bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcriptional variation associated with cactus host plant adaptation in Drosophila mettleri populations
Authors: Hoang Kim , Matzkin Luciano M. , Bono Jeremy M. 
Published: September 2015

AbstractAlthough the importance of host plant chemistry in plant–insect interactions is widely accepted, the genetic basis of adaptation to host plants is not well understood. Here, we investigate transcriptional changes associated with a host plant shift in Drosophila mettleri. While D. mettleri is distributed mainly throughout the Sonoran Desert where it specializes on columnar cacti (Carnegiea gigantea and Pachycereus pringleii), a population on Santa Catalina Island has shifted to chemically divergent coastal prickly pear cactus (Opuntia littoralis). We compared gene expression of larvae from the Sonoran Desert and Santa Catalina Island when reared on saguaro (C. gigantea), coastal prickly pear and laboratory food. Consistent with expectations based on the complexity and toxicity of cactus relative to laboratory food, within‐population comparisons between larvae reared on these food sources revealed transcriptional differences in detoxification and other metabolic pathways. The majority of transcriptional differences between populations on the cactus hosts were independent of the rearing environment and included a disproportionate number of genes involved in processes relevant to host plant adaptation (e.g. detoxification, central metabolism and chemosensory pathways). Comparisons of transcriptional reaction norms between the two populations revealed extensive shared plasticity that likely allowed colonization of coastal prickly pear on Santa Catalina Island. We also found that while plasticity may have facilitated subsequent adaptive divergence in gene expression between populations, the majority of genes that differed in expression on the novel host were not transcriptionally plastic in the presumed ancestral state.
Evaluation of the effects of Streptococcus mutans chaperones and protein secretion machinery components on cell surface protein biogenesis, competence, and mutacin production
Authors: Crowley P.J. , Brady L.J. 
Published: September 2015

SummaryThe respective contributions of components of the protein translocation/maturation machinery to cell surface biogenesis in Streptococcus mutans are not fully understood. Here we used a genetic approach to characterize the effects of deletion of genes encoding the ribosome‐associated chaperone RopA (Trigger Factor), the surface‐localized foldase PrsA, and the membrane‐localized chaperone insertases YidC1 and YidC2, both singly and in combination, on bacterial growth, chain length, self‐aggregation, cell surface hydrophobicity, autolysis, and antigenicity of surface proteins P1 (AgI/II, PAc), WapA, GbpC, and GtfD. The single and double deletion mutants, as well as additional mutant strains lacking components of the signal recognition particle pathway, were also evaluated for their effects on mutacin production and genetic competence.
Diurnal patterns in Scots pine stem oleoresin pressure in a boreal forest
Authors: Rissanen K. , Hölttä T. , Vanhatalo A. , Aalto J. , Nikinmaa E. , Rita H. , Bäck J. 
Published: September 2015

AbstractConiferous tree stems contain large amounts of oleoresin under positive pressure in the resin ducts. Studies in North‐American pines indicated that the stem oleoresin exudation pressure (OEP) correlates negatively with transpiration rate and soil water content. However, it is not known how the OEP changes affect the emissions of volatile vapours from the trees. We measured the OEP, xylem diameter changes indicating changes in xylem water potential and monoterpene emissions under field conditions in mature Scots pine (Pinus sylvestris L.) trees in southern Finland. Contrary to earlier reports, the diurnal OEP changes were positively correlated with temperature and transpiration rate. OEP was lowest at the top part of the stem, where water potentials were also more negative, and often closely linked to ambient temperature and stem monoterpene emissions. However, occasionally OEP was affected by sudden changes in vapour pressure deficit (VPD), indicating the importance of xylem water potential on OEP as well. We conclude that the oleoresin storage pools in tree stems are in a dynamic relationship with ambient temperature and xylem water potential, and that the canopy monoterpene emission rates may therefore be also regulated by whole tree processes and not only by the conditions prevailing in the upper canopy.
The Arabidopsis F‐box E3 ligase RIFP1 plays a negative role in abscisic acid signalling by facilitating ABA receptor RCAR3 degradation
Authors: Li Ying , Zhang Liang , Li Dekuan , Liu Zhibin , Wang Jianmei , Li Xufeng , Yang Yi 
Published: September 2015

