667 research outputs found

    The histone deacetylase Rpd3p is required for transient changes in genomic expression in response to stress

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    BACKGROUND: Yeast responding to stress activate a large gene expression program called the Environmental Stress Response that consists of approximately 600 repressed genes and approximately 300 induced genes. Numerous factors are implicated in regulating subsets of Environmental Stress Response genes; however, a complete picture of Environmental Stress Response regulation remains unclear. We investigated the role of the histone deacetylase Rpd3p, previously linked to the upstream regions of many Environmental Stress Response genes, in producing Environmental Stress Response gene expression changes in response to stress. RESULTS: We found that the Rpd3-Large complex is required for proper expression of both induced and repressed Environmental Stress Response genes under multiple stress conditions. Cells lacking RPD3 or the Rpd3-Large subunit PHO23 had a major defect in Environmental Stress Response initiation, particularly during the transient phase of expression immediately after stress exposure. Chromatin-immunoprecipitation showed a direct role for Rpd3-Large at representative genes; however, there were different effects on nucleosome occupancy and histone deacetylation at different promoters. Computational analysis implicated regulators that may act with Rpd3p at Environmental Stress Response genes. We provide genetic and biochemical evidence that Rpd3p is required for binding and action of the stress-activated transcription factor Msn2p, although the contribution of these factors differs for different genes. CONCLUSIONS: Our results implicate Rpd3p as an important co-factor in the Environmental Stress Response regulatory network, and suggest the importance of histone modification in producing transient changes in gene expression triggered by stress

    Bile acids targeted metabolomics and medication classification data in the ADNI1 and ADNIGO/2 cohorts

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    Alzheimer’s disease (AD) is the most common cause of dementia. The mechanism of disease development and progression is not well understood, but increasing evidence suggests multifactorial etiology, with a number of genetic, environmental, and aging-related factors. There is a growing body of evidence that metabolic defects may contribute to this complex disease. To interrogate the relationship between system level metabolites and disease susceptibility and progression, the AD Metabolomics Consortium (ADMC) in partnership with AD Neuroimaging Initiative (ADNI) is creating a comprehensive biochemical database for patients in the ADNI1 cohort. We used the Biocrates Bile Acids platform to evaluate the association of metabolic levels with disease risk and progression. We detail the quantitative metabolomics data generated on the baseline samples from ADNI1 and ADNIGO/2 (370 cognitively normal, 887 mild cognitive impairment, and 305 AD). Similar to our previous reports on ADNI1, we present the tools for data quality control and initial analysis. This data descriptor represents the third in a series of comprehensive metabolomics datasets from the ADMC on the ADNI

    Author Correction: Discovery of 42 genome-wide significant loci associated with dyslexia

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    Correction to: Nature Genetics https://doi.org/10.1038/s41588-022-01192-y. Published online 20 October 2022. In the version of this article originally published, a paragraph was omitted in the Methods section, reading “Genomic control. Top SNPs are reported from the more conservative GWAS results adjusted for genomic control (Fig. 1, Extended Data Figs. 1–4, and Supplementary Tables 1, 2, 9 and 10), whereas downstream analyses (including gene-set analysis, enrichment and heritability partitioning, genetic correlations, polygenic prediction, candidate gene replication) are based on GWAS results without genomic control.” The paragraph has now been included in the HTML and PDF versions of the article

    The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

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    The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr

    Incipient Balancing Selection through Adaptive Loss of Aquaporins in Natural Saccharomyces cerevisiae Populations

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    A major goal in evolutionary biology is to understand how adaptive evolution has influenced natural variation, but identifying loci subject to positive selection has been a challenge. Here we present the adaptive loss of a pair of paralogous genes in specific Saccharomyces cerevisiae subpopulations. We mapped natural variation in freeze-thaw tolerance to two water transporters, AQY1 and AQY2, previously implicated in freeze-thaw survival. However, whereas freeze-thaw–tolerant strains harbor functional aquaporin genes, the set of sensitive strains lost aquaporin function at least 6 independent times. Several genomic signatures at AQY1 and/or AQY2 reveal low variation surrounding these loci within strains of the same haplotype, but high variation between strain groups. This is consistent with recent adaptive loss of aquaporins in subgroups of strains, leading to incipient balancing selection. We show that, although aquaporins are critical for surviving freeze-thaw stress, loss of both genes provides a major fitness advantage on high-sugar substrates common to many strains' natural niche. Strikingly, strains with non-functional alleles have also lost the ancestral requirement for aquaporins during spore formation. Thus, the antagonistic effect of aquaporin function—providing an advantage in freeze-thaw tolerance but a fitness defect for growth in high-sugar environments—contributes to the maintenance of both functional and nonfunctional alleles in S. cerevisiae. This work also shows that gene loss through multiple missense and nonsense mutations, hallmarks of pseudogenization presumed to emerge after loss of constraint, can arise through positive selection

    Detecting and Characterizing Mg II absorption in DESI Survey Validation Quasar Spectra

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    In this paper we will present findings on the detection of Magnesium II (MgII, lambda = 2796 {\AA}, 2803 {\AA}) absorption systems observed in data from the Early Data Release (EDR) of the Dark Energy Spectroscopic Instrument (DESI). DESI is projected to obtain spectroscopy of approximately 3 million quasars (QSOs), of which over 99% are anticipated to be found at redshifts greater than z < 0.3, such that DESI would be able to observe an associated or intervening Mg II absorber illuminated by the background QSO. We have developed an autonomous supplementary spectral pipeline that detects such systems through an initial line-fitting process and then confirms line properties using a Markov Chain Monte Carlo (MCMC) sampler. Based upon both a visual inspection and the reanalysis of coadded observations, we estimate this sample of absorption systems to have a completeness of 82.56% and purity of 99.08%. As the spectra in which Mg II systems are detected are the result of coadding multiple observations, we can determine the sensitivity, and therefore completeness, of the sample by searching for known Mg II systems in coadded data with fewer observations (and therefore lower signal-to-noise). From a parent catalog containing 83,207 quasars, we detect a total of 23,921 Mg II absorption systems following a series of quality cuts. Extrapolating from this occurrence rate of 28.75% implies a catalog at the completion of the five-year DESI survey that contains over eight hundred thousand Mg II absorbers. The cataloging of these systems will enable significant further research as they carry information regarding circumgalactic medium (CGM) environments, the distribution of intervening galaxies, and the growth of metallicity across the redshift range 0.3 < z < 2.5.Comment: 12 pages, 7 figure
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