23 research outputs found
The Clubroot Pathogen (\u3ci\u3ePlasmodiophora brassicae\u3c/i\u3e) Influences Auxin Signaling to Regulate Auxin Homeostasis in Arabidopsis
The clubroot disease, caused by the obligate biotrophic protist Plasmodiophora brassicae, affects cruciferous crops worldwide. It is characterized by root swellings as symptoms, which are dependent on the alteration of auxin and cytokinin metabolism. Here, we describe that two different classes of auxin receptors, the TIR family and the auxin binding protein 1 (ABP1) in Arabidopsis thaliana are transcriptionally upregulated upon gall formation. Mutations in the TIR family resulted in more susceptible reactions to the root pathogen. As target genes for the different pathways we have investigated the transcriptional regulation of selected transcriptional repressors (Aux/IAA) and transcription factors (ARF). As the TIR pathway controls auxin homeostasis via the upregulation of some auxin conjugate synthetases (GH3), the expression of selected GH3 genes was also investigated, showing in most cases upregulation. A double gh3 mutant showed also slightly higher susceptibility to P. brassicae infection, while all tested single mutants did not show any alteration in the clubroot phenotype. As targets for the ABP1-induced cell elongation the effect of potassium channel blockers on clubroot formation was investigated. Treatment with tetraethylammonium (TEA) resulted in less severe clubroot symptoms. This research provides evidence for the involvement of two auxin signaling pathways in Arabidopsis needed for the establishment of the root galls by P. brassicae
The Clubroot Pathogen (\u3ci\u3ePlasmodiophora brassicae\u3c/i\u3e) Influences Auxin Signaling to Regulate Auxin Homeostasis in Arabidopsis
The clubroot disease, caused by the obligate biotrophic protist Plasmodiophora brassicae, affects cruciferous crops worldwide. It is characterized by root swellings as symptoms, which are dependent on the alteration of auxin and cytokinin metabolism. Here, we describe that two different classes of auxin receptors, the TIR family and the auxin binding protein 1 (ABP1) in Arabidopsis thaliana are transcriptionally upregulated upon gall formation. Mutations in the TIR family resulted in more susceptible reactions to the root pathogen. As target genes for the different pathways we have investigated the transcriptional regulation of selected transcriptional repressors (Aux/IAA) and transcription factors (ARF). As the TIR pathway controls auxin homeostasis via the upregulation of some auxin conjugate synthetases (GH3), the expression of selected GH3 genes was also investigated, showing in most cases upregulation. A double gh3 mutant showed also slightly higher susceptibility to P. brassicae infection, while all tested single mutants did not show any alteration in the clubroot phenotype. As targets for the ABP1-induced cell elongation the effect of potassium channel blockers on clubroot formation was investigated. Treatment with tetraethylammonium (TEA) resulted in less severe clubroot symptoms. This research provides evidence for the involvement of two auxin signaling pathways in Arabidopsis needed for the establishment of the root galls by P. brassicae
Using Touchscreen Electronic Medical Record Systems to Support and Monitor National Scale-Up of Antiretroviral Therapy in Malawi
Gerry Douglas and colleagues describe the rationale and their experience with scaling up electronic health records in six antiretroviral treatment sites in Malawi
C-Reactive Protein and Genetic Variants and Cognitive Decline in Old Age: The PROSPER Study
Background: Plasma concentrations of C-reactive protein (CRP), a marker of chronic inflammation, have been associated with cognitive impairment in old age. However, it is unknown whether CRP is causally linked to cognitive decline.
