ALL Metrics
-
Views
-
Downloads
Get PDF
Get XML
Cite
Export
Track
Software Tool Article
Revised

Gene expression data visualization tool on the o²S²PARC platform

[version 2; peer review: 2 approved]
PUBLISHED 06 Feb 2023
Author details Author details
OPEN PEER REVIEW
REVIEWER STATUS

This article is included in the Bioinformatics gateway.

This article is included in the Genomics and Genetics gateway.

Abstract

Background: The identification of differentially expressed genes and their associated biological processes, molecular function, and cellular components are essential for genetic disease studies because they present potential biomarkers and therapeutic targets.
Methods: In this study, we developed an o²S²PARC template to instantiate an interactive pipeline for gene expression data visualization, ontological mapping, and statistical evaluation. To demonstrate the tool's usefulness, we performed a case study on a publicly available dataset.
Results: The tool enables users to identify the differentially expressed genes (DEGs) and visualize them in a volcano plot format. Ontologies associated with the DEGs are assigned and visualized in barplots.
Conclusions: The “Expression data visualization” template is publicly available on the o²S²PARC platform.

Keywords

Visualization, Gene expression, Ontology, o²S²PARC

Revised Amendments from Version 1

The article is revised according to the reviewers’ suggestions. More information is provided about the platforms, the tool (the function names of the cited Python packages are specified in the “Methods”-“Operation” section), and the browser extension (where the code locates and installation guide notes are amplified in “Methods” –“User guide extension”). We also further explained how to produce and interpret the ontology barplots (in the “Results” section) and the pipeline validation.

See the authors' detailed response to the review by Esra Neufeld
See the authors' detailed response to the review by Joost B. M. Wagenaar

Introduction

Transcriptome data has been used to understand the local microenvironment, molecular signals, and cell-cell interaction in cells, tissues, and organs in multiple diseases, such as Alzheimer’s disease,1 Parkinson’s disease,2 and many more. In this study, we focus on the gene expression data, particularly the differentially expressed genes (DEGs) and their associated ontologies: (i) the cellular component (CC) that describes the subcellular structures and macromolecular complexes, often used to annotate cellular locations of gene products; (ii) the biological process (BP) that describes the biological programs consisting of multiple molecular activities, such as DNA repair or signal transduction; (iii) and the molecular function (MF) that describes molecular-level activities performed by gene products, such as “catalysis” or “transport”.

This study was performed during the Stimulating Peripheral Activity to Relieve Conditions (SPARC) FAIR Codeathon in August 2022 organized by the National Institute of Health (NIH) SPARC program.3 The SPARC program was initiated to advance the understanding of nerve-organ interactions and to expedite the development of innovative therapies and devices that modulate electrical activity in nerves to promote organ function. It has adopted the FAIR data sharing policy (encompasses the principles of Findability, Accessibility, Interoperability, and Reusability), according to the SPARC Data Structure (SDS). Currently, there are multiple transcriptomic datasets available on the SPARC Portal,4 containing a wide range of species from humans, pigs, and mice to rats; anatomical structures include neurons for multiple organs and physiological systems; analysis methods include RNA sequencing, real-time PCR; small molecule FISH (RNAscope) probes, and multiple others.

We developed a gene expression data visualization tool to visualize the transcriptomics data on the SPARC Portal platform and created and published it on the o2S2PARC, Open Online Simulations for Stimulating Peripheral Activity to Relieve Conditions, platform – a simulation and analysis platform designed to study peripheral nerve system neuromodulation/stimulations and its physiological impact on organs.5 The o2S2PARC platform provides simulations in animal/human anatomical models with emulational organ and tissue-specific properties with the permission of conducting experiments from molecules to a body level.5 While the platform currently hosts tools for multiple biological and physiological analyses, it does not provide a tool for transcriptomics and gene expression data analysis or visualization.

In this article, We introduced a publicly available pipeline to visualize gene expression data and a chrome extension that guides the user from downloading the dataset from the SPARC portal to using the tool and generating the data.

Methods

The gene expression data visualization tool template

Implementation

The tool is created as a template on the o2S2PARC platform. The platform is accessible on all common web browsers. The tool makes use of pandas 1.4.3, bioinfokit 2.0.8, numpy 1.22.1, matplotlib 3.5.2, seaborn 0.11.2, and goatools 1.2.3. The required runtime environment is bundled along with the tool and automatically installed.

Operation

The tool includes two pipelines encoded in two separate python jupyterlab notebooks. We used Jupyterlab, as recommended by the o2S2PARC platform, because it provides interactive exploration, along with the possibility of providing guidance and instructions in line with scripted analyses. The first pipeline identifies the DEGs based on statistically determined p-values (by default, a threshold of 5% is applied to determine significance) and determines the expression profile of the genes:

  • p-value > 0.05: “Not differentially expressed”

  • p-value < 0.05 and LogFC (log-fold change) value > 0: “Upregulated”

  • p-value < 0.05 and LogFC value < 0: “Downregulated”

  • The DEGs are represented in a volcano plot generated using the visuz.GeneExpression.volcano() function from the bioinfokit Python package.6

The pipeline also performs the ontology analysis for the differentially expressed genes, to determine the cellular components, biological processes, and molecular functions associated with these genes.

The ontology analysis and result visualization are performed using the goatools.base, goatools.obo_parser, goatools.anno.genetogo_reader, and goatools.goea.go_enrichment_ns functions from the goatools Python package.7

The biological processes, molecular functions, and cellular component ontologies are represented in separate barplots, as in Figure 1. In total six barplots are created, three upregulated genes and three downregulated genes.

b9697086-8b20-45b4-bf2b-1df7e1a7f229_figure1.gif

Figure 1. Example Barplot of statistically significant ontologies associated with differentially expressed genes.

The gene-related ontology data were downloaded from the NCBI database. The file for the human species is provided as default. The user needs to provide a file as input if the transcriptomics data relates to other species.

The second pipeline takes two CSV files as input. The CSV files correspond to gene expression data of a different dataset, to be further compared. Example data files are available in the project GitHub repository.

As in the first pipeline, the gene’s expression profiles and the DEGs are determined for the two datasets, separately. Then, we identified the common genes between the two datasets and those specific genes to one dataset.

Finally, the gene expression profiles in the two datasets are compiled in a single CSV file for further analysis, which includes the expression analysis result of the two combined datasets.

User guide extension

A web browser extension was developed, using HTML and CSS programming to guide users. The extension is helpful for the SPARC platform users. It guides the user step-by-step from downloading transcriptomics data from the SPARC portal database, through a raw-data analysis workflow, to explaining the “Gene expression data visualization” tool.

The extension code could be downloaded from the project GitHub repository and the extension could be installed using the developer mode on any browser. The steps from downloading the code to using the extension are provided in the GitHub repository.

Pipeline validation

The tool was initially created to visualize the SPARC Portal platform transcriptomics data. However, it could be used to visualize any expression data CSV file. The pipeline validation was performed using two datasets from the Gene Expression Omnibus (GEO) database8 corresponding to the early and advanced stages of multiple sclerosis disease (MS) in human patients (GSE 126802 and GSE 10800).

The early-stage dataset GSE1268029 provides microarray gene expression analysis raw data from the subcortical normal-appearing white matter from 18 MS donors and the white matter of 9 control donors. The advanced stage dataset GSE10800010 provides microarray gene expression data from 7 chronic active MS demyelinated lesions, 8 inactive MS lesions, and the white matter of 10 control donors.

The tool was used to visualize the first dataset data, to determine the genes and pathways implicated in the occurrence of the disease. Then we compared the two datasets to determine the genes and pathways implicated in the disease progression.

Results

The tool includes two pipelines, one to visualize the expression data from a single CSV file, and the second to compare two datasets.

The dataset expression data are visualized in a volcano plot format, as represented in Figure 2.

b9697086-8b20-45b4-bf2b-1df7e1a7f229_figure2.gif

Figure 2. Volcano plot generated by the “Gene expression data visualization” tool.

