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Ul Haq I, Zhang KX, Gou Y, Hajjar D, Makki AA, Alkherb WAH, Ali H, Liu C. Transcriptomic and biochemical insights into fall armyworm ( Spodoptera frugiperda) responses on silicon-treated maize. PeerJ 2024; 12:e16859. [PMID: 38410805 PMCID: PMC10896081 DOI: 10.7717/peerj.16859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 01/09/2024] [Indexed: 02/28/2024] Open
Abstract
Background The fall armyworm, Spodoptera frugiperda, is an agricultural pest of significant economic concern globally, known for its adaptability, pesticide resistance, and damage to key crops such as maize. Conventional chemical pesticides pose challenges, including the development of resistance and environmental pollution. The study aims to investigate an alternative solution: the application of soluble silicon (Si) sources to enhance plant resistance against the fall armyworm. Methods Silicon dioxide (SiO2) and potassium silicate (K2SiO3) were applied to maize plants via foliar spray. Transcriptomic and biochemical analyses were performed to study the gene expression changes in the fall armyworm feeding on Si-treated maize. Results Results indicated a significant impact on gene expression, with a large number of differentially expressed genes (DEGs) identified in both SiO2 and K2SiO3 treatments. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified critical DEGs involved in specific pathways, including amino acid, carbohydrate, lipid, energy, xenobiotics metabolisms, signal transduction, and posttranslational modification, significantly altered at both Si sources. Biochemical analyses further revealed that Si treatments inhibited several enzyme activities (glutamate dehydrogenase, trehalase, glucose-6-phosphate dehydrogenase, chitinase, juvenile hormone esterase, and cyclooxygenase while simultaneously inducing others (total protein, lipopolysaccharide, fatty acid synthase, ATPase, and cytochrome P450), thus suggesting a toxic effect on the fall armyworm. In conclusion, Si applications on maize influence the gene expression and biochemical activities of the fall armyworm, potentially offering a sustainable pest management strategy.
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Affiliation(s)
- Inzamam Ul Haq
- College of Plant Protection, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Ke-Xin Zhang
- College of Plant Protection, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Yuping Gou
- College of Plant Protection, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Dina Hajjar
- College of Science, Department of Biochemistry, University of Jeddah, Jeddah, Saudi Arabia
| | - Arwa A Makki
- College of Science, Department of Biochemistry, University of Jeddah, Jeddah, Saudi Arabia
| | - Wafa A H Alkherb
- Department of Biology, College of Science, Qassim University, Buraidah, Saudi Arabia
| | - Habib Ali
- Department of Agricultural Engineering, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan, Pakistan
| | - Changzhong Liu
- College of Plant Protection, Gansu Agricultural University, Lanzhou, Gansu, China
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2
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Hunter S, Hendrix J, Freeman J, Dowell RD, Allen MA. Transcription dosage compensation does not occur in Down syndrome. BMC Biol 2023; 21:228. [PMID: 37946204 PMCID: PMC10636926 DOI: 10.1186/s12915-023-01700-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 09/12/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND The increase in DNA copy number in Down syndrome (DS; caused by trisomy 21) has led to the DNA dosage hypothesis, which posits that the level of gene expression is proportional to the gene's DNA copy number. Yet many reports have suggested that a proportion of chromosome 21 genes are dosage compensated back towards typical expression levels (1.0×). In contrast, other reports suggest that dosage compensation is not a common mechanism of gene regulation in trisomy 21, providing support to the DNA dosage hypothesis. RESULTS In our work, we use both simulated and real data to dissect the elements of differential expression analysis that can lead to the appearance of dosage compensation, even when compensation is demonstrably absent. Using lymphoblastoid cell lines derived from a family with an individual with Down syndrome, we demonstrate that dosage compensation is nearly absent at both nascent transcription (GRO-seq) and steady-state RNA (RNA-seq) levels. Furthermore, we link the limited apparent dosage compensation to expected allelic variation in transcription levels. CONCLUSIONS Transcription dosage compensation does not occur in Down syndrome. Simulated data containing no dosage compensation can appear to have dosage compensation when analyzed via standard methods. Moreover, some chromosome 21 genes that appear to be dosage compensated are consistent with allele specific expression.
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Affiliation(s)
- Samuel Hunter
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, 80301, USA
| | - Jo Hendrix
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA
- Computational Bioscience, The University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Center for Genes, Environment and Health, National Jewish Health, Denver, CO, USA
| | - Justin Freeman
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA
| | - Robin D Dowell
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, 80301, USA
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA
- Linda Crnic Institute for Down Syndrome, 80045, Aurora, USA
- Crnic Boulder Branch, BioFrontiers, Boulder, 80309, USA
| | - Mary A Allen
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA.
- Linda Crnic Institute for Down Syndrome, 80045, Aurora, USA.
- Crnic Boulder Branch, BioFrontiers, Boulder, 80309, USA.