Methods and Findings: Within the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) trial, with 5680 participants with a mean age of 75 years, we examined associations of CRP levels and its genetic determinants with cognitive performance and decline over 3.2 years mean follow-up. Higher plasma CRP concentrations were associated with poorer baseline performance on the Stroop test (P = 0.001) and Letter Digit Tests (P, 0.001), but not with the immediate and delayed Picture Learning Test (PLT; both P>0.5). In the prospective analyses, higher CRP concentrations associated with increased rate of decline in the immediate PLT (P = 0.016), but not in other cognitive tests (all p>0.11). Adjustment for prevalent cardiovascular risk factors and disease did not change the baseline associations nor associations with cognitive decline during follow-up. Four haplotypes of CRP were used and, compared to the common haplotype, carrierships associated strongly with levels of CRP (all P < 0.007). In comparison to strong associations of apolipoprotein E with cognitive measures, associations of CRP haplotypes with such measures were inconsistent.
Conclusion: Plasma CRP concentrations associate with cognitive performance in part through pathways independent of (risk factors for) cardiovascular disease. However, lifelong exposure to higher CRP levels does not associate with poorer cognitive performance in old age. The current data weaken the argument for a causal role of CRP in cognitive performance, but further study is warranted to draw definitive conclusions
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Metallomics Studies Of Human Blood Serum From Treated Bipolar Disorder Patients.
In the present work, metallomics studies using biomolecular (matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry, MALDI-TOF MS/MS) and elemental mass spectrometry (laser ablation inductively coupled plasma mass spectrometry, LA-ICPMS) of human blood serum samples from bipolar disorder (BD) patients compared to controls were performed. The serum samples from three different groups: control (n = 25), BD patients treated with Li (n = 15), and BD patients not treated with Li (n = 10), were pooled according to their groups and separated by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Then, in order to determine the metals bound to the protein spots and search for differences among the studied groups, the 2-D gels were analyzed by LA-ICPMS in three distinct modes: bioimaging of metals in gel sections, line scan through the protein spots, and microlocal analysis of selected protein spots. MALDI-TOF MS/MS characterized 32 serum proteins, and they were associated with the metals previously detected. When comparing control and treated BD patient groups, a differentiation in terms of metals bound to proteins was possible to observe. The main metals bound to proteins found in all groups were Na, Mg, Zn, Ca, and Fe. Mn was only detected in the control group; Co was only observed in the control and BD patients treated with Li group. K and Ti were only found in the BD patient groups, and P was only observed in control and BD patients not treated with Li drugs. This exploratory work shows that the association of LA-ICPMS with MALDI-TOF MS/MS is a powerful strategy in metallomics studies applied to determine differences in metal-containing proteins, being able to play an important role on the discovery of potential markers for BD and its treatment with Li in serum samples.825859-6
Association of <i>CRP</i> haplotypes with plasma concentrations of CRP.
<p>Data represent mean (dots) and 95% confidence interval (bars) of the difference in logarithmized CRP concentration of the different <i>CRP</i> haplotype as compared with the reference TGC haplotype.</p
Association of circulating concentrations of CRP with cognitive test performance at baseline.
<p>Mean scores on cognitive test battery were calculated at baseline using a linear regression model with tertiles of CRP as independent variable. Statistical significance of the trend was calculated using this model with CRP concentrations as continuous variable.</p><p>*Adjusted for gender, age at baseline, study site, level of education, treatment allocation (none at baseline), APOE genotype, and (if applicable) version of test used.</p>†<p>Additionally adjusted for history of hypertension, diabetes, vascular disease, myocardial infarction, stroke or transient ischemic attack, body mass index, systolic and diastolic blood pressure, smoking, LDL- and HDL-cholesterol, triglycerides.</p
Association of <i>CRP</i> haplotypes and <i>APOE</i> epsilon 2/3/4 polymorphism with cognitive function.
<p>Association with cognitive performance on the repeated cognitive test battery for <i>CRP</i> haplotypes (A) and <i>APOE</i> haplotypes (B). Data represent mean and 95% confidence of the difference in test score for each allele compared to the reference TGC allele (<i>CRP</i>) or the epsilon 3 allele (<i>APOE</i>). Cognitive test scores are oriented such that left of the dotted line always represents worse performance, whereas right of the dotted line always represents better performance.</p