The pipeline also determines the ontologies associated with the DEGs: (i) BP associated with upregulated genes; (ii) MF associated with upregulated genes; (iii) CC associated with upregulated genes; (iv) BP associated with downregulated genes; (v) MF associated with downregulated genes; and (vi) CC associated with downregulated genes. The statistically significant ontologies are represented in six barplots. The y-axis corresponds to the statistically significant ontology names. Also, the x-axis represents the percentage of the genes associated with the ontology per total genes (upregulated or downregulated).

The second pipeline determines the genes with similar expression profiles in the two datasets and most importantly those with different profiles, which is helpful for the comparison of two cells, tissues, or diseases.

It also generates a table summarizing the gene’s count, as represented in Table 1.

Table 1. Table summarizing the numbers of gene groups.

data2_expressionDownregulatedNot differentially expressedUpregulated
data1_expression
Downregulated834104882
Not differentially expressed6850353075292
Upregulated47792415

Pipeline validation

The data analysis was performed for the unique purpose of validating the pipeline. The data and analysis results are available as supplementary materials on the project’s GitHub repository. However, no interpretation was performed since our article focuses on presenting the tool.

The tool is publicly available for all the o2S2PARC platform users. And the user guide Browser extension is available in the project repository.

Discussion and conclusion

Transcriptomics has been increasingly utilized by researchers and clinicians in prioritizing specific systems and networks,2 finding biomarkers,11 developing precision medicine strategies,11 monitoring disease progressions, and predicting treatment effects.12

The expression data visualization tool is useful in helping transform the transcriptome data into visualizable differentially expressed genes (DEGs) and gene ontology (GO) analyses in a one-step standardized process and form. Nowadays, DEGs and GO are commonly utilized tools in detecting potential key pathways, molecules, and cells related to target tissues, organs, and diseases.1114

The tool is build-in/hosted on the o2S2PARC platform. No direct bridge leading the tool from the SPARC portal platform currently exists. The browser extension plays an intermediate role in guiding the users from the SPARC portal toward the tool on the o2S2PARC platform, which is also available on the project GitHub repository.

Our work enhances the usability of the transcriptomics data on the SPARC portal by providing a specific data analysis and visualization tool that does not require any coding skills, to identify the gene expression differences between species, healthy or diseased population groups, individual subjects, and tissues. It also represents an example of how to use and contribute to the development of the o2S2PARC platform.

The current version requires processed gene expression data and only integrates a limited amount of transcriptomic analysis. However, future versions will integrate more features such as data preprocessing.

Comments on this article Comments (0)

Version 2
VERSION 2 PUBLISHED 07 Nov 2022
Comment
Author details Author details
Competing interests
Grant information
Copyright
Download
 
Export To
metrics
Views Downloads
F1000Research - -
PubMed Central
Data from PMC are received and updated monthly.
- -
Citations
CITE
how to cite this article
Ben Aribi H, Ding M and Kiran A. Gene expression data visualization tool on the o²S²PARC platform [version 2; peer review: 2 approved]. F1000Research 2023, 11:1267 (https://doi.org/10.12688/f1000research.126840.2)
NOTE: If applicable, it is important to ensure the information in square brackets after the title is included in all citations of this article.
track
receive updates on this article
Track an article to receive email alerts on any updates to this article.