AbstractThe phytohormone abscisic acid (ABA) plays a vital role in plant growth and development. The function of ABA is mediated by a group of newly discovered ABA receptors, named PYRABACTIN RESISTANCE 1/PYR‐LIKE/REGULATORY COMPONENTS OF ABA RECEPTORs (PYR1/PYLs/RCARs). Here, we report that an Arabidopsis thaliana F‐box protein RCAR3 INTERACTING F‐BOX PROTEIN 1 (RIFP1) interacts with ABA receptor (RCAR3) and SCF E3 ligase complex subunits Arabidopsis SKP1‐LIKE PROTEINs (ASKs) in vitro and in vivo. The rifp1 mutant plants displayed increased ABA‐mediated inhibition of seed germination and water loss of detached leaves, while the overexpression of RIFP1 in Arabidopsis led to plants being insensitive to ABA. Meanwhile, the rifp1 mutant plants showed greater tolerance to water deficit. In addition, the RCAR3 protein level was more stable in the rifp1 mutant plants than in the wild‐type plants, indicating that RIFP1 facilitates the proteasome degradation of RCAR3. Accordingly, the loss of RIFP1 increased the transcript levels of several ABA‐responsive genes. Taken together, these data indicate that RIFP1 plays a negative role in the RCAR3‐mediated ABA signalling pathway and likely functions as an adaptor subunit of the SCF ubiquitin ligase complex to regulate ABA receptor RCAR3 stability.
Temporal kinetics of the transcriptional response to carbon depletion and sucrose readdition in Arabidopsis seedlings
Authors: Cookson Sarah Jane , Yadav Umesh Prasad , Klie Sebastian , Morcuende Rosa , Usadel Björn , Lunn John Edward , Stitt Mark 
Published: September 2015

AbstractTo investigate whether the transcriptional response to carbon (C) depletion and sucrose resupply depends on the duration and severity of the C depletion, Arabidopsis seedlings were grown in liquid culture and harvested 3, 6, 12, 24, 48 and 72 h after removing sucrose from the medium and 30 min after resupplying sucrose at each time. Expression profiling revealed early transcriptional inhibition of cell wall synthesis and remodelling of signalling, followed by induction of C recycling and photosynthesis and general inhibition of growth. The temporal sequence differed from the published response to progressive exhaustion of C during a night and extended night in vegetatively growing plants. The response to sucrose readdition was conserved across the C‐depletion time course. Intriguingly, the vast majority of rapidly responding transcripts decreased rather than increased. The majority of transcripts that respond rapidly to sucrose and many transcripts that respond during C depletion also decrease after treating seedlings with the transcriptional inhibitor cordycepin A. Comparison with published responses to overexpression of otsA, AKIN10 and bZIP11 revealed that many genes that respond to C depletion, and especially sucrose resupply, respond to one or more of these C‐signalling components. Thus, multiple factors contribute to C responsiveness, including many signalling components, transcriptional regulation and transcript turnover.
Twitter and Political Campaigning
Authors: Vergeer Maurice 
Published: September 2015

AbstractThe use of Twitter by politicians, parties, and the general audience in politics, particularly during election campaigns, has become an extremely popular research field almost overnight. Even though Twitter, a medium that emerged early in 2006 – the first tweet was posted on 21 March 2006 by Jack Dorsey, co‐founder of Twitter – and elections occurring only every few years, it has already received much academic attention. The studies produced are very diverse, ranging from analyzing how politicians or citizens use Twitter, to looking at their activities and the content of political Twitter messages, to network studies of Twitter users. This review will cover many types of studies that characterize the field. The large diversity in the studies conducted on elections will be represented in this review of approaches.
Over the Hill, Under Siege: Labor Force Graying, Labor Market Pushes, and Consequences for Life Chances
Authors: Lassus Lora A. Phillips 
Published: September 2015

