# Expression Divergence Measured by Transcriptome Sequencing of Four Yeast Species

 Title: Expression Divergence Measured by Transcriptome Sequencing of Four Yeast Species Author: Busby, Michele A; Costa, Allen M; Stewart, Chip; Stromberg, Michael P; Barnett, Derek; Chuang, Jeffrey H; Marth, Gabor T; Gray, Jesse M.; Springer, Michael Note: Order does not necessarily reflect citation order of authors. Citation: Busby, Michele A., Jesse M. Gray, Allen M. Costa, Chip Stewart, Michael P. Stromberg, Derek Barnett, Jeffrey H. Chuang, Michael Springer, and Gabor T. Marth. 2011. Expression divergence measured by transcriptome sequencing of four yeast species. BMC Genomics 12: 635. Full Text & Related Files: 3296765.pdf (921.9Kb; PDF) Abstract: Background: The evolution of gene expression is a challenging problem in evolutionary biology, for which accurate, well-calibrated measurements and methods are crucial. Results: We quantified gene expression with whole-transcriptome sequencing in four diploid, prototrophic strains of Saccharomyces species grown under the same condition to investigate the evolution of gene expression. We found that variation in expression is gene-dependent with large variations in each gene's expression between replicates of the same species. This confounds the identification of genes differentially expressed across species. To address this, we developed a statistical approach to establish significance bounds for inter-species differential expression in RNA-Seq data based on the variance measured across biological replicates. This metric estimates the combined effects of technical and environmental variance, as well as Poisson sampling noise by isolating each component. Despite a paucity of large expression changes, we found a strong correlation between the variance of gene expression change and species divergence ($$R^2$$ = 0.90). Conclusion: We provide an improved methodology for measuring gene expression changes in evolutionary diverged species using RNA Seq, where experimental artifacts can mimic evolutionary effects. Published Version: doi:10.1186/1471-2164-12-635 Other Sources: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3296765/pdf/ Terms of Use: This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:10304416 Downloads of this work: