89 research outputs found
Processed data from "Chromatin information content landscapes inform transcription factor and DNA interactions"
No full textChromatin information content landscapes inform transcription factor and DNA interactions
Authors: Ricardo D’Oliveira Albanus, Yasuhiro Kyono, John Hensley, Arushi Varshney, Peter Orchard, Jacob O. Kitzman, Stephen C. J. Parker
https://doi.org/10.1101/777532
This record contains the processed data used in our manuscript. For instructions on how to use or regenerate this data, please refer to https://github.com/ParkerLab/chromatin_information.</p
Computational prediction of ribonucleic acid-based gene regulatory mechanisms in human and Tetrahymena
No full textThesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references.The diversity and profound impact of gene regulation mediated by small RNAs (sRNAs) is just beginning to come into focus. RNA interference (RNAi) pathways have been shown to mediate processes such as genomic rearrangement in ciliates and developmental timing and tissue differentiation in plants and animals. Here we present a computational study into the function of two distinct classes of sRNAs. In the first section, we examine an uncharacterized class of sRNAs isolated from the ciliate Tetrahymena thermophila, present functional comparison to known classes of sRNAs in other organisms, and note a strong and specific relationship to a novel sequence motif. In the second section, we examine the evolutionary impact of microRNAs (miRNAs), which mediate potent post-transcriptional repression on their targets. We observe that miRNAs with tissue-specific expression exert remarkable evolutionary pressure, compelling many preferentially coexpressed genes to avoid accumulating target sites. We present tissue-specific patterns of such target depletion and note strong agreement with experimentally obtained miRNA expression patterns. Conversely, we report enrichment for targeting among genes with expression patterns spatially or temporally complementary to the miRNAs', suggesting a widespread role of tissue identity maintenance for miRNA-mediated regulation.by Jacob O. Kitzman.M.Eng
Benchmarking splice variant prediction algorithms using massively parallel splicing assays
No full textAbstract Background Variants that disrupt mRNA splicing account for a sizable fraction of the pathogenic burden in many genetic disorders, but identifying splice-disruptive variants (SDVs) beyond the essential splice site dinucleotides remains difficult. Computational predictors are often discordant, compounding the challenge of variant interpretation. Because they are primarily validated using clinical variant sets heavily biased to known canonical splice site mutations, it remains unclear how well their performance generalizes. Results We benchmark eight widely used splicing effect prediction algorithms, leveraging massively parallel splicing assays (MPSAs) as a source of experimentally determined ground-truth. MPSAs simultaneously assay many variants to nominate candidate SDVs. We compare experimentally measured splicing outcomes with bioinformatic predictions for 3,616 variants in five genes. Algorithms’ concordance with MPSA measurements, and with each other, is lower for exonic than intronic variants, underscoring the difficulty of identifying missense or synonymous SDVs. Deep learning-based predictors trained on gene model annotations achieve the best overall performance at distinguishing disruptive and neutral variants, and controlling for overall call rate genome-wide, SpliceAI and Pangolin have superior sensitivity. Finally, our results highlight two practical considerations when scoring variants genome-wide: finding an optimal score cutoff, and the substantial variability introduced by differences in gene model annotation, and we suggest strategies for optimal splice effect prediction in the face of these issues. Conclusion SpliceAI and Pangolin show the best overall performance among predictors tested, however, improvements in splice effect prediction are still needed especially within exons
Nat Methods
No full textRandom mutagenesis methods only partially cover the mutational space and are constrained by DNA synthesis length limitations. Here we demonstrate programmed allelic series (PALS), a single-volume, site-directed mutagenesis approach using microarray-programmed oligonucleotides. We created libraries including nearly every missense mutation as singleton events for the yeast transcription factor Gal4 (99.9% coverage) and human tumor suppressor p53 (93.5%). PALS-based comprehensive missense mutational scans may aid structure-function studies, protein engineering, and the interpretation of variants identified by clinical sequencing.P41 GM103533/GM/NIGMS NIH HHSUnited States/DP1HG007811/DP/NCCDPHP CDC HHSUnited States/P41GM103533/GM/NIGMS NIH HHSUnited States/Howard Hughes Medical InstituteUnited States/DP1 HG007811/HG/NHGRI NIH HHSUnited States
Fully-Autonomous LabVIEW-Controlled Robot
No full textColor poster with text, photographs, graph, and images.The purpose of this project was to design and build a fleet of 5 robots that can be used in Dr. Pierson?s LabVIEW courses. The robot is equipped with National Instruments cDAQ and cRIO devices with NI Analog Input, Analog output and Digital I/O modules. Students are able to gain experience communicating and programming with both of these devices, using them to learn about the systems of this robot and to design their own self-navigation program.University of Wisconsin--Eau Claire Office of Research and Sponsored Program
