Project description:The carcinogen aflatoxin is synthesized by a cluster of genes that are regulated by the transcriptional factor, AflR. Most, but not all of these genes, have a consensus binding site for AflR in their 5’ untranslated region. Because aflR resides within the biosynthetic cluster, is has been suggested that it regulates only genes within the cluster. The objective of this study was to identify those genes transcriptionally regulated by AflR and to determine if any of those genes reside outside the aflatoxin biosynthetic cluster. To address this objective, we employed a cDNA microarray of 5,002 genes from Aspergillus flavus to monitor the expression of genes in a wild type and an aflR deletion strain of A. parasiticus. Keywords = aspergillus Keywords = aflatoxin Keywords = regulation Keywords = secondary metabolism Keywords: time-course
Project description:The carcinogen aflatoxin is synthesized by a cluster of genes that are regulated by the transcriptional factor, AflR. Most, but not all of these genes, have a consensus binding site for AflR in their 5â untranslated region. Because aflR resides within the biosynthetic cluster, is has been suggested that it regulates only genes within the cluster. The objective of this study was to identify those genes transcriptionally regulated by AflR and to determine if any of those genes reside outside the aflatoxin biosynthetic cluster. To address this objective, we employed a cDNA microarray of 5,002 genes from Aspergillus flavus to monitor the expression of genes in a wild type and an aflR deletion strain of A. parasiticus. Keywords = aspergillus Keywords = aflatoxin Keywords = regulation Keywords = secondary metabolism
Project description:BACKGROUND: Secondary structure forms an important intermediate level of description of nucleic acids that encapsulates the dominating part of the folding energy, is often well conserved in evolution, and is routinely used as a basis to explain experimental findings. Based on carefully measured thermodynamic parameters, exact dynamic programming algorithms can be used to compute ground states, base pairing probabilities, as well as thermodynamic properties. RESULTS: The ViennaRNA Package has been a widely used compilation of RNA secondary structure related computer programs for nearly two decades. Major changes in the structure of the standard energy model, the Turner 2004 parameters, the pervasive use of multi-core CPUs, and an increasing number of algorithmic variants prompted a major technical overhaul of both the underlying RNAlib and the interactive user programs. New features include an expanded repertoire of tools to assess RNA-RNA interactions and restricted ensembles of structures, additional output information such as centroid structures and maximum expected accuracy structures derived from base pairing probabilities, or z-scores for locally stable secondary structures, and support for input in fasta format. Updates were implemented without compromising the computational efficiency of the core algorithms and ensuring compatibility with earlier versions. CONCLUSIONS: The ViennaRNA Package 2.0, supporting concurrent computations via OpenMP, can be downloaded from http://www.tbi.univie.ac.at/RNA.
Project description:The purpose of this study was to estimate the gap between the available and the ideal supply of human resources (physicians, nurses, and health promoters) to deliver the guaranteed package of prevention and health promotion services at urban and rural primary care facilities in Mexico.We conducted a cross-sectional observational study using a convenience sample. We selected 20 primary health facilities in urban and rural areas in 10 states of Mexico. We calculated the available and the ideal supply of human resources in these facilities using estimates of time available, used, and required to deliver health prevention and promotion services. We performed descriptive statistics and bivariate hypothesis testing using Wilcoxon and Friedman tests. Finally, we conducted a sensitivity analysis to test whether the non-normal distribution of our time variables biased estimation of available and ideal supply of human resources.The comparison between available and ideal supply for urban and rural primary health care facilities reveals a low supply of physicians. On average, primary health care facilities are lacking five physicians when they were estimated with time used and nine if they were estimated with time required (P < 0.05). No difference was observed between available and ideal supply of nurses in either urban or rural primary health care facilities. There is a shortage of health promoters in urban primary health facilities (P < 0.05).The available supply of physicians and health promoters is lower than the ideal supply to deliver the guaranteed package of prevention and health promotion services. Policies must address the level and distribution of human resources in primary health facilities.
Project description:Regulators of G protein signaling (RGS proteins) constrain G protein-coupled receptor (GPCR)-mediated and other responses throughout the body primarily, but not exclusively, through their GTPase activating (GAP) activity. Asthma is a highly prevalent condition characterized by airway hyper-responsiveness (AHR) to environmental stimuli resulting in part from amplified GPCR-mediated airway smooth muscle (ASM) contractility. Rgs2 or Rgs5 gene deletion in mice enhances AHR and ASM contraction whereas RGS4 knockout (KO) mice unexpectedly have decreased AHR due to increased production of the bronchodilator prostaglandin E2 (PGE2) by lung epithelial cells. Here we found that knockin mice harboring Rgs4 alleles encoding a point mutation (N128A) that sharply curtails RGS4 GAP activity had increased AHR, reduced airway PGE2 levels, and augmented GPCR-induced bronchial contraction compared to either RGS4 KO mice or WT controls. RGS4 interacted with the p85a subunit of PI3 kinase (PI3K) and inhibited PI3K-dependent PGE2 secretion elicited by TGFb in airway epithelial cells. Together these findings suggest that RGS4 affects asthma severity in part by regulating the airway inflammatory milieu in a G protein-independent manner.