Open Peer Review

Current Reviewer Status: ?
Key to Reviewer Statuses VIEW
ApprovedThe paper is scientifically sound in its current form and only minor, if any, improvements are suggested
Approved with reservations A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit.
Not approvedFundamental flaws in the paper seriously undermine the findings and conclusions
Version 2
VERSION 2
PUBLISHED 06 Feb 2023
Revised
Views
8
Cite
Reviewer Report 15 Feb 2023
Joost B. M. Wagenaar, Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA, USA 
Approved
VIEWS 8
The authors addressed the comments of the ... Continue reading
CITE
CITE
HOW TO CITE THIS REPORT
Wagenaar JBM. Reviewer Report For: Gene expression data visualization tool on the o²S²PARC platform [version 2; peer review: 2 approved]. F1000Research 2023, 11:1267 (https://doi.org/10.5256/f1000research.143516.r162566)
NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article.
Views
6
Cite
Reviewer Report 13 Feb 2023
Esra Neufeld, Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland 
Approved
VIEWS 6
Thank you very much to the authors for their revision, which addresses nearly all points raised by this reviewer, as well as for the work they have performed and shared. At this point, the article can be indexed as is.
... Continue reading
CITE
CITE
HOW TO CITE THIS REPORT
Neufeld E. Reviewer Report For: Gene expression data visualization tool on the o²S²PARC platform [version 2; peer review: 2 approved]. F1000Research 2023, 11:1267 (https://doi.org/10.5256/f1000research.143516.r162565)
NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article.
Version 1
VERSION 1
PUBLISHED 07 Nov 2022
Views
19
Cite
Reviewer Report 21 Dec 2022
Esra Neufeld, Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland 
Approved with Reservations
VIEWS 19
The present paper discusses a series of workflows established to analyze genetic expression data. They integrate different tools to produce intuitive visualization, help with interpretation, and provide basic statistics. The workflows are made available through an open, online platform (o2S2PARC) ... Continue reading
CITE
CITE
HOW TO CITE THIS REPORT
Neufeld E. Reviewer Report For: Gene expression data visualization tool on the o²S²PARC platform [version 2; peer review: 2 approved]. F1000Research 2023, 11:1267 (https://doi.org/10.5256/f1000research.139290.r155905)
NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article.
  • Author Response 06 Feb 2023
    Jessica Ding
    06 Feb 2023
    Author Response
    We here represent our sincere gratitude toward the reviewer’s advice and corrections.
    Our replies and amendments were made point-by-point according to the review’s proposals.

    1. In general, seeing that ... Continue reading
COMMENTS ON THIS REPORT
  • Author Response 06 Feb 2023
    Jessica Ding
    06 Feb 2023
    Author Response
    We here represent our sincere gratitude toward the reviewer’s advice and corrections.
    Our replies and amendments were made point-by-point according to the review’s proposals.

    1. In general, seeing that ... Continue reading
Views
23
Cite
Reviewer Report 13 Dec 2022
Joost B. M. Wagenaar, Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA, USA 
Approved with Reservations
VIEWS 23
In this article, the authors describe a tool that runs on a platform called O2S2PARC. This tool allows users to visualize gene expression data using some standardized interactive approach. The authors mention that this tool could make it easier for ... Continue reading
CITE
CITE
HOW TO CITE THIS REPORT
Wagenaar JBM. Reviewer Report For: Gene expression data visualization tool on the o²S²PARC platform [version 2; peer review: 2 approved]. F1000Research 2023, 11:1267 (https://doi.org/10.5256/f1000research.139290.r155907)
NOTE: it is important to ensure the information in square brackets after the title is included in all citations of this article.
  • Author Response 06 Feb 2023
    Jessica Ding
    06 Feb 2023
    Author Response
    We are grateful for the advice and questions raised by reviewer 1. Here are our revisions and replies for each point s/he had made.

    1. I am having a ... Continue reading
COMMENTS ON THIS REPORT
  • Author Response 06 Feb 2023
    Jessica Ding
    06 Feb 2023
    Author Response
    We are grateful for the advice and questions raised by reviewer 1. Here are our revisions and replies for each point s/he had made.

    1. I am having a ... Continue reading

Comments on this article Comments (0)

Version 2
VERSION 2 PUBLISHED 07 Nov 2022
Comment
Alongside their report, reviewers assign a status to the article:
Approved - the paper is scientifically sound in its current form and only minor, if any, improvements are suggested
Approved with reservations - A number of small changes, sometimes more significant revisions are required to address specific details and improve the papers academic merit.
Not approved - fundamental flaws in the paper seriously undermine the findings and conclusions
Sign In
If you've forgotten your password, please enter your email address below and we'll send you instructions on how to reset your password.

The email address should be the one you originally registered with F1000.

Email address not valid, please try again

You registered with F1000 via Google, so we cannot reset your password.

To sign in, please click here.

If you still need help with your Google account password, please click here.

You registered with F1000 via Facebook, so we cannot reset your password.

To sign in, please click here.

If you still need help with your Facebook account password, please click here.

Code not correct, please try again
Email us for further assistance.
Server error, please try again.