Send to

Choose Destination
Genome Res. 2018 Feb 9. doi: 10.1101/gr.222976.117. [Epub ahead of print]

SQANTI: extensive characterization of long-read transcript sequences for quality control in full-length transcriptome identification and quantification.

Author information

Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, Genetics Institute, University of Florida, Gainesville, Florida 32611, USA.
Genomics of Gene Expression Laboratory, Centro de Investigaciones Principe Felipe (CIPF), 46012 Valencia, Spain.
Neural Regeneration Laboratory, CIPF, 46012 Valencia, Spain.
Department of Developmental and Cell Biology, University of California, Irvine, California 92617, USA.
VIB-UGent Center for Medical Biotechnology, VIB, B-9000 Ghent, Belgium.
Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium.
Centro Nacional de Investigaciones Cardiovasculares CNIC, 28029 Madrid, Spain.
Spanish National Cancer Research Centre (CNIO), 28029 Madrid, Spain.
Gene Expression and mRNA Metabolism Laboratory, CSIC, IBV, 46010 Valencia, Spain.
Gene Expression and mRNA Metabolism Laboratory, CIPF, 46012 Valencia, Spain.


High-throughput sequencing of full-length transcripts using long reads has paved the way for the discovery of thousands of novel transcripts, even in well-annotated mammalian species. The advances in sequencing technology have created a need for studies and tools that can characterize these novel variants. Here, we present SQANTI, an automated pipeline for the classification of long-read transcripts that can assess the quality of data and the preprocessing pipeline using 47 unique descriptors. We apply SQANTI to a neuronal mouse transcriptome using Pacific Biosciences (PacBio) long reads and illustrate how the tool is effective in characterizing and describing the composition of the full-length transcriptome. We perform extensive evaluation of ToFU PacBio transcripts by PCR to reveal that an important number of the novel transcripts are technical artifacts of the sequencing approach and that SQANTI quality descriptors can be used to engineer a filtering strategy to remove them. Most novel transcripts in this curated transcriptome are novel combinations of existing splice sites, resulting more frequently in novel ORFs than novel UTRs, and are enriched in both general metabolic and neural-specific functions. We show that these new transcripts have a major impact in the correct quantification of transcript levels by state-of-the-art short-read-based quantification algorithms. By comparing our iso-transcriptome with public proteomics databases, we find that alternative isoforms are elusive to proteogenomics detection. SQANTI allows the user to maximize the analytical outcome of long-read technologies by providing the tools to deliver quality-evaluated and curated full-length transcriptomes.

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center