128 research outputs found
CBM1, a Neurospora crassa genomic cosmid library in pAC3 and its use for walking on the right arm of linkage group VII
Gene cloning in Neurospora crassa is often achieved by mutant complementation. However, the cloning strategy sometimes requires the isolation of a specific genomic region (by chromosome walking) before transformation of N. crassa. This is the case, for example, if the gene to be isolated has a non-selectable phenotype. Here we specifically describe the construction of the cosmid vector, pAC3, which is designed for direct transformation of N. crassa, its utilization for the construction of a genomic library, and chromosome walking in the region of un-10 on linkage group VII
โWhite Collar 1, a central regulator of blue light response in Neurospora, is a Zinc finger proteinโ
The Neurospora crassa blind mutant white collar-1 (wc-1) is pleiotropically defective in all blue light-induced phenomena, establishing a role for the wc-1 gene product in the signal transduction pathway. We report the cloning of the wc-1 gene isolated by chromosome walking and mutant complementation. The elucidation of the wc-1 gene product provides a key piece of the blue light signal transduction puzzle. The wc-1 gene encodes a 125 kDa protein whose encoded motifs include a single class four, zinc finger DNA binding domain and a glutamine-rich putative transcription activation domain. We demonstrate that the wc-1 zinc finger domain, expressed in Escherichia coli, is able to bind specifically to the promoter of a blue light-regulated gene of Neurospora using an in vitro gel retardation assay. Furthermore, we show that wc-1 gene expression is autoregulated and is transcriptionally induced by blue light irradiation.The Neurospora crassa blind mutant white collar-1 (wc-1) is pleiotropically defective in all blue light-induced phenomena, establishing a role for the wc-1 gene product in the signal transduction pathway. We report the cloning of the wc-1 gene isolated by chromosome walking and mutant complementation. The elucidation of the wc-1 gene product provides a key piece of the blue light signal transduction puzzle. The wc-1 gene encodes a 125 kDa protein whose encoded motifs include a single class four, zinc finger DNA binding domain and a glutamine-rich putative transcription activation domain. We demonstrate that the wc-1 zinc finger domain, expressed in Escherichia coli, is able to bind specifically to the promoter of a blue light-regulated gene of Neurospora using an in vitro gel retardation assay. Furthermore, we show that wc-1 gene expression is autoregulated and is transcriptionally induced by blue light irradiation
Neurorehabilitation therapy of patients with severe stroke based on functional electrical stimulation commanded by a brain computer interface
A water-filled garment to protect astronauts during interplanetary missions tested on board the ISS
Abstract As manned spaceflights beyond low Earth orbit are in the agenda of Space Agencies, the concerns related to space radiation exposure of the crew are still without conclusive solutions. The risk of long-term detrimental health effects needs to be kept below acceptable limits, and emergency countermeasures must be planned to avoid the short-term consequences of exposure to high particle fluxes during hardly predictable solar events. Space habitat shielding cannot be the ultimate solution: the increasing complexity of future missions will require astronauts to protect themselves in low-shielded areas, e.g. during emergency operations. Personal radiation shielding is promising, particularly if using available resources for multi-functional shielding devices. In this work we report on all steps from the conception, design, manufacturing, to the final test on board the International Space Station (ISS) of the first prototype of a water-filled garment for emergency radiation shielding against solar particle events. The garment has a good shielding potential and comfort level. On-board water is used for filling and then recycled without waste. The successful outcome of this experiment represents an important breakthrough in space radiation shielding, opening to the development of similarly conceived devices and their use in interplanetary missions as the one to Mars
The white collar complex is essential for sexual reproduction but dispensable for conidiation and invasive growth in Fusarium verticillioides
Fvwc1 and Fvwc2, orthologues of the wc-1 and wc-2 genes encoding for proteins of the white collar complex (WCC) in Neurospora crassa were cloned from Fusarium verticillioides and lack-of-function wc mutants were obtained by targeted gene disruption. Photo-conidiation was found to be absent in F. verticillioides, on the contrary, the wild type strain produced less conidia under continuous illumination than in the dark. Inactivation of any of the wc genes led to total female sterility, without affecting male fertility or asexual conidiation. No loss in colonization capability/invasive growth of the wc mutants was observed, when assessed on tomato fruits. Both Fvwc1 and Fvwc2 showed constitutive expression in the wild type cultures incubated in the dark and exposure to light caused only negligible increases in their transcription. Both Fvwc1 and Fvwc2 were down-regulated in a ฮFvmat1-2-1 gene disruption mutant, lacking a functional mating type (mat1-2-1) gene, suggesting that the MAT1-2-1 product has a positive regulatory effect on the white collar genes
Asymmetries in limb darkening reanalyzed
The cause of the asymmetries in limb darkening reported by Neckel and Labs (1987) is discussed on the basis of new, stray-light-free observations, and found to be of instrumental origin.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43709/1/11207_2004_Article_BF00158296.pd
Genome-Wide Analysis of Light- and Temperature-Entrained Circadian Transcripts in Caenorhabditis elegans
Transcriptional profiling experiments identify light- and temperature-entrained circadian transcripts in C. elegans
Broadband Dielectric Spectroscopy on Human Blood
Dielectric spectra of human blood reveal a rich variety of dynamic processes.