AbstractInterest in older workers has recently expanded due to concerns over labor force “graying.” Research and policy on aging adults' labor market participation have, thus far, framed the decision to labor as one shaped solely by the desires and capacities of older workers themselves. This perspective fails to recognize how multiple employer‐side barriers play a large role in defining – and limiting – available choices. In this review, I synthesize the multi‐disciplinary literature on employer‐side barriers to older workers' labor market participation. In particular, I identify and discuss individual‐, meso‐, and social structural‐level barriers that uniquely affect this group, noting where gaps in understanding remain. I consider older workers primarily as a whole to demonstrate how age operates as a distinct, important identity; however, I also reflect on how age overlaps with both other identities and cohort membership. Next, I briefly consider the relationship between these employer‐side barriers and aging adults' life chances, particularly in an era of austerity. Although I focus on the United States case, I also note key cross‐national similarities and differences. Finally, reflecting upon the foregoing review, I suggest that a redirection of public policy is necessary to effectively respond to this contemporary demographic shift.
Beyond the Sociology of Diagnosis
Authors: Jutel Annemarie 
Published: September 2015

AbstractThe sociology of diagnosis offers a vantage point from which to study health and illness, linking a number of other threads of sociological thought. While there has been a growing interest in diagnosis since Mildred Blaxter's suggestion for a sociological exploration in 1978 – a call echoed by Brown in 1990 – it is timely to reflect upon the way in which sociologists engage with diagnosis. Within this review essay, I first consider what it is to “be a sociology” in general terms. I then explore the implications of this for an effective sociology of diagnosis, discussing the priorities it has recently developed as well as the directions its scholars might consider. Finally, I suggest ways in which sociologists of diagnosis could broaden their approach in order to advance their understanding of health, illness, and medicine.
Metabolic Pathway Involved in 2-Methyl-6-Ethylaniline Degradation by Sphingobium sp. Strain MEA3-1 and Cloning of the Novel Flavin-Dependent Monooxygenase System
meaBA
Authors: Dong Weiliang , Chen Qiongzhen , Hou Ying , Li Shuhuan , Zhuang Kai , Huang Fei , Zhou Jie , Li Zhoukun , Wang Jue , Fu Lei , Zhang Zhengguang , Huang Yan , Wang Fei , Cui Zhongli 
Published: September 2015

ABSTRACT

2-Methyl-6-ethylaniline (MEA) is the main microbial degradation intermediate of the chloroacetanilide herbicides acetochlor and metolachlor.
Sphingobium
sp. strain MEA3-1 can utilize MEA and various alkyl-substituted aniline and phenol compounds as sole carbon and energy sources for growth. We isolated the mutant strain MEA3-1Mut, which converts MEA only to 2-methyl-6-ethyl-hydroquinone (MEHQ) and 2-methyl-6-ethyl-benzoquinone (MEBQ). MEA may be oxidized by the P450 monooxygenase system to 4-hydroxy-2-methyl-6-ethylaniline (4-OH-MEA), which can be hydrolytically spontaneously deaminated to MEBQ or MEHQ. The MEA microbial metabolic pathway was reconstituted based on the substrate spectra and identification of the intermediate metabolites in both the wild-type and mutant strains. Plasmidome sequencing indicated that both strains harbored 7 plasmids with sizes ranging from 6,108 bp to 287,745 bp. Among the 7 plasmids, 6 were identical, and pMEA02′ in strain MEA3-1Mut lost a 37,000-bp fragment compared to pMEA02 in strain MEA3-1. Two-dimensional electrophoresis (2-DE) and protein mass fingerprinting (PMF) showed that MEA3-1Mut lost the two-component flavin-dependent monooxygenase (TC-FDM) MeaBA, which was encoded by a gene in the lost fragment of pMEA02. MeaA shared 22% to 25% amino acid sequence identity with oxygenase components of some TC-FDMs, whereas MeaB showed no sequence identity with the reductase components of those TC-FDMs. Complementation with
meaBA
in MEA3-1Mut and heterologous expression in
Pseudomonas putida
strain KT2440 resulted in the production of an active MEHQ monooxygenase.
Transcriptomic Analysis of Shiga-Toxigenic Bacteriophage Carriage Reveals a Profound Regulatory Effect on Acid Resistance in Escherichia coli
Authors: Veses-Garcia Marta , Liu Xuan , Rigden Daniel J. , Kenny John G. , McCarthy Alan J. , Allison Heather E. 
Published: September 2015