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3
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Jackson R, Rajadhyaksha EV, Loeffler RS, Flores CE, Van Doorslaer K. Characterization of 3D organotypic epithelial tissues reveals tonsil-specific differences in tonic interferon signaling. PLoS One 2023; 18:e0292368. [PMID: 37792852 PMCID: PMC10550192 DOI: 10.1371/journal.pone.0292368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/18/2023] [Indexed: 10/06/2023] Open
Abstract
Three-dimensional (3D) culturing techniques can recapitulate the stratified nature of multicellular epithelial tissues. Organotypic 3D epithelial tissue culture methods have several applications, including the study of tissue development and function, drug discovery and toxicity testing, host-pathogen interactions, and the development of tissue-engineered constructs for use in regenerative medicine. We grew 3D organotypic epithelial tissues from foreskin, cervix, and tonsil-derived primary cells and characterized the transcriptome of these in vitro tissue equivalents. Using the same 3D culturing method, all three tissues yielded stratified squamous epithelium, validated histologically using basal and superficial epithelial cell markers. The goal of this study was to use RNA-seq to compare gene expression patterns in these three types of epithelial tissues to gain a better understanding of the molecular mechanisms underlying their function and identify potential therapeutic targets for various diseases. Functional profiling by over-representation and gene set enrichment analysis revealed tissue-specific differences: i.e., cutaneous homeostasis and lipid metabolism in foreskin, extracellular matrix remodeling in cervix, and baseline innate immune differences in tonsil. Specifically, tonsillar epithelia may play an active role in shaping the immune microenvironment of the tonsil balancing inflammation and immune responses in the face of constant exposure to microbial insults. Overall, these data serve as a resource, with gene sets made available for the research community to explore, and as a foundation for understanding the epithelial heterogeneity and how it may impact their in vitro use. An online resource is available to investigate these data (https://viz.datascience.arizona.edu/3DEpiEx/).
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Affiliation(s)
- Robert Jackson
- School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | - Esha V. Rajadhyaksha
- College of Medicine and College of Science, University of Arizona, Tucson, Arizona, United States of America
| | - Reid S. Loeffler
- Biosystems Engineering, College of Agriculture and Life Sciences, College of Engineering, University of Arizona, Tucson, Arizona, United States of America
| | - Caitlyn E. Flores
- School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, Arizona, United States of America
| | - Koenraad Van Doorslaer
- School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, Cancer Biology Graduate Interdisciplinary Program, Genetics Graduate Interdisciplinary Program, and University of Arizona Cancer Center, University of Arizona, Tucson, Arizona, United States of America
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4
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Hunter S, Dowell RD, Hendrix J, Freeman J, Allen MA. Transcription dosage compensation does not occur in Down syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.543933. [PMID: 37333218 PMCID: PMC10274774 DOI: 10.1101/2023.06.07.543933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Trisomy 21, also known as Down syndrome, describes the genetic condition of having an extra copy of chromosome 21. The increase in DNA copy number has led to the "DNA dosage hypothesis", which claims that the level of gene transcription is proportional to the gene's DNA copy number. Yet many reports have suggested that a proportion of chromosome 21 genes are dosage compensated back towards typical expression levels (1.0x). In contrast, other reports suggest that dosage compensation is not a common mechanism of gene regulation in Trisomy 21, providing support to the DNA dosage hypothesis. Results In our work, we use both simulated and real data to dissect the elements of differential expression analysis that can lead to the appearance of dosage compensation even when compensation is demonstrably absent. Using lymphoblastoid cell lines derived from a family of an individual with Down syndrome, we demonstrate that dosage compensation is nearly absent at both nascent transcription (GRO-seq) and steady-state RNA (RNA-seq) levels. Conclusions Transcriptional dosage compensation does not occur in Down syndrome. Simulated data containing no dosage compensation can appear to have dosage compensation when analyzed via standard methods. Moreover, some chromosome 21 genes that appear to be dosage compensated are consistent with allele specific expression.
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5
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Le Priol C, Azencott CA, Gidrol X. Detection of genes with differential expression dispersion unravels the role of autophagy in cancer progression. PLoS Comput Biol 2023; 19:e1010342. [PMID: 36893104 PMCID: PMC9997931 DOI: 10.1371/journal.pcbi.1010342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 02/09/2023] [Indexed: 03/10/2023] Open
Abstract
The majority of gene expression studies focus on the search for genes whose mean expression is different between two or more populations of samples in the so-called "differential expression analysis" approach. However, a difference in variance in gene expression may also be biologically and physiologically relevant. In the classical statistical model used to analyze RNA-sequencing (RNA-seq) data, the dispersion, which defines the variance, is only considered as a parameter to be estimated prior to identifying a difference in mean expression between conditions of interest. Here, we propose to evaluate four recently published methods, which detect differences in both the mean and dispersion in RNA-seq data. We thoroughly investigated the performance of these methods on simulated datasets and characterized parameter settings to reliably detect genes with a differential expression dispersion. We applied these methods to The Cancer Genome Atlas datasets. Interestingly, among the genes with an increased expression dispersion in tumors and without a change in mean expression, we identified some key cellular functions, most of which were related to catabolism and were overrepresented in most of the analyzed cancers. In particular, our results highlight autophagy, whose role in cancerogenesis is context-dependent, illustrating the potential of the differential dispersion approach to gain new insights into biological processes and to discover new biomarkers.