Achieving a better characterization and understanding of these processes not
only is of academic interest but also of high relevance for medical
applications as, e.g., the determination of absorption rates of electromagnetic
radiation by the human body. The dielectric properties of human blood are
studied using broadband dielectric spectroscopy, systematically investigating
the dependence on temperature and hematocrit value. By covering a frequency
range from 1 Hz to 40 GHz, information on all the typical dispersion regions of
biological matter is obtained. We find no evidence for a low-frequency
relaxation (alpha-relaxation) caused, e.g., by counterion diffusion effects as
reported for some types of biological matter. The analysis of a strong
Maxwell-Wagner relaxation arising from the polarization of the cell membranes
in the 1-100 MHz region (beta-relaxation) allows for the test of model
predictions and the determination of various intrinsic cell properties. In the
microwave region beyond 1 GHz, the reorientational motion of water molecules in
the blood plasma leads to another relaxation feature (gamma-relaxation).
Between beta- and gamma-relaxation, significant dispersion is observed, which,
however, can be explained by a superposition of these relaxation processes and
is not due to an additional delta-relaxation often found in biological matter.
Our measurements provide dielectric data on human blood of so far unsurpassed
precision for a broad parameter range. All data are provided in electronic form
to serve as basis for the calculation of the absorption rate of electromagnetic
radiation and other medical purposes. Moreover, by investigating an
exceptionally broad frequency range, valuable new information on the dynamic
processes in blood is obtained.Comment: 17 pages, 9 figure
CHD1 Remodels Chromatin and Influences Transient DNA Methylation at the Clock Gene frequency
Circadian-regulated gene expression is predominantly controlled by a transcriptional negative feedback loop, and it is evident that chromatin modifications and chromatin remodeling are integral to this process in eukaryotes. We previously determined that multiple ATPโdependent chromatin-remodeling enzymes function at frequency (frq). In this report, we demonstrate that the Neurospora homologue of chd1 is required for normal remodeling of chromatin at frq and is required for normal frq expression and sustained rhythmicity. Surprisingly, our studies of CHD1 also revealed that DNA sequences within the frq promoter are methylated, and deletion of chd1 results in expansion of this methylated domain. DNA methylation of the frq locus is altered in strains bearing mutations in a variety of circadian clock genes, including frq, frh, wc-1, and the gene encoding the frq antisense transcript (qrf). Furthermore, frq methylation depends on the DNA methyltransferase, DIM-2. Phenotypic characterization of ฮdim-2 strains revealed an approximate WT period length and a phase advance of approximately 2 hours, indicating that methylation plays only an ancillary role in clock-regulated gene expression. This suggests that DNA methylation, like the antisense transcript, is necessary to establish proper clock phasing but does not control overt rhythmicity. These data demonstrate that the epigenetic state of clock genes is dependent on normal regulation of clock components
Simple sequence repeats in Neurospora crassa: distribution, polymorphism and evolutionary inference
<p>Abstract</p> <p>Background</p> <p>Simple sequence repeats (SSRs) have been successfully used for various genetic and evolutionary studies in eukaryotic systems. The eukaryotic model organism <it>Neurospora crassa </it>is an excellent system to study evolution and biological function of SSRs.</p> <p>Results</p> <p>We identified and characterized 2749 SSRs of 963 SSR types in the genome of <it>N. crassa</it>. The distribution of tri-nucleotide (nt) SSRs, the most common SSRs in <it>N. crassa</it>, was significantly biased in exons. We further characterized the distribution of 19 abundant SSR types (AST), which account for 71% of total SSRs in the <it>N. crassa </it>genome, using a Poisson log-linear model. We also characterized the size variation of SSRs among natural accessions using Polymorphic Index Content (PIC) and ANOVA analyses and found that there are genome-wide, chromosome-dependent and local-specific variations. Using polymorphic SSRs, we have built linkage maps from three line-cross populations.</p> <p>Conclusion</p> <p>Taking our computational, statistical and experimental data together, we conclude that 1) the distributions of the SSRs in the sequenced N. crassa genome differ systematically between chromosomes as well as between SSR types, 2) the size variation of tri-nt SSRs in exons might be an important mechanism in generating functional variation of proteins in <it>N. crassa</it>, 3) there are different levels of evolutionary forces in variation of amino acid repeats, and 4) SSRs are stable molecular markers for genetic studies in <it>N. crassa</it>.</p
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