Gene amplification acts as a molecular foothold to facilitate cross-species adaptation and evasion of multiple antiviral pathways
No full textCross-species spillover events are responsible for many of the pandemics in human history including COVID-19; however, the evolutionary mechanisms that enable these events are poorly understood. We have previously modeled this process using a chimeric vaccinia virus expressing the rhesus cytomegalovirus-derived PKR antagonist RhTRS1 in place of its native PKR antagonists; E3L and K3L (VACVΔEΔK+RhTRS1). Using this virus, we demonstrated that gene amplification of rhtrs1 occurred early during experimental evolution and was sufficient to fully rescue virus replication in partially resistant African green monkey (AGM) fibroblasts. Notably, this rapid gene amplification also allowed limited virus replication in otherwise completely non-permissive human fibroblasts, suggesting that gene amplification may act as a “molecular foothold” to facilitate viral adaptation to multiple species. In this study, we demonstrate that there are multiple barriers to VACVΔEΔK+RhTRS1 replication in human cells, mediated by both PKR and RNase L. We experimentally evolved three AGM-adapted virus populations in human fibroblasts. Each population adapted to human cells bimodally, via an initial 10-fold increase in replication after only two passages followed by a second 10-fold increase in replication by passage nine. Using our Illumina-based pipeline, we found that some SNPs which had evolved during the prior AGM adaptation were rapidly lost, while 13 single-base substitutions and short indels increased over time, including two SNPs unique to HFF adapted populations. Many of these changes were associated with components of the viral RNA polymerase, although no variant was shared between all three populations. Taken together, our results demonstrate that rhtrs1 amplification was sufficient to increase viral tropism after passage in an “intermediate species” and subsequently enabled the virus to adopt different, species-specific adaptive mechanisms to overcome distinct barriers to viral replication in AGM and human cells
N Engl J Med
No full textInvestigations of noninvasive prenatal screening for aneuploidy by analysis of circulating cell-free DNA (cfDNA) have shown high sensitivity and specificity in both high-risk and low-risk cohorts. However, the overall low incidence of aneuploidy limits the positive predictive value of these tests. Currently, the causes of false positive results are poorly understood. We investigated four pregnancies with discordant prenatal test results and found in two cases that maternal duplications on chromosome 18 were the likely cause of the discordant results. Modeling based on population-level copy-number variation supports the possibility that some false positive results of noninvasive prenatal screening may be attributable to large maternal copy-number variants. (Funded by the National Institutes of Health and others.).1R01MH101221/MH/NIMH NIH HHS/United StatesDP1 HG007811/HG/NHGRI NIH HHS/United StatesDP1HG007811/DP/NCCDPHP CDC HHS/United StatesK08 HD067221/HD/NICHD NIH HHS/United StatesK08HD067221/HD/NICHD NIH HHS/United StatesR01 MH101221/MH/NIMH NIH HHS/United StatesHoward Hughes Medical Institute/United State
SOX10-regulated promoter use defines isoform-specific gene expression in Schwann cells
No full textAbstract
Background
Multicellular organisms adopt various strategies to tailor gene expression to cellular contexts including the employment of multiple promoters (and the associated transcription start sites (TSSs)) at a single locus that encodes distinct gene isoforms. Schwann cells—the myelinating cells of the peripheral nervous system (PNS)—exhibit a specialized gene expression profile directed by the transcription factor SOX10, which is essential for PNS myelination. SOX10 regulates promoter elements associated with unique TSSs and gene isoforms at several target loci, implicating SOX10-mediated, isoform-specific gene expression in Schwann cell function. Here, we report on genome-wide efforts to identify SOX10-regulated promoters and TSSs in Schwann cells to prioritize genes and isoforms for further study.
Results
We performed global TSS analyses and mined previously reported ChIP-seq datasets to assess the activity of SOX10-bound promoters in three models: (i) an adult mammalian nerve; (ii) differentiating primary Schwann cells, and (iii) cultured Schwann cells with ablated SOX10 function. We explored specific characteristics of SOX10-dependent TSSs, which provides confidence in defining them as SOX10 targets. Finally, we performed functional studies to validate our findings at four previously unreported SOX10 target loci: ARPC1A, CHN2, DDR1, and GAS7. These findings suggest roles for the associated SOX10-regulated gene products in PNS myelination.
Conclusions
In sum, we provide comprehensive computational and functional assessments of SOX10-regulated TSS use in Schwann cells. The data presented in this study will stimulate functional studies on the specific mRNA and protein isoforms that SOX10 regulates, which will improve our understanding of myelination in the peripheral nerve.http://deepblue.lib.umich.edu/bitstream/2027.42/173467/1/12864_2020_Article_6963.pd
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