gee Jay E , Popovic Tanja , Hoffmaster Alex R 
Published: March 2006

Abstract

Background

Bacillus anthracis and Bacillus cereus can usually be distinguished by standard microbiological methods (e.g., motility, hemolysis, penicillin susceptibility and susceptibility to gamma phage) and PCR. However, we have identified 23 Bacillus spp. isolates that gave discrepant results when assayed by standard microbiological methods and PCR. We used multiple-locus variable-number tandem repeat analysis (MLVA), multiple-locus sequence typing (MLST), and phenotypic analysis to characterize these isolates, determine if they cluster phylogenetically and establish whether standard microbiological identification or PCR were associated with false positive/negative results.

Results
Six isolates were LRN real-time PCR-positive but resistant to gamma phage; MLVA data supported the identification of these isolates as gamma phage-resistant B. anthracis. Seventeen isolates were LRN real-time PCR-negative but susceptible to gamma phage lysis; these isolates appear to be a group of unusual gamma phage-susceptible B. cereus isolates that are closely related to each other and to B. anthracis. All six B. anthracis MLVA chromosomal loci were amplified from one unusual gamma phage-susceptible, motile, B. cereus isolate (although the amplicons were atypical sizes), and when analyzed phylogenetically, clustered with B. anthracis by MLST.

Conclusion
MLVA and MLST aided in the identification of these isolates when standard microbiological methods and PCR could not definitely identify or rule out B. anthracis. This study emphasized the need to perform multiple tests when attempting to identify B. anthracis since relying on a single assay remains problematic due to the diverse nature of bacteria.
The Subviral RNA Database: a toolbox for viroids, the hepatitis delta virus and satellite RNAs research
Authors: Rocheleau Lynda , Pelchat Martin 
Published: March 2006

Abstract

Background
Viroids, satellite RNAs, satellites viruses and the human hepatitis delta virus form the 'brotherhood' of the smallest known infectious RNA agents, known as the subviral RNAs. For most of these species, it is generally accepted that characteristics such as cell movement, replication, host specificity and pathogenicity are encoded in their RNA sequences and their resulting RNA structures. Although many sequences are indexed in publicly available databases, these sequence annotation databases do not provide the advanced searches and data manipulation capability for identifying and characterizing subviral RNA motifs.

Description
The Subviral RNA database is a web-based environment that facilitates the research and analysis of viroids, satellite RNAs, satellites viruses, the human hepatitis delta virus, and related RNA sequences. It integrates a large number of Subviral RNA sequences, their respective RNA motifs, analysis tools, related publication links and additional pertinent information (ex. links, conferences, announcements), allowing users to efficiently retrieve and analyze relevant information about these small RNA agents.

Conclusion
With its design, the Subviral RNA Database could be considered as a fundamental building block for the study of these related RNAs. It is freely available via a web browser at the URL: http://subviral.med.uottawa.ca.
Cyclic nucleotide specific phosphodiesterases of Leishmania major
Authors: Johner Andrea , Kunz Stefan , Linder Markus , Shakur Yasmin , Seebeck Thomas 
Published: March 2006

Abstract

Background

Leishmania represent a complex of important human pathogens that belong to the systematic order of the kinetoplastida. They are transmitted between their human and mammalian hosts by different bloodsucking sandfly vectors. In their hosts, the Leishmania undergo several differentiation steps, and their coordination and optimization crucially depend on numerous interactions between the parasites and the physiological environment presented by the fly and human hosts. Little is still known about the signalling networks involved in these functions. In an attempt to better understand the role of cyclic nucleotide signalling in Leishmania differentiation and host-parasite interaction, we here present an initial study on the cyclic nucleotide-specific phosphodiesterases of Leishmania major.

Results
This paper presents the identification of three class I cyclic-nucleotide-specific phosphodiesterases (PDEs) from L. major, PDEs whose catalytic domains exhibit considerable sequence conservation with, among other, all eleven human PDE families. In contrast to other protozoa such as Dictyostelium, or fungi such as Saccharomyces cerevisiae, Candida ssp or Neurospora, no genes for class II PDEs were found in the Leishmania genomes. LmjPDEA contains a class I catalytic domain at the C-terminus of the polypeptide, with no other discernible functional domains elsewhere. LmjPDEB1 and LmjPDEB2 are coded for by closely related, tandemly linked genes on chromosome 15. Both PDEs contain two GAF domains in their N-terminal region, and their almost identical catalytic domains are located at the C-terminus of the polypeptide. LmjPDEA, LmjPDEB1 and LmjPDEB2 were further characterized by functional complementation in a PDE-deficient S. cerevisiae strain. All three enzymes conferred complementation, demonstrating that all three can hydrolyze cAMP. Recombinant LmjPDEB1 and LmjPDEB2 were shown to be cAMP-specific, with Km values in the low micromolar range. Several PDE inhibitors were found to be active against these PDEs in vitro, and to inhibit cell proliferation.

