Transcript nuclear retention effects quantification of gene expression levels
(English)Manuscript (preprint) (Other academic)
The majority of published differential gene expression studies have used RNA isolated from whole cell extracts (total RNA), overlooking the potential impact of including the nuclear transcriptome in the analyses. It has not been firmly established that the contribution of nuclear RNA is negligible or how the inclusion of it affects quantification of gene expression. Previous studies have estimated that the nuclear transcriptome is five to ten times more complex than the cytoplasmic . Hence, RNA purified solely from the cytoplasm should have fewer unique transcripts, resulting in more sequence counts per transcript and resulting in increased power to detect remaining transcripts. In this study, cytoplasmic and total mRNA have been prepared from three human cell‐lines and sequenced using massive parallel sequencing. The resulting sequence data was analyzed regarding the effect of number of biological replicates, read length and transcripts fractionation on calling differentially detected genes. In addition, the impact of length and secondary structure of mRNAs un‐translated regions (UTRs), and coding sequence length on nucleus to cytoplasm transportation rates of mRNAs was studied. We observe that the number of differentially detected genes was not significantly increased by adding more than three biological replicates or by increasing the sequence read length > 35bp. More differentially detected genes were found in the cytoplasmic RNA compared to the total RNA and a nuclear retention effect was observed for transcripts with long and structured 5’‐ and 3’‐UTR or long protein coding sequences.
RNA, RNA-Seq, transcriptome, nuclear retention
IdentifiersURN: urn:nbn:se:kth:diva-48039OAI: oai:DiVA.org:kth-48039DiVA: diva2:456657
QS 20112011-11-152011-11-152011-11-15Bibliographically approved