Reference-guided de novo assembly approach improves genome reconstruction for related species.

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Version: Final published version
Serval ID
serval:BIB_993F43E79F3B
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Reference-guided de novo assembly approach improves genome reconstruction for related species.
Journal
BMC Bioinformatics
Author(s)
Lischer HEL, Shimizu K.K.
ISSN
1471-2105 (Electronic)
ISSN-L
1471-2105
Publication state
Published
Issued date
2017
Peer-reviewed
Oui
Volume
18
Number
1
Pages
474
Language
english
Abstract
The development of next-generation sequencing has made it possible to sequence whole genomes at a relatively low cost. However, de novo genome assemblies remain challenging due to short read length, missing data, repetitive regions, polymorphisms and sequencing errors. As more and more genomes are sequenced, reference-guided assembly approaches can be used to assist the assembly process. However, previous methods mostly focused on the assembly of other genotypes within the same species. We adapted and extended a reference-guided de novo assembly approach, which enables the usage of a related reference sequence to guide the genome assembly. In order to compare and evaluate de novo and our reference-guided de novo assembly approaches, we used a simulated data set of a repetitive and heterozygotic plant genome.
The extended reference-guided de novo assembly approach almost always outperforms the corresponding de novo assembly program even when a reference of a different species is used. Similar improvements can be observed in high and low coverage situations. In addition, we show that a single evaluation metric, like the widely used N50 length, is not enough to properly rate assemblies as it not always points to the best assembly evaluated with other criteria. Therefore, we used the summed z-scores of 36 different statistics to evaluate the assemblies.
The combination of reference mