RNA-seq: impact of RNA degradation on transcript quantification

Background The use of low quality RNA samples in whole-genome gene expression profiling remains controversial. It is unclear if transcript degradation in low quality RNA samples occurs uniformly, in which case the effects of degradation can be corrected via data normalization, or whether different...

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Main Authors: Gallego Romero, Irene, Tung, Jenny, Gilad, Yoav, Pai, Athma A.
Other Authors: Massachusetts Institute of Technology. Department of Biology
Format: Article
Language:English
Published: BioMed Central 2015
Online Access:http://hdl.handle.net/1721.1/97557
https://orcid.org/0000-0002-7995-9948
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author Gallego Romero, Irene
Tung, Jenny
Gilad, Yoav
Pai, Athma A.
author2 Massachusetts Institute of Technology. Department of Biology
author_facet Massachusetts Institute of Technology. Department of Biology
Gallego Romero, Irene
Tung, Jenny
Gilad, Yoav
Pai, Athma A.
author_sort Gallego Romero, Irene
collection MIT
description Background The use of low quality RNA samples in whole-genome gene expression profiling remains controversial. It is unclear if transcript degradation in low quality RNA samples occurs uniformly, in which case the effects of degradation can be corrected via data normalization, or whether different transcripts are degraded at different rates, potentially biasing measurements of expression levels. This concern has rendered the use of low quality RNA samples in whole-genome expression profiling problematic. Yet, low quality samples (for example, samples collected in the course of fieldwork) are at times the sole means of addressing specific questions. Results We sought to quantify the impact of variation in RNA quality on estimates of gene expression levels based on RNA-seq data. To do so, we collected expression data from tissue samples that were allowed to decay for varying amounts of time prior to RNA extraction. The RNA samples we collected spanned the entire range of RNA Integrity Number (RIN) values (a metric commonly used to assess RNA quality). We observed widespread effects of RNA quality on measurements of gene expression levels, as well as a slight but significant loss of library complexity in more degraded samples. Conclusions While standard normalizations failed to account for the effects of degradation, we found that by explicitly controlling for the effects of RIN using a linear model framework we can correct for the majority of these effects. We conclude that in instances in which RIN and the effect of interest are not associated, this approach can help recover biologically meaningful signals in data from degraded RNA samples.
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spelling mit-1721.1/975572022-09-27T21:41:41Z RNA-seq: impact of RNA degradation on transcript quantification Gallego Romero, Irene Tung, Jenny Gilad, Yoav Pai, Athma A. Massachusetts Institute of Technology. Department of Biology Pai, Athma A. Background The use of low quality RNA samples in whole-genome gene expression profiling remains controversial. It is unclear if transcript degradation in low quality RNA samples occurs uniformly, in which case the effects of degradation can be corrected via data normalization, or whether different transcripts are degraded at different rates, potentially biasing measurements of expression levels. This concern has rendered the use of low quality RNA samples in whole-genome expression profiling problematic. Yet, low quality samples (for example, samples collected in the course of fieldwork) are at times the sole means of addressing specific questions. Results We sought to quantify the impact of variation in RNA quality on estimates of gene expression levels based on RNA-seq data. To do so, we collected expression data from tissue samples that were allowed to decay for varying amounts of time prior to RNA extraction. The RNA samples we collected spanned the entire range of RNA Integrity Number (RIN) values (a metric commonly used to assess RNA quality). We observed widespread effects of RNA quality on measurements of gene expression levels, as well as a slight but significant loss of library complexity in more degraded samples. Conclusions While standard normalizations failed to account for the effects of degradation, we found that by explicitly controlling for the effects of RIN using a linear model framework we can correct for the majority of these effects. We conclude that in instances in which RIN and the effect of interest are not associated, this approach can help recover biologically meaningful signals in data from degraded RNA samples. American Heart Association (Predoctoral Fellowship) 2015-06-29T16:37:10Z 2015-06-29T16:37:10Z 2014-05 2014-05 2015-06-29T08:37:57Z Article http://purl.org/eprint/type/JournalArticle 1741-7007 http://hdl.handle.net/1721.1/97557 Gallego Romero, Irene, Athma A Pai, Jenny Tung, and Yoav Gilad. “RNA-Seq: Impact of RNA Degradation on Transcript Quantification.” BMC Biology 12, no. 1 (2014): 42. https://orcid.org/0000-0002-7995-9948 en http://dx.doi.org/10.1186/1741-7007-12-42 BMC Biology Gallego Romero et al.; licensee BioMed Central Ltd. application/pdf BioMed Central
spellingShingle Gallego Romero, Irene
Tung, Jenny
Gilad, Yoav
Pai, Athma A.
RNA-seq: impact of RNA degradation on transcript quantification
title RNA-seq: impact of RNA degradation on transcript quantification
title_full RNA-seq: impact of RNA degradation on transcript quantification
title_fullStr RNA-seq: impact of RNA degradation on transcript quantification
title_full_unstemmed RNA-seq: impact of RNA degradation on transcript quantification
title_short RNA-seq: impact of RNA degradation on transcript quantification
title_sort rna seq impact of rna degradation on transcript quantification
url http://hdl.handle.net/1721.1/97557
https://orcid.org/0000-0002-7995-9948
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