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Affiliation(s)
- Christophe Le Priol
- Univ. Grenoble Alpes, INSERM, CEA-IRIG, Biomics, Grenoble, France
- * E-mail: (CLP); (XG)
| | - Chloé-Agathe Azencott
- Center for Computational Biology, Mines ParisTech, PSL Research University, Paris, France
- Institut Curie, Paris, France
- INSERM U900, Paris, France
| | - Xavier Gidrol
- Univ. Grenoble Alpes, INSERM, CEA-IRIG, Biomics, Grenoble, France
- * E-mail: (CLP); (XG)
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6
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Jackson R, Rajadhyaksha EV, Loeffler RS, Flores CE, Van Doorslaer K. Characterization of 3D organotypic epithelial tissues reveals tonsil-specific differences in tonic interferon signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.19.524743. [PMID: 36711548 PMCID: PMC9882319 DOI: 10.1101/2023.01.19.524743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
Three-dimensional (3D) culturing techniques can recapitulate the stratified nature of multicellular epithelial tissues. Organotypic 3D epithelial tissue culture methods have several applications, including the study of tissue development and function, drug discovery and toxicity testing, host-pathogen interactions, and the development of tissue-engineered constructs for use in regenerative medicine. We grew 3D organotypic epithelial tissues from foreskin, cervix, and tonsil-derived primary cells and characterized the transcriptome of these in vitro tissue equivalents. Using the same 3D culturing method, all three tissues yielded stratified squamous epithelium, validated histologically using basal and superficial epithelial cell markers. The goal of this study was to use RNA-seq to compare gene expression patterns in these three types of epithelial tissues to gain a better understanding of the molecular mechanisms underlying their function and identify potential therapeutic targets for various diseases. Functional profiling by over-representation and gene set enrichment analysis revealed tissue-specific differences: i.e. , cutaneous homeostasis and lipid metabolism in foreskin, extracellular matrix remodeling in cervix, and baseline innate immune differences in tonsil. Specifically, tonsillar epithelia may play an active role in shaping the immune microenvironment of the tonsil balancing inflammation and immune responses in the face of constant exposure to microbial insults. Overall, these data serve as a resource, with gene sets made available for the research community to explore, and as a foundation for understanding the epithelial heterogeneity and how it may impact their in vitro use. An online resource is available to investigate these data ( https://viz.datascience.arizona.edu/3DEpiEx/ ).
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Affiliation(s)
- Robert Jackson
- School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ, USA
- BIO5 Institute, University of Arizona, Tucson, AZ, USA
| | - Esha V Rajadhyaksha
- College of Medicine and College of Science, University of Arizona, Tucson, AZ, USA
| | - Reid S Loeffler
- Biosystems Engineering, College of Agriculture and Life Sciences; College of Engineering, University of Arizona, Tucson, AZ, USA
| | - Caitlyn E Flores
- School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ, USA
| | - Koenraad Van Doorslaer
- School of Animal and Comparative Biomedical Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ, USA
- BIO5 Institute, University of Arizona, Tucson, AZ, USA
- Department of Immunobiology; Cancer Biology Graduate Interdisciplinary Program; Genetics Graduate Interdisciplinary Program; and University of Arizona Cancer Center, University of Arizona, Tucson, AZ USA
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Nguyen T, Yue Z, Slominski R, Welner R, Zhang J, Chen JY. WINNER: A network biology tool for biomolecular characterization and prioritization. Front Big Data 2022; 5:1016606. [DOI: 10.3389/fdata.2022.1016606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022] Open
Abstract
Background and contributionIn network biology, molecular functions can be characterized by network-based inference, or “guilt-by-associations.” PageRank-like tools have been applied in the study of biomolecular interaction networks to obtain further the relative significance of all molecules in the network. However, there is a great deal of inherent noise in widely accessible data sets for gene-to-gene associations or protein-protein interactions. How to develop robust tests to expand, filter, and rank molecular entities in disease-specific networks remains an ad hoc data analysis process.ResultsWe describe a new biomolecular characterization and prioritization tool called Weighted In-Network Node Expansion and Ranking (WINNER). It takes the input of any molecular interaction network data and generates an optionally expanded network with all the nodes ranked according to their relevance to one another in the network. To help users assess the robustness of results, WINNER provides two different types of statistics. The first type is a node-expansion p-value, which helps evaluate the statistical significance of adding “non-seed” molecules to the original biomolecular interaction network consisting of “seed” molecules and molecular interactions. The second type is a node-ranking p-value, which helps evaluate the relative statistical significance of the contribution of each node to the overall network architecture. We validated the robustness of WINNER in ranking top molecules by spiking noises in several network permutation experiments. We have found that node degree–preservation randomization of the gene network produced normally distributed ranking scores, which outperform those made with other gene network randomization techniques. Furthermore, we validated that a more significant proportion of the WINNER-ranked genes was associated with disease biology than existing methods such as PageRank. We demonstrated the performance of WINNER with a few case studies, including Alzheimer's disease, breast cancer, myocardial infarctions, and Triple negative breast cancer (TNBC). In all these case studies, the expanded and top-ranked genes identified by WINNER reveal disease biology more significantly than those identified by other gene prioritizing software tools, including Ingenuity Pathway Analysis (IPA) and DiAMOND.ConclusionWINNER ranking strongly correlates to other ranking methods when the network covers sufficient node and edge information, indicating a high network quality. WINNER users can use this new tool to robustly evaluate a list of candidate genes, proteins, or metabolites produced from high-throughput biology experiments, as long as there is available gene/protein/metabolic network information.
