RNA sequencing is a powerful tool for teasing apart the genetic mechanisms that underpin variation in gene expression, two Nature papers demonstrate.
Gene expression is the process by which information contained inside genes is used to make functional products such as proteins. This involves the transcription of DNA to RNA, which is then edited or ‘spliced' en route to make the final protein product. Until now, studies of human gene expression variation have been done using microarrays, which tend to measure expression levels using one or a few probes targeting particular parts of each gene.
RNA sequencing, in contrast, allows expression levels to be measured across the entire length of a transcript. Joseph K. Pickrell and colleagues sequenced RNA from 69 cell lines derived from unrelated Nigerian individuals for whom extensive genotype information is known. By pooling the data together, the authors were able to identify many genetic determinants of gene expression variation, a goal that is central to medical and evolutionary genetics. Emmanouil T. Dermitzakis and colleagues characterize the messenger RNA (mRNA) of 60 Caucasian individuals. They provide a fine-scale view of RNA and identify genetic variants that affect its protein-expressing capacities.
The teams demonstrate several advantages of the technique, including increased sensitivity to detect variation in splicing and identify new transcripts. They also identify more than a thousand genes at which genetic variation influences overall expression levels or splicing.
Joseph Pickrell (University of Chicago, IL, USA) Author paper 
Emmanouil Dermitzakis (University of Geneva, Switzerland) Author paper 
Abstracts available online:
Paper 1 Abstract.
Paper 2 Abstract.
(C) Nature press release.
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