A Population Proportion approach for ranking differentially expressed genes

<p>Abstract</p> <p>Background</p> <p>DNA microarrays are used to investigate differences in gene expression between two or more classes of samples. Most currently used approaches compare mean expression levels between classes and are not geared to find genes whose expre...

Full description

Bibliographic Details
Main Author: Gadgil Mugdha
Format: Article
Language:English
Published: BMC 2008-09-01
Series:BMC Bioinformatics
Online Access:http://www.biomedcentral.com/1471-2105/9/380
_version_ 1811278926895382528
author Gadgil Mugdha
author_facet Gadgil Mugdha
author_sort Gadgil Mugdha
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>DNA microarrays are used to investigate differences in gene expression between two or more classes of samples. Most currently used approaches compare mean expression levels between classes and are not geared to find genes whose expression is significantly different in only a subset of samples in a class. However, biological variability can lead to situations where key genes are differentially expressed in only a subset of samples. To facilitate the identification of such genes, a new method is reported.</p> <p>Methods</p> <p>The key difference between the Population Proportion Ranking Method (PPRM) presented here and almost all other methods currently used is in the quantification of variability. PPRM quantifies variability in terms of inter-sample ratios and can be used to calculate the relative merit of differentially expressed genes with a specified difference in expression level between at least some samples in the two classes, which at the same time have lower than a specified variability within each class.</p> <p>Results</p> <p>PPRM is tested on simulated data and on three publicly available cancer data sets. It is compared to the t test, PPST, COPA, OS, ORT and MOST using the simulated data. Under the conditions tested, it performs as well or better than the other methods tested under low intra-class variability and better than t test, PPST, COPA and OS when a gene is differentially expressed in only a subset of samples. It performs better than ORT and MOST in recognizing non differentially expressed genes with high variability in expression levels across all samples. For biological data, the success of predictor genes identified in appropriately classifying an independent sample is reported.</p>
first_indexed 2024-04-13T00:45:35Z
format Article
id doaj.art-9625295591f64d65b0a32a9162d95449
institution Directory Open Access Journal
issn 1471-2105
language English
last_indexed 2024-04-13T00:45:35Z
publishDate 2008-09-01
publisher BMC
record_format Article
series BMC Bioinformatics
spelling doaj.art-9625295591f64d65b0a32a9162d954492022-12-22T03:10:01ZengBMCBMC Bioinformatics1471-21052008-09-019138010.1186/1471-2105-9-380A Population Proportion approach for ranking differentially expressed genesGadgil Mugdha<p>Abstract</p> <p>Background</p> <p>DNA microarrays are used to investigate differences in gene expression between two or more classes of samples. Most currently used approaches compare mean expression levels between classes and are not geared to find genes whose expression is significantly different in only a subset of samples in a class. However, biological variability can lead to situations where key genes are differentially expressed in only a subset of samples. To facilitate the identification of such genes, a new method is reported.</p> <p>Methods</p> <p>The key difference between the Population Proportion Ranking Method (PPRM) presented here and almost all other methods currently used is in the quantification of variability. PPRM quantifies variability in terms of inter-sample ratios and can be used to calculate the relative merit of differentially expressed genes with a specified difference in expression level between at least some samples in the two classes, which at the same time have lower than a specified variability within each class.</p> <p>Results</p> <p>PPRM is tested on simulated data and on three publicly available cancer data sets. It is compared to the t test, PPST, COPA, OS, ORT and MOST using the simulated data. Under the conditions tested, it performs as well or better than the other methods tested under low intra-class variability and better than t test, PPST, COPA and OS when a gene is differentially expressed in only a subset of samples. It performs better than ORT and MOST in recognizing non differentially expressed genes with high variability in expression levels across all samples. For biological data, the success of predictor genes identified in appropriately classifying an independent sample is reported.</p>http://www.biomedcentral.com/1471-2105/9/380
spellingShingle Gadgil Mugdha
A Population Proportion approach for ranking differentially expressed genes
BMC Bioinformatics
title A Population Proportion approach for ranking differentially expressed genes
title_full A Population Proportion approach for ranking differentially expressed genes
title_fullStr A Population Proportion approach for ranking differentially expressed genes
title_full_unstemmed A Population Proportion approach for ranking differentially expressed genes
title_short A Population Proportion approach for ranking differentially expressed genes
title_sort population proportion approach for ranking differentially expressed genes
url http://www.biomedcentral.com/1471-2105/9/380
work_keys_str_mv AT gadgilmugdha apopulationproportionapproachforrankingdifferentiallyexpressedgenes
AT gadgilmugdha populationproportionapproachforrankingdifferentiallyexpressedgenes