Direct nanopore sequencing of mRNA reveals landscape of transcript isoforms in apicomplexan parasites
Details
Publication Year 2021-03-09,Volume 6,Issue #2,Page e01081-20
Journal Title
mSystems
Abstract
Alternative splicing is a widespread phenomenon in metazoans by which single genes are able to produce multiple isoforms of the gene product. However, this has been poorly characterized in apicomplexans, a major phylum of some of the most important global parasites. Efforts have been hampered by atypical transcriptomic features, such as the high AU content of Plasmodium RNA, but also the limitations of short-read sequencing in deciphering complex splicing events. In this study, we utilized the long read direct RNA sequencing platform developed by Oxford Nanopore Technologies to survey the alternative splicing landscape of Toxoplasma gondii and Plasmodium falciparum We find that while native RNA sequencing has a reduced throughput, it allows us to obtain full-length or nearly full-length transcripts with comparable quantification to Illumina sequencing. By comparing these data with available gene models, we find widespread alternative splicing, particularly intron retention, in these parasites. Most of these transcripts contain premature stop codons, suggesting that in these parasites, alternative splicing represents a pathway to transcriptomic diversity, rather than expanding proteomic diversity. Moreover, alternative splicing rates are comparable between parasites, suggesting a shared splicing machinery, despite notable transcriptomic differences between the parasites. This study highlights a strategy in using long-read sequencing to understand splicing events at the whole-transcript level and has implications in the future interpretation of transcriptome sequencing studies.IMPORTANCE We have used a novel nanopore sequencing technology to directly analyze parasite transcriptomes. The very long reads of this technology reveal the full-length genes of the parasites that cause malaria and toxoplasmosis. Gene transcripts must be processed in a process called splicing before they can be translated to protein. Our analysis reveals that these parasites very frequently only partially process their gene products, in a manner that departs dramatically from their human hosts.
Publisher
ASM
Keywords
Plasmodium; RNA splicing; RNA-seq; Toxoplasma; nanopore; transcriptional regulation
Research Division(s)
Population Health And Immunity; Infectious Diseases And Immune Defence
PubMed ID
33688018
Open Access at Publisher's Site
https://doi.org/10.1128/mSystems.01081-20
Terms of Use/Rights Notice
Refer to copyright notice on published article.


Creation Date: 2021-05-13 09:20:18
Last Modified: 2021-05-13 10:00:39
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