Project description:A 50ml culture of Halobacterium NRC-1 knockout strain delta-ura3 with additional in-frame gene deletion of gap was grown to mid-log phase in a 125ml flask in rich media under varying oxygen and light conditions. Low and high light indicate growth in a painted flask versus growth in a standard clear flask under constant standard incubator illumination, respectively. Low and high oxygen indicate shaking in a stoppered flask at 100RPM agitation or shaking in a non-stoppered flask at 220RPM, respectively. Each of the four possible pairwise environemental combinations were assayed : High-oxygen/high-light, Low-oxygen/high-light, High-oxygen/low-light and Low-oxygen/low-light. RNA extractions were performed using the Stratagene Absolutely RNA Miniprep Kit and RNA quality checked with the Agilent Bioanalyzer and with Oligo Microarrays were fabricated at the Institute for Systems Biology Microarray Facility. The arrays contain 4 spots per unique 70-mer oligonucleotides for each of 2400 non-redundant genes in Halobacterium NRC-1 Labeling, hybridization and washing have been previously described (Baliga et al. 2002) with 10 μg of RNA from the sample and reference. RNA from the final time point of a replicate experiment was used as the reference. Bias in dye incorporation was accounted for by reversing the labeling dyes (dye-flip). Raw data was processed and converted into log10 ratios with lambda (λ) values determined by a maximum likelihood method.Baliga, N. S., Pan, M., Goo, Y. A., Yi, E. C., Goodlett, D. R., Dimitrov, K., Shannon, P., Aebersold, R., Ng, W. V. & Hood, L. (2002) Proc Natl Acad Sci U S A 99:14913-84. Keywords: environmental response, genetic perturbation
Project description:A 50ml culture of Halobacterium NRC-1 knockout strain delta-ura3 with additional in-frame gene deletion of gap was grown to mid-log phase in a 125ml flask in rich media under varying oxygen and light conditions. Low and high light indicate growth in a painted flask versus growth in a standard clear flask under constant standard incubator illumination, respectively. Low and high oxygen indicate shaking in a stoppered flask at 100RPM agitation or shaking in a non-stoppered flask at 220RPM, respectively. Each of the four possible pairwise environemental combinations were assayed : High-oxygen/high-light, Low-oxygen/high-light, High-oxygen/low-light and Low-oxygen/low-light. RNA extractions were performed using the Stratagene Absolutely RNA Miniprep Kit and RNA quality checked with the Agilent Bioanalyzer and with Oligo Microarrays were fabricated at the Institute for Systems Biology Microarray Facility. The arrays contain 4 spots per unique 70-mer oligonucleotides for each of 2400 non-redundant genes in Halobacterium NRC-1 Labeling, hybridization and washing have been previously described (Baliga et al. 2002) with 10 μg of RNA from the sample and reference. RNA from the final time point of a replicate experiment was used as the reference. Bias in dye incorporation was accounted for by reversing the labeling dyes (dye-flip). Raw data was processed and converted into log10 ratios with lambda (λ) values determined by a maximum likelihood method.Baliga, N. S., Pan, M., Goo, Y. A., Yi, E. C., Goodlett, D. R., Dimitrov, K., Shannon, P., Aebersold, R., Ng, W. V. & Hood, L. (2002) Proc Natl Acad Sci U S A 99:14913-84. 4 samples were analyzed in duplicate (8 total microarrays) as dye-flips.
Project description: Ribosome profiling (RiboSeq) has emerged as a powerful technique for studying the genome-wide regulation of translation in various cells. Several steps in the biological protocol have been improved, but the bioinformatics part of RiboSeq suffers from a lack of standardization, preventing the straightforward and complete reproduction of published results. Too many published studies provide insufficient detail about the bioinformatics pipeline used. The broad range of questions that can be asked with RiboSeq makes it difficult to use a single bioinformatics tool. Indeed, many scripts have been published for addressing diverse questions. Here, we propose a unique tool (for use with multiple operating systems, OS) to standardize the general steps that must be performed systematically in RiboSeq analysis, together with the statistical analysis and quality control of the sample. The data generated can then be exploited with more specific tools. We hope that this tool will help to standardize bioinformatics analyses pipelines in the field of translation.