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8
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Xuan R, Chao T, Zhao X, Wang A, Chu Y, Li Q, Zhao Y, Ji Z, Wang J. Transcriptome profiling of the nonlactating mammary glands of dairy goats reveals the molecular genetic mechanism of mammary cell remodeling. J Dairy Sci 2022; 105:5238-5260. [DOI: 10.3168/jds.2021-21039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 01/12/2022] [Indexed: 11/19/2022]
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9
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Goll JB, Bosinger SE, Jensen TL, Walum H, Grimes T, Tharp GK, Natrajan MS, Blazevic A, Head RD, Gelber CE, Steenbergen KJ, Patel NB, Sanz P, Rouphael NG, Anderson EJ, Mulligan MJ, Hoft DF. The Vacc-SeqQC project: Benchmarking RNA-Seq for clinical vaccine studies. Front Immunol 2022; 13:1093242. [PMID: 36741404 PMCID: PMC9893923 DOI: 10.3389/fimmu.2022.1093242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/30/2022] [Indexed: 01/20/2023] Open
Abstract
Introduction Over the last decade, the field of systems vaccinology has emerged, in which high throughput transcriptomics and other omics assays are used to probe changes of the innate and adaptive immune system in response to vaccination. The goal of this study was to benchmark key technical and analytical parameters of RNA sequencing (RNA-seq) in the context of a multi-site, double-blind randomized vaccine clinical trial. Methods We collected longitudinal peripheral blood mononuclear cell (PBMC) samples from 10 subjects before and after vaccination with a live attenuated Francisella tularensis vaccine and performed RNA-Seq at two different sites using aliquots from the same sample to generate two replicate datasets (5 time points for 50 samples each). We evaluated the impact of (i) filtering lowly-expressed genes, (ii) using external RNA controls, (iii) fold change and false discovery rate (FDR) filtering, (iv) read length, and (v) sequencing depth on differential expressed genes (DEGs) concordance between replicate datasets. Using synthetic mRNA spike-ins, we developed a method for empirically establishing minimal read-count thresholds for maintaining fold change accuracy on a per-experiment basis. We defined a reference PBMC transcriptome by pooling sequence data and established the impact of sequencing depth and gene filtering on transcriptome representation. Lastly, we modeled statistical power to detect DEGs for a range of sample sizes, effect sizes, and sequencing depths. Results and Discussion Our results showed that (i) filtering lowly-expressed genes is recommended to improve fold-change accuracy and inter-site agreement, if possible guided by mRNA spike-ins (ii) read length did not have a major impact on DEG detection, (iii) applying fold-change cutoffs for DEG detection reduced inter-set agreement and should be used with caution, if at all, (iv) reduction in sequencing depth had a minimal impact on statistical power but reduced the identifiable fraction of the PBMC transcriptome, (v) after sample size, effect size (i.e. the magnitude of fold change) was the most important driver of statistical power to detect DEG. The results from this study provide RNA sequencing benchmarks and guidelines for planning future similar vaccine studies.
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Affiliation(s)
- Johannes B Goll
- Department of Biomedical Data Science and Bioinformatics, The Emmes Company, LLC, Rockville, MD, United States
| | - Steven E Bosinger
- Division of Microbiology & Immunology, Emory National Primate Research Center, Emory University, Atlanta, GA, United States.,Department of Pathology & Laboratory Medicine, School of Medicine, Emory University, Atlanta, GA, United States.,Emory NPRC Genomics Core, Emory National Primate Research Center, Emory University, Atlanta, GA, United States.,Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA, United States
| | - Travis L Jensen
- Department of Biomedical Data Science and Bioinformatics, The Emmes Company, LLC, Rockville, MD, United States
| | - Hasse Walum
- Division of Microbiology & Immunology, Emory National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Tyler Grimes
- Department of Biomedical Data Science and Bioinformatics, The Emmes Company, LLC, Rockville, MD, United States
| | - Gregory K Tharp
- Emory NPRC Genomics Core, Emory National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Muktha S Natrajan
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA, United States.,Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - Azra Blazevic
- Division of Infectious Diseases, Allergy, and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, United States
| | - Richard D Head
- McDonnell Genome Institute, Washington University, St. Louis, MO, United States
| | - Casey E Gelber
- Department of Biomedical Data Science and Bioinformatics, The Emmes Company, LLC, Rockville, MD, United States
| | - Kristen J Steenbergen
- Department of Biomedical Data Science and Bioinformatics, The Emmes Company, LLC, Rockville, MD, United States
| | - Nirav B Patel
- Emory NPRC Genomics Core, Emory National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Patrick Sanz
- Office of Biodefense, Research Resources and Translational Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | - Nadine G Rouphael
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA, United States.,Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, United States.,Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA, United States
| | - Evan J Anderson
- Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA, United States.,Center for Childhood Infections and Vaccines (CCIV) of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Mark J Mulligan
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA, United States.,Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, United States.,Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA, United States.,New York University Vaccine Center, New York, NY, United States
| | - Daniel F Hoft
- Division of Infectious Diseases, Allergy, and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, United States.,Department of Molecular Microbiology & Immunology, Saint Louis University, St. Louis, MO, United States
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RNA-seq for revealing the function of the transcriptome. Bioinformatics 2022. [DOI: 10.1016/b978-0-323-89775-4.00002-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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11
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Hoffman GE, Roussos P. Dream: powerful differential expression analysis for repeated measures designs. Bioinformatics 2021; 37:192-201. [PMID: 32730587 DOI: 10.1093/bioinformatics/btaa687] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 07/13/2020] [Accepted: 07/23/2020] [Indexed: 01/08/2023] Open
Abstract
SUMMARY Large-scale transcriptome studies with multiple samples per individual are widely used to study disease biology. Yet, current methods for differential expression are inadequate for cross-individual testing for these repeated measures designs. Most problematic, we observe across multiple datasets that current methods can give reproducible false-positive findings that are driven by genetic regulation of gene expression, yet are unrelated to the trait of interest. Here, we introduce a statistical software package, dream, that increases power, controls the false positive rate, enables multiple types of hypothesis tests, and integrates with standard workflows. In 12 analyses in 6 independent datasets, dream yields biological insight not found with existing software while addressing the issue of reproducible false-positive findings. AVAILABILITY AND IMPLEMENTATION Dream is available within the variancePartition Bioconductor package at http://bioconductor.org/packages/variancePartition. CONTACT gabriel.hoffman@mssm.edu. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Gabriel E Hoffman
- Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Panos Roussos
- Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Mental Illness Research, Education, and Clinical Center (VISN 2 South), James J. Peters VA Medical Center, Bronx, NY 10468, USA
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12
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de Castro TBR, Canesso MCC, Boroni M, Chame DF, Souza DDL, de Toledo NE, Tahara EB, Pena SD, Machado CR, Chiari E, Macedo A, Franco GR. Differential Modulation of Mouse Heart Gene Expression by Infection With Two Trypanosoma cruzi Strains: A Transcriptome Analysis. Front Genet 2020; 11:1031. [PMID: 33088283 PMCID: PMC7495023 DOI: 10.3389/fgene.2020.01031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 08/11/2020] [Indexed: 12/17/2022] Open
Abstract
The protozoan Trypanosoma cruzi (T. cruzi) is a well-adapted parasite to mammalian hosts and the pathogen of Chagas disease in humans. As both host and T. cruzi are highly genetically diverse, many variables come into play during infection, making disease outcomes difficult to predict. One important challenge in the field of Chagas disease research is determining the main factors leading to parasite establishment in the chronic stage in some organs, mainly the heart and/or digestive system. Our group previously showed that distinct strains of T. cruzi (JG and Col1.7G2) acquired differential tissue distribution in the chronic stage in dually infected BALB/c mice. To investigate changes in the host triggered by the two distinct T. cruzi strains, we assessed the gene expression profiles of BALB/c mouse hearts infected with either JG, Col1.7G2 or an equivalent mixture of both parasites during the initial phase of infection. This study demonstrates the clear differences in modulation of host gene expression by both parasites. Col1.7G2 strongly activated Th1-polarized immune signature genes, whereas JG caused only minor activation of the host immune response. Moreover, JG strongly reduced the expression of genes encoding ribosomal proteins and mitochondrial proteins related to the electron transport chain. Interestingly, the evaluation of gene expression in mice inoculated with a mixture of the parasites produced expression profiles with both up- and downregulated genes, indicating the coexistence of both parasite strains in the heart during the acute phase. This study suggests that different strains of T. cruzi may be distinguished by their efficiency in activating the immune system, modulating host energy metabolism and reactive oxygen species production and decreasing protein synthesis during early infection, which may be crucial for parasite persistence in specific organs.
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Affiliation(s)
| | | | - Mariana Boroni
- Laboratório de Bioinformática e Biologia Computacional, Centro de Pesquisas, Instituto Nacional de Câncer, Rio de Janeiro, Brazil
| | - Daniela Ferreira Chame
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Brazil
| | - Daniela de Laet Souza
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Brazil
| | - Nayara Evelin de Toledo
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Brazil
| | - Eric Birelli Tahara
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Brazil
| | - Sergio Danilo Pena
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Brazil
| | - Carlos Renato Machado
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Brazil
| | - Egler Chiari
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Brazil
| | - Andrea Macedo
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Brazil
| | - Gloria Regina Franco
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Brazil
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Yu L, Fernandez S, Brock G. Power analysis for RNA-Seq differential expression studies using generalized linear mixed effects models. BMC Bioinformatics 2020; 21:198. [PMID: 32429934 PMCID: PMC7236949 DOI: 10.1186/s12859-020-3541-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 05/07/2020] [Indexed: 11/10/2022] Open
Abstract
Background Power analysis becomes an inevitable step in experimental design of current biomedical research. Complex designs allowing diverse correlation structures are commonly used in RNA-Seq experiments. However, the field currently lacks statistical methods to calculate sample size and estimate power for RNA-Seq differential expression studies using such designs. To fill the gap, simulation based methods have a great advantage by providing numerical solutions, since theoretical distributions of test statistics are typically unavailable for such designs. Results In this paper, we propose a novel simulation based procedure for power estimation of differential expression with the employment of generalized linear mixed effects models for correlated expression data. We also propose a new procedure for power estimation of differential expression with the use of a bivariate negative binomial distribution for paired designs. We compare the performance of both the likelihood ratio test and Wald test under a variety of simulation scenarios with the proposed procedures. The simulated distribution was used to estimate the null distribution of test statistics in order to achieve the desired false positive control and was compared to the asymptotic Chi-square distribution. In addition, we applied the procedure for paired designs to the TCGA breast cancer data set. Conclusions In summary, we provide a framework for power estimation of RNA-Seq differential expression under complex experimental designs. Simulation results demonstrate that both the proposed procedures properly control the false positive rate at the nominal level.
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Affiliation(s)
- Lianbo Yu
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, 1800 Cannon Dr., Columbus, 43210, OH, USA.
| | - Soledad Fernandez
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, 1800 Cannon Dr., Columbus, 43210, OH, USA
| | - Guy Brock
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, 1800 Cannon Dr., Columbus, 43210, OH, USA
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14
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Chowdhury HA, Bhattacharyya DK, Kalita JK. Differential Expression Analysis of RNA-seq Reads: Overview, Taxonomy, and Tools. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2020; 17:566-586. [PMID: 30281477 DOI: 10.1109/tcbb.2018.2873010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Analysis of RNA-sequence (RNA-seq) data is widely used in transcriptomic studies and it has many applications. We review RNA-seq data analysis from RNA-seq reads to the results of differential expression analysis. In addition, we perform a descriptive comparison of tools used in each step of RNA-seq data analysis along with a discussion of important characteristics of these tools. A taxonomy of tools is also provided. A discussion of issues in quality control and visualization of RNA-seq data is also included along with useful tools. Finally, we provide some guidelines for the RNA-seq data analyst, along with research issues and challenges which should be addressed.
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Abstract
PURPOSE OF REVIEW The goal of this paper is to review state-of-the-art transcriptome profiling methods and their recent applications in the field of skeletal biology. RECENT FINDINGS Next-generation sequencing of mRNA (RNA-seq) methods have been established and routinely used in skeletal biology research. RNA-seq has led to the identification of novel genes and transcription factors involved in skeletal development and disease, through its application in small and large animal models, as well as human tissue and cells. With the availability of advanced techniques such as single-cell RNA-seq, novel cell types in skeletal tissues are being identified. As the sequencing technologies are rapidly evolving, the exciting discoveries supported by transcriptomics will continue to emerge and improve our understanding of the biology of the skeleton.
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Affiliation(s)
- Ugur Ayturk
- Musculoskeletal Integrity Program, Hospital for Special Surgery, 515 East 71st St. Suite 403, New York, NY, 10021, USA.
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16
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El Amrani K, Alanis-Lobato G, Mah N, Kurtz A, Andrade-Navarro MA. Detection of condition-specific marker genes from RNA-seq data with MGFR. PeerJ 2019; 7:e6970. [PMID: 31179178 PMCID: PMC6542349 DOI: 10.7717/peerj.6970] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 04/07/2019] [Indexed: 12/19/2022] Open
Abstract
The identification of condition-specific genes is key to advancing our understanding of cell fate decisions and disease development. Differential gene expression analysis (DGEA) has been the standard tool for this task. However, the amount of samples that modern transcriptomic technologies allow us to study, makes DGEA a daunting task. On the other hand, experiments with low numbers of replicates lack the statistical power to detect differentially expressed genes. We have previously developed MGFM, a tool for marker gene detection from microarrays, that is particularly useful in the latter case. Here, we have adapted the algorithm behind MGFM to detect markers in RNA-seq data. MGFR groups samples with similar gene expression levels and flags potential markers of a sample type if their highest expression values represent all replicates of this type. We have benchmarked MGFR against other methods and found that its proposed markers accurately characterize the functional identity of different tissues and cell types in standard and single cell RNA-seq datasets. Then, we performed a more detailed analysis for three of these datasets, which profile the transcriptomes of different human tissues, immune and human blastocyst cell types, respectively. MGFR’s predicted markers were compared to gold-standard lists for these datasets and outperformed the other marker detectors. Finally, we suggest novel candidate marker genes for the examined tissues and cell types. MGFR is implemented as a freely available Bioconductor package (https://doi.org/doi:10.18129/B9.bioc.MGFR), which facilitates its use and integration with bioinformatics pipelines.
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Affiliation(s)
- Khadija El Amrani
- Berlin Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Nancy Mah
- Berlin Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Andreas Kurtz
- Berlin Brandenburg Center for Regenerative Therapies (BCRT), Charité-Universitätsmedizin Berlin, Berlin, Germany
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17
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Hovhannisyan H, Gabaldón T. Transcriptome Sequencing Approaches to Elucidate Host-Microbe Interactions in Opportunistic Human Fungal Pathogens. Curr Top Microbiol Immunol 2019; 422:193-235. [PMID: 30128828 DOI: 10.1007/82_2018_122] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Infections caused by opportunistic human fungal pathogens are a source of increasing medical concern, due to their growing incidence, the emergence of novel pathogenic species, and the lack of effective diagnostics tools. Fungal pathogens are phylogenetically diverse, and their virulence mechanisms can differ widely across species. Despite extensive efforts, the molecular bases of virulence in pathogenic fungi and their interactions with the human host remain poorly understood for most species. In this context, next-generation sequencing approaches hold the promise of helping to close this knowledge gap. In particular, high-throughput transcriptome sequencing (RNA-Seq) enables monitoring the transcriptional profile of both host and microbes to elucidate their interactions and discover molecular mechanisms of virulence and host defense. Here, we provide an overview of transcriptome sequencing techniques and approaches, and survey their application in studying the interplay between humans and fungal pathogens. Finally, we discuss novel RNA-Seq approaches in studying host-pathogen interactions and their potential role in advancing the clinical diagnostics of fungal infections.
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Affiliation(s)
- Hrant Hovhannisyan
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
| | - Toni Gabaldón
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain.
- Universitat Pompeu Fabra, Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain.
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18
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Zinna R, Emlen D, Lavine LC, Johns A, Gotoh H, Niimi T, Dworkin I. Sexual dimorphism and heightened conditional expression in a sexually selected weapon in the Asian rhinoceros beetle. Mol Ecol 2018; 27:5049-5072. [PMID: 30357984 DOI: 10.1111/mec.14907] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/27/2018] [Accepted: 10/01/2018] [Indexed: 12/12/2022]
Abstract
Among the most dramatic examples of sexual selection are the weapons used in battles between rival males over access to females. As with ornaments of female choice, the most "exaggerated" sexually selected weapons vary from male to male more widely than other body parts (hypervariability), and their growth tends to be more sensitive to nutritional state or physiological condition compared with growth of other body parts ("heightened" conditional expression). Here, we use RNAseq analysis to build on recent work exploring these mechanisms in the exaggerated weapons of beetles, by examining patterns of differential gene expression in exaggerated (head and thorax horns) and non-exaggerated (wings, genitalia) traits in the Asian rhinoceros beetle, Trypoxylus dichotomus. Our results suggest that sexually dimorphic expression of weaponry involves large-scale changes in gene expression, relative to other traits, while nutrition-driven changes in gene expression in these same weapons are less pronounced. However, although fewer genes overall were differentially expressed in high- vs. low-nutrition individuals, the number of differentially expressed genes varied predictably according to a trait's degree of condition dependence (head horn > thorax horn > wings > genitalia). Finally, we observed a high degree of similarity in direction of effects (vectors) for subsets of differentially expressed genes across both sexually dimorphic and nutritionally responsive growth. Our results are consistent with a common set of mechanisms governing sexual size dimorphism and condition dependence.
