Adam Voshall

By Adam Voshall and Etsuko N. Moriyama

Accurate and comprehensive transcriptome assemblies lay the foundation for a range of analyses, such as differential gene expression analysis, metabolic pathway reconstruction, novel gene discovery, or metabolic flux analysis. With the arrival of next-generation sequencing technologies, it has become possible to acquire the whole transcriptome data rapidly even from non-model organisms. However, the problem of accurately assembling the transcriptome for any given sample remains extremely challenging, especially in species with a high prevalence of recent gene or genome duplications, those with alternative splicing of transcripts, or those whose genomes are not well studied. In this chapter, we provided a detailed overview of the strategies used for transcriptome assembly. We reviewed the different statistics available for measuring the quality of transcriptome assemblies with the emphasis on the types of errors each statistic does and does not detect. We also reviewed simulation protocols to computationally generate RNAseq data that present biologically realistic problems such as gene expression bias and alternative splicing. Using such simulated RNAseq data, we presented a comparison of the accuracy, strengths, and weaknesses of nine representative transcriptome assemblers including de novo, genome-guided, and ensemble methods.

Part of the book: Bioinformatics in the Era of Post Genomics and Big Data