Conservation, diversification and expansion of C2H2 zinc finger proteins in the Arabidopsis thaliana genome

BACKGROUND: The classical C2H2 zinc finger domain is involved in a wide range of functions and can bind to DNA, RNA and proteins. The comparison of zinc finger proteins in several eukaryotes has shown that there is a lot of lineage specific diversification and expansion. Although the number of characterized plant proteins that carry the classical C2H2 zinc finger motifs is growing, a systematic classification and analysis of a plant genome zinc finger gene set is lacking. RESULTS: We found through in silico analysis 176 zinc finger proteins in Arabidopsis thaliana that hence constitute the most abundant family of putative transcriptional regulators in this plant. Only a minority of 33 A. thaliana zinc finger proteins are conserved in other eukaryotes. In contrast, the majority of these proteins (81%) are plant specific. They are derived from extensive duplication events and form expanded families. We assigned the proteins to different subgroups and families and focused specifically on the two largest and evolutionarily youngest families (A1 and C1) that are suggested to be primarily involved in transcriptional regulation. The newly defined family A1 (24 members) comprises proteins with tandemly arranged zinc finger domains. Family C1 (64 members), earlier described as the EPF-family in Petunia, comprises proteins with one isolated or two to five dispersed fingers and a mostly invariant QALGGH motif in the zinc finger helices. Based on the amino acid pattern in these helices we could describe five different signature sequences prevalent in C1 zinc finger domains. We also found a number of non-finger domains that are conserved in these families. CONCLUSIONS: Our analysis of the few evolutionarily conserved zinc finger proteins of A. thaliana suggests that most of them could be involved in ancient biological processes like RNA metabolism and chromatin-remodeling. In contrast, the majority of the unique A. thaliana zinc finger proteins are known or suggested to be involved in transcriptional regulation. They exhibit remarkable differences in the features of their zinc finger sequences and zinc finger arrangements compared to animal zinc finger proteins. The different zinc finger helix signatures we found in family C1 may have important implications for the sequence specific DNA recognition and allow inferences about the evolution of the members in this family

A novel approach to electron data background treatment in an online wide-angle spectrometer for laser-accelerated ion and electron bunches

Laser-based ion acceleration is driven by electrical fields emerging when target electrons absorb laser energy and consecutively leave the target material. A direct correlation between these electrons and the accelerated ions is thus to be expected and predicted by theoretical models. We report on a modified wide-angle spectrometer allowing the simultaneous characterization of angularly resolved energy distributions of both ions and electrons. Equipped with online pixel detectors, the RadEye1 detectors, the investigation of this correlation gets attainable on a single shot basis. In addition to first insights, we present a novel approach for reliably extracting the primary electron energy distribution from the interfering secondary radiation background. This proves vitally important for quantitative extraction of average electron energies (temperatures) and emitted total charge

An automated, 0.5Hz nano-foil target positioning system for intense laser plasma experiments

We report on a target system supporting automated positioning of nano-targets with a precision resolution of in three dimensions. It relies on a confocal distance sensor and a microscope. The system has been commissioned to position nanometer targets with 1Hz repetition rate. Integrating our prototype into the table-top ATLAS 300 TW-laser system at the Laboratory for Extreme Photonics in Garching, we demonstrate the operation of a 0.5Hz laser-driven proton source with a shot-to-shot variation of the maximum energy about 27% for a level of confidence of 0.95. The reason of laser shooting experiments operated at 0.5Hz rather than 1Hz is because the synchronization between the nano-foil target positioning system and the laser trigger needs to improve.DFG Cluster of Excellence Munich-Centre for Advanced Photonics (MAP); Centre for Advanced Laser Applications; China Scholarship [201508080084]SCI(E)ARTICLE

Phylogenetic Study of Plant Q-type C2H2 Zinc Finger Proteins and Expression Analysis of Poplar Genes in Response to Osmotic, Cold and Mechanical Stresses

Plant Q-type C2H2 zinc finger transcription factors play an important role in plant tolerance to various environmental stresses such as drought, cold, osmotic stress, wounding and mechanical loading. To carry out an improved analysis of the specific role of each member of this subfamily in response to mechanical loading in poplar, we identified 16 two-fingered Q-type C2H2-predicted proteins from the poplar Phytozome database and compared their phylogenetic relationships with 152 two-fingered Q-type C2H2 protein sequences belonging to more than 50 species isolated from the NR protein database of NCBI. Phylogenetic analyses of these Q-type C2H2 proteins sequences classified them into two groups G1 and G2, and conserved motif distributions of interest were established. These two groups differed essentially in their signatures at the C-terminus of their two QALGGH DNA-binding domains. Two additional conserved motifs, MALEAL and LVDCHY, were found only in sequences from Group G1 or from Group G2, respectively. Functional significance of these phylogenetic divergences was assessed by studying transcript accumulation of six poplar C2H2 Q-type genes in responses to abiotic stresses; but no group specificity was found in any organ. Further expression analyses focused on PtaZFP1 and PtaZFP2, the two genes strongly induced by mechanical loading in poplars. The results revealed that these two genes were regulated by several signalling molecules including hydrogen peroxide and the phytohormone jasmonate

Laser-driven x-ray and proton micro-source and application to simultaneous single-shot bi-modal radiographic imaging

Radiographic imaging with x-rays and protons is an omnipresent tool in basic research and applications in industry, material science and medical diagnostics. The information contained in both modalities can often be valuable in principle, but difficult to access simultaneously. Laser-driven solid-density plasma-sources deliver both kinds of radiation, but mostly single modalities have been explored for applications. Their potential for bi-modal radiographic imaging has never been fully realized, due to problems in generating appropriate sources and separating image modalities. Here, we report on the generation of proton and x-ray micro-sources in laser-plasma interactions of the focused Texas Petawatt laser with solid-density, micrometer-sized tungsten needles. We apply them for bi-modal radiographic imaging of biological and technological objects in a single laser shot. Thereby, advantages of laser-driven sources could be enriched beyond their small footprint by embracing their additional unique properties, including the spectral bandwidth, small source size and multi-mode emission. Here the authors show a synchronized single-shot bi-modal x-ray and proton source based on laser-generated plasma. This source can be useful for radiographic and tomographic imaging

Patient Preferences in the Medical Product Life Cycle: What do Stakeholders Think? Semi-Structured Qualitative Interviews in Europe and the USA.

Background Patient preferences (PP), which are investigated in PP studies using qualitative or quantitative methods, are a growing area of interest to the following stakeholders involved in the medical product lifecycle: academics, health technology assessment bodies,

An automated, 0.5 Hz nano-foil target positioning system for intense laser plasma experiments

We report on a target system supporting automated positioning of nano-targets with a precision resolution of in three dimensions. It relies on a confocal distance sensor and a microscope. The system has been commissioned to position nanometer targets with 1Hz repetition rate. Integrating our prototype into the table-top ATLAS 300 TW-laser system at the Laboratory for Extreme Photonics in Garching, we demonstrate the operation of a 0.5Hz laser-driven proton source with a shot-to-shot variation of the maximum energy about 27% for a level of confidence of 0.95. The reason of laser shooting experiments operated at 0.5Hz rather than 1Hz is because the synchronization between the nano-foil target positioning system and the laser trigger needs to improve.DFG Cluster of Excellence Munich-Centre for Advanced Photonics (MAP); Centre for Advanced Laser Applications; China Scholarship [201508080084]SCI(E)ARTICLE