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Affiliation(s)
- Robert Zinna
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Douglas Emlen
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Laura C Lavine
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Annika Johns
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Hiroki Gotoh
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Teruyuki Niimi
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Ian Dworkin
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
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Gao Z, Zhao Z, Tang W. DREAMSeq: An Improved Method for Analyzing Differentially Expressed Genes in RNA-seq Data. Front Genet 2018; 9:588. [PMID: 30559761 PMCID: PMC6284200 DOI: 10.3389/fgene.2018.00588] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/15/2018] [Indexed: 01/09/2023] Open
Abstract
RNA sequencing (RNA-seq) has become a widely used technology for analyzing global gene-expression changes during certain biological processes. It is generally acknowledged that RNA-seq data displays equidispersion and overdispersion characteristics; therefore, most RNA-seq analysis methods were developed based on a negative binomial model capable of capturing both equidispersed and overdispersed data. In this study, we reported that in addition to equidispersion and overdispersion, RNA-seq data also displays underdispersion characteristics that cannot be adequately captured by general RNA-seq analysis methods. Based on a double Poisson model capable of capturing all data characteristics, we developed a new RNA-seq analysis method (DREAMSeq). Comparison of DREAMSeq with five other frequently used RNA-seq analysis methods using simulated datasets showed that its performance was comparable to or exceeded that of other methods in terms of type I error rate, statistical power, receiver operating characteristics (ROC) curve, area under the ROC curve, precision-recall curve, and the ability to detect the number of differentially expressed genes, especially in situations involving underdispersion. These results were validated by quantitative real-time polymerase chain reaction using a real Foxtail dataset. Our findings demonstrated DREAMSeq as a reliable, robust, and powerful new method for RNA-seq data mining. The DREAMSeq R package is available at http://tanglab.hebtu.edu.cn/tanglab/Home/DREAMSeq.
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Affiliation(s)
- Zhihua Gao
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- College of Biological Science and Engineering, Hebei University of Economics and Business, Shijiazhuang, China
| | - Zhiying Zhao
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Wenqiang Tang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
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Expression analysis of RNA sequencing data from human neural and glial cell lines depends on technical replication and normalization methods. BMC Bioinformatics 2018; 19:412. [PMID: 30453873 PMCID: PMC6245503 DOI: 10.1186/s12859-018-2382-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Background The potential for astrocyte participation in central nervous system recovery is highlighted by in vitro experiments demonstrating their capacity to transdifferentiate into neurons. Understanding astrocyte plasticity could be advanced by comparing astrocytes with stem cells. RNA sequencing (RNA-seq) is ideal for comparing differences across cell types. However, this novel multi-stage process has the potential to introduce unwanted technical variation at several points in the experimental workflow. Quantitative understanding of the contribution of experimental parameters to technical variation would facilitate the design of robust RNA-Seq experiments. Results RNA-Seq was used to achieve biological and technical objectives. The biological aspect compared gene expression between normal human fetal-derived astrocytes and human neural stem cells cultured in identical conditions. When differential expression threshold criteria of |log2fold change| > 2 were applied to the data, no significant differences were observed. The technical component quantified variation arising from particular steps in the research pathway, and compared the ability of different normalization methods to reduce unwanted variance. To facilitate this objective, a liberal false discovery rate of 10% and a |log2fold change| > 0.5 were implemented for the differential expression threshold. Data were normalized with RPKM, TMM, and UQS methods using JMP Genomics. The contributions of key replicable experimental parameters (cell lot; library preparation; flow cell) to variance in the data were evaluated using principal variance component analysis. Our analysis showed that, although the variance for every parameter is strongly influenced by the normalization method, the largest contributor to technical variance was library preparation. The ability to detect differentially expressed genes was also affected by normalization; differences were only detected in non-normalized and TMM-normalized data. Conclusions The similarity in gene expression between astrocytes and neural stem cells supports the potential for astrocytic transdifferentiation into neurons, and emphasizes the need to evaluate the therapeutic potential of astrocytes for central nervous system damage. The choice of normalization method influences the contributions to experimental variance as well as the outcomes of differential expression analysis. However irrespective of normalization method, our findings illustrate that library preparation contributed the largest component of technical variance. Electronic supplementary material The online version of this article (10.1186/s12859-018-2382-0) contains supplementary material, which is available to authorized users.
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Zhao S, Li CI, Guo Y, Sheng Q, Shyr Y. RnaSeqSampleSize: real data based sample size estimation for RNA sequencing. BMC Bioinformatics 2018; 19:191. [PMID: 29843589 PMCID: PMC5975570 DOI: 10.1186/s12859-018-2191-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 05/07/2018] [Indexed: 02/08/2023] Open
Abstract
Background One of the most important and often neglected components of a successful RNA sequencing (RNA-Seq) experiment is sample size estimation. A few negative binomial model-based methods have been developed to estimate sample size based on the parameters of a single gene. However, thousands of genes are quantified and tested for differential expression simultaneously in RNA-Seq experiments. Thus, additional issues should be carefully addressed, including the false discovery rate for multiple statistic tests, widely distributed read counts and dispersions for different genes. Results To solve these issues, we developed a sample size and power estimation method named RnaSeqSampleSize, based on the distributions of gene average read counts and dispersions estimated from real RNA-seq data. Datasets from previous, similar experiments such as the Cancer Genome Atlas (TCGA) can be used as a point of reference. Read counts and their dispersions were estimated from the reference’s distribution; using that information, we estimated and summarized the power and sample size. RnaSeqSampleSize is implemented in R language and can be installed from Bioconductor website. A user friendly web graphic interface is provided at http://cqs.mc.vanderbilt.edu/shiny/RnaSeqSampleSize/. Conclusions RnaSeqSampleSize provides a convenient and powerful way for power and sample size estimation for an RNAseq experiment. It is also equipped with several unique features, including estimation for interested genes or pathway, power curve visualization, and parameter optimization. Electronic supplementary material The online version of this article (10.1186/s12859-018-2191-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shilin Zhao
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Chung-I Li
- Department of Statistics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Yan Guo
- Department of Internal Medicine, University of New Mexico, Albuquerque, NM, 87131, USA.,Key Laboratory of Resource Biology and Biotechnology in Western China, School of Life Sciences, Northwest University, Xi'an, 710069, Shanxi, China
| | - Quanhu Sheng
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Yu Shyr
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
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Costa-Silva J, Domingues D, Lopes FM. RNA-Seq differential expression analysis: An extended review and a software tool. PLoS One 2017; 12:e0190152. [PMID: 29267363 PMCID: PMC5739479 DOI: 10.1371/journal.pone.0190152] [Citation(s) in RCA: 295] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 12/08/2017] [Indexed: 12/22/2022] Open
Abstract
The correct identification of differentially expressed genes (DEGs) between specific conditions is a key in the understanding phenotypic variation. High-throughput transcriptome sequencing (RNA-Seq) has become the main option for these studies. Thus, the number of methods and softwares for differential expression analysis from RNA-Seq data also increased rapidly. However, there is no consensus about the most appropriate pipeline or protocol for identifying differentially expressed genes from RNA-Seq data. This work presents an extended review on the topic that includes the evaluation of six methods of mapping reads, including pseudo-alignment and quasi-mapping and nine methods of differential expression analysis from RNA-Seq data. The adopted methods were evaluated based on real RNA-Seq data, using qRT-PCR data as reference (gold-standard). As part of the results, we developed a software that performs all the analysis presented in this work, which is freely available at https://github.com/costasilvati/consexpression. The results indicated that mapping methods have minimal impact on the final DEGs analysis, considering that adopted data have an annotated reference genome. Regarding the adopted experimental model, the DEGs identification methods that have more consistent results were the limma+voom, NOIseq and DESeq2. Additionally, the consensus among five DEGs identification methods guarantees a list of DEGs with great accuracy, indicating that the combination of different methods can produce more suitable results. The consensus option is also included for use in the available software.
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Affiliation(s)
- Juliana Costa-Silva
- Department of Computer Science, Bioinformatics Graduate Program, Federal University of Technology - Paraná, Cornélio Procópio, PR, Brazil
| | - Douglas Domingues
- Department of Computer Science, Bioinformatics Graduate Program, Federal University of Technology - Paraná, Cornélio Procópio, PR, Brazil
- Department of Botany, Institute of Biosciences, São Paulo State University, UNESP, Rio Claro - SP, Brazil
| | - Fabricio Martins Lopes
- Department of Computer Science, Bioinformatics Graduate Program, Federal University of Technology - Paraná, Cornélio Procópio, PR, Brazil
- * E-mail:
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23
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Marsh JW, Humphrys MS, Myers GSA. A Laboratory Methodology for Dual RNA-Sequencing of Bacteria and their Host Cells In Vitro. Front Microbiol 2017; 8:1830. [PMID: 28983295 PMCID: PMC5613115 DOI: 10.3389/fmicb.2017.01830] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 09/06/2017] [Indexed: 12/15/2022] Open
Abstract
Dual RNA-Sequencing leverages established next-generation sequencing (NGS)-enabled RNA-Seq approaches to measure genome-wide transcriptional changes of both an infecting bacteria and host cells. By simultaneously investigating both organisms from the same biological sample, dual RNA-Seq can provide unique insight into bacterial infection processes and reciprocal host responses at once. However, the difficulties involved in handling both prokaryotic and eukaryotic material require distinct, optimized procedures. We previously developed and applied dual RNA-Seq to measure prokaryotic and eukaryotic expression profiles of human cells infected with bacteria, using in vitro Chlamydia-infected epithelial cells as proof of principle. Here we provide a detailed laboratory protocol for in vitro dual RNA-Seq that is readily adaptable to any host-bacteria system of interest.
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Affiliation(s)
- James W Marsh
- School of Life Sciences, The ithree institute, University of Technology SydneyUltimo, NSW, Australia
| | - Michael S Humphrys
- Institute for Genome Sciences, University of Maryland School of MedicineBaltimore, MD, United States
| | - Garry S A Myers
- School of Life Sciences, The ithree institute, University of Technology SydneyUltimo, NSW, Australia
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