Conclusion
The genome of L. major contains only PDE genes that are predicted to code for class I PDEs, and none for class II PDEs. This is more similar to what is found in higher eukaryotes than it is to the situation in Dictyostelium or the fungi that concomitantly express class I and class II PDEs. Functional complementation demonstrated that LmjPDEA, LmjPDEB1 and LmjPDEB2 are capable of hydrolyzing cAMP. In vitro studies with recombinant LmjPDEB1 and LmjPDEB2 confirmed this, and they demonstrated that both are completely cAMP-specific. Both enzymes are inhibited by several commercially available PDE inhibitors. The observation that these inhibitors also interfere with cell growth in culture indicates that inhibition of the PDEs is fatal for the cell, suggesting an important role of cAMP signalling for the maintenance of cellular integrity and proliferation.
The Escherichia coli BarA-UvrY two-component system is a virulence determinant in the urinary tract
Authors: Tomenius Henrik , Pernestig Anna-Karin , Jonas Kristina , Georgellis Dimitris , Möllby Roland , Normark Staffan , Melefors Öjar 
Published: March 2006

Abstract

Background
The Salmonella enterica BarA-SirA, the Erwinia carotovora ExpS-ExpA, the Vibrio cholerae BarA-VarA and the Pseudomonas spp GacS-GacA all belong to the same orthologous family of two-component systems as the Escherichia coli BarA-UvrY. In the first four species it has been demonstrated that disruption of this two-component system leads to a clear reduction in virulence of the bacteria. Our aim was to determine if the Escherichia coli BarA-UvrY two-component system is connected with virulence using a monkey cystitis model.

Results
Cystitis was generated in Macaque fascularis monkeys by infecting the bladder with a 1:1 mixture of the uropathogenic Escherichia coli isolate DS17 and a derivative where the uvrY gene had been disrupted with a kanamycin resistance gene. Urine was collected through bladder punctuation at subsequent time intervals and the relative amount of uvrY mutant was determined. This showed that inactivation of the UvrY response regulator leads to a reduced fitness. In similar competitions in culture flasks with Luria Broth (LB) the uvrY mutant rather had a higher fitness than the wild type. When the competitions were done in flasks with human urine the uvrY mutant initially had a lower fitness. This was followed by a fluctuation in the level of mutant in the long-term culture, with a pattern that was specific for the individual urines that were tested. Addition of LB to the different urine competition cultures however clearly led to a consistently higher fitness of the uvrY mutant.

Conclusion
This paper demonstrates that the BarA-UvrY two-component system is a determinant for virulence in a monkey cystitis model. The observed competition profiles strengthen our previous hypothesis that disruption of the BarA-UvrY two-component system impairs the ability of the bacteria to switch between different carbon sources. The urine in the bladder contains several different carbon sources and its composition changes over time. Inability to efficiently switch between the carbon sources may thus provide an explanation to the reduced fitness of the uvrY mutant in the cystitis model.
Role of the ERK pathway in psychostimulant-induced locomotor sensitization
Authors: Valjent Emmanuel , Corvol Jean-Christophe , Trzaskos James M , Girault Jean-Antoine , Hervé Denis 
Published: March 2006

Abstract

Background
Repeated exposure to psychostimulants results in a progressive and long-lasting facilitation of the locomotor response that is thought to have implications for addiction. Psychostimulants and other drugs of abuse activate in specific brain areas extracellular signal-regulated kinase (ERK), an essential component of a signaling pathway involved in synaptic plasticity and long-term effects of drugs of abuse. Here we have investigated the role of ERK activation in the behavioral sensitization induced by repeated administration of psychostimulants in mice, using SL327, a brain-penetrating selective inhibitor of MAP-kinase/ERK kinase (MEK), the enzyme that selectively activates ERK.

Results
A dose of SL327 (30 mg/kg) that reduced the number of activated ERK-positive neurons by 62 to 89% in various brain areas, had virtually no effect on the spontaneous locomotor activity or the acute hyperlocomotion induced by cocaine or D-amphetamine. Pre-treatment with SL327 (30 mg/kg) prior to each drug administration prevented the locomotor sensitization induced by repeated injections of D-amphetamine or cocaine. The SL327 pre-treatment abolished also conditioned locomotor response of mice placed in the context previously paired with cocaine or D-amphetamine. In contrast, SL327 did not alter the expression of sensitized response to D-amphetamine or cocaine.

Conclusion
Altogether these results show that ERK has a minor contribution to the acute locomotor effects of psychostimulants or to the expression of sensitized responses, whereas it is crucial for the acquisition of locomotor sensitization and psychostimulant-conditioned locomotor response. This study supports the important role of the ERK pathway in long-lasting behavioral alterations induced by drugs of abuse.