ABSTRACT

Shiga-toxigenic bacteriophages are converting lambdoid phages that impart the ability to produce Shiga toxin to their hosts. Little is known about the function of most of the genes carried by these phages or the impact that lysogeny has on the
Escherichia coli
host. Here we use next-generation sequencing to compare the transcriptomes of
E. coli
strains infected with an Stx phage, before and after triggering of the bacterial SOS response that initiates the lytic cycle of the phage. We were able to discriminate between bacteriophage genes expressed in the lysogenic and lytic cycles, and we describe transcriptional changes that occur in the bacterial host as a consequence of Stx phage carriage. Having identified upregulation of the glutamic acid decarboxylase (GAD) operon, confirmed by reverse transcription-quantitative PCR (RT-qPCR), we used phenotypic assays to establish the ability of the Stx prophage to confer a greater acid resistance phenotype on the
E. coli
host. Known phage regulators were overexpressed in
E. coli
, and the acid resistance of the recombinant strains was tested. The phage-encoded transcriptional regulator CII was identified as the controller of the acid response in the lysogen. Infection of an
E. coli
O157 strain, from which integrated Stx prophages were previously removed, showed increased acid resistance following infection with a nontoxigenic phage, ϕ24
B
. In addition to demonstrating this link between Stx phage carriage and
E. coli
acid resistance, with its implications for survival postingestion, the data set provides a number of other potential insights into the impact of lambdoid phage carriage on the biology of
E. coli
.
Global Transcriptome and Mutagenic Analyses of the Acid Tolerance Response of Salmonella enterica Serovar Typhimurium
Authors: Ryan Daniel , Pati Niladri Bhusan , Ojha Urmesh K. , Padhi Chandrashekhar , Ray Shilpa , Jaiswal Sangeeta , Singh Gajinder P. , Mannala Gopala K. , Schultze Tilman , Chakraborty Trinad , Suar Mrutyunjay 
Published: September 2015

ABSTRACT

Salmonella enterica
serovar Typhimurium (
S
. Typhimurium) is one of the leading causative agents of food-borne bacterial gastroenteritis. Swift invasion through the intestinal tract and successful establishment in systemic organs are associated with the adaptability of
S
. Typhimurium to different stress environments. Low-pH stress serves as one of the first lines of defense in mammalian hosts, which
S
. Typhimurium must efficiently overcome to establish an infection. Therefore, a better understanding of the molecular mechanisms underlying the adaptability of
S
. Typhimurium to acid stress is highly relevant. In this study, we have performed a transcriptome analysis of
S
. Typhimurium under the acid tolerance response (ATR) and found a large number of genes (∼47%) to be differentially expressed (more than 1.5-fold or less than −1.5-fold;
P
< 0.01). Functional annotation revealed differentially expressed genes to be associated with regulation, metabolism, transport and binding, pathogenesis, and motility. Additionally, our knockout analysis of a subset of differentially regulated genes facilitated the identification of proteins that contribute to
S
. Typhimurium ATR and virulence. Mutants lacking genes encoding the K
+
binding and transport protein KdpA, hypothetical protein YciG, the flagellar hook cap protein FlgD, and the nitrate reductase subunit NarZ were significantly deficient in their ATRs and displayed varied
in vitro
virulence characteristics. This study offers greater insight into the transcriptome changes of
S
. Typhimurium under the ATR and provides a framework for further research on the subject.
Helicobacter pullorum Isolated from Fresh Chicken Meat: Antibiotic Resistance and Genomic Traits of an Emerging Foodborne Pathogen
Authors: Borges Vítor , Santos Andrea , Correia Cristina Belo , Saraiva Margarida , Ménard Armelle , Vieira Luís , Sampaio Daniel A. , Pinheiro Miguel , Gomes João Paulo , Oleastro Mónica 
Published: September 2015

ABSTRACT

Meat and meat products are important sources of human intestinal infections. We report the isolation of
Helicobacter pullorum
strains from chicken meat. Bacteria were isolated from 4 of the 17 analyzed fresh chicken meat samples, using a membrane filter method. MIC determination revealed that the four strains showed acquired resistance to ciprofloxacin; one was also resistant to erythromycin, and another one was resistant to tetracycline. Whole-genome sequencing of the four strains and comparative genomics revealed important genetic traits within the
H. pullorum
species, such as 18 highly polymorphic genes (including a putative new cytotoxin gene), plasmids, prophages, and a complete type VI secretion system (T6SS). The T6SS was found in three out of the four isolates, suggesting that it may play a role in
H. pullorum
pathogenicity and diversity. This study suggests that the emerging pathogen
H. pullorum
can be transmitted to humans by chicken meat consumption/contact and constitutes an important contribution toward a better knowledge of the genetic diversity within the
H. pullorum
species. In addition, some genetic traits found in the four strains provide relevant clues to how this species may promote adaptation and virulence.
Poultry Body Temperature Contributes to Invasion Control through Reduced Expression of Salmonella Pathogenicity Island 1 Genes in Salmonella enterica Serovars Typhimurium and Enteritidis
Authors: Troxell Bryan , Petri Nicholas , Daron Caitlyn , Pereira Rafaela , Mendoza Mary , Hassan Hosni M. , Koci Matthew D. 
Published: September 2015

ABSTRACT

Salmonella enterica
serovars Typhimurium (
S
. Typhimurium) and Enteritidis (
S
. Enteritidis) are foodborne pathogens, and outbreaks are often associated with poultry products. Chickens are typically asymptomatic when colonized by these serovars; however, the factors contributing to this observation are uncharacterized. Whereas symptomatic mammals have a body temperature between 37°C and 39°C, chickens have a body temperature of 41°C to 42°C. Here,
in vivo
experiments using chicks demonstrated that numbers of viable
S
. Typhimurium or
S
. Enteritidis bacteria within the liver and spleen organ sites were ≥4 orders of magnitude lower than those within the ceca. When similar doses of
S
. Typhimurium or
S
. Enteritidis were given to C3H/HeN mice, the ratio of the intestinal concentration to the liver/spleen concentration was 1:1. In the avian host, this suggested poor survival within these tissues or a reduced capacity to traverse the host epithelial layer and reach liver/spleen sites or both.
Salmonella
pathogenicity island 1 (SPI-1) promotes localization to liver/spleen tissues through invasion of the epithelial cell layer. Following
in vitro
growth at 42°C, SPI-1 genes
sipC
,
invF
, and
hilA
and the SPI-1
rtsA
activator were downregulated compared to expression at 37°C. Overexpression of the
hilA
activators
fur
,
fliZ
, and
hilD
was capable of inducing
hilA-lacZ
at 37°C but not at 42°C despite the presence of similar levels of protein at the two temperatures. In contrast, overexpression of either
hilC
or
rtsA
was capable of inducing
hilA
and
sipC
at 42°C. These data indicate that physiological parameters of the poultry host, such as body temperature, have a role in modulating expression of virulence.
Electroacupuncture Alleviates Cisplatin-Induced Nausea in Rats
Authors: Cui Yingxue , Wang Linpeng , Shi Guangxia , Liu Lu , Pei Pei , Guo Jianyou 
Published: September 2015

Objective Acupuncture has been shown to be effective for the treatment of chemotherapy-related nausea and vomiting. The aim of this study was to explore the mechanisms of action underlying the anti-emetic effect of electroacupuncture (EA). Design Forty-eight rats received saline (n=12) or 6 mg/kg cisplatin (n=36) to establish a chemotherapy-induced nausea and vomiting model. EA was performed at CV12 (n=12), bilateral PC6 (n=12), or sham points (n=12) 3 days before and 1–2 days after cisplatin administration (4–5 times in total), at 0.5–1 mA intensity and 2/15 Hz frequency for 10 min. Kaolin intake, food intake and bodyweight change were evaluated as markers of nausea and vomiting severity. Concentrations of serotonin (5-hydroxytryptamine, 5-HT) in the duodenum and c-Fos expression in the nucleus of the solitary tract (NTS) were measured using high performance liquid chromatography and immunohistochemistry, respectively. Results Cisplatin administration led to increased kaolin intake and reduced food intake and bodyweight over the following 2 days. EA at CV12 significantly reversed the cisplatin-induced change in kaolin intake (on days 1 and 2) and food intake and bodyweight (on day 1). EA at CV12 also attenuated the cisplatin-induced increase in 5-HT in the duodenum and suppressed c-Fos expression in the NTS. EA at PC6 influenced kaolin intake (on day 1 only) and c-Fos expression, but had no statistically significant effect on food intake, bodyweight or 5-HT expression. Conclusions This study demonstrated beneficial effects of EA on chemotherapy-induced nausea and vomiting in a rat model. The anti-emetic effect of EA may be mediated through inhibition of 5-HT secretion in the duodenum and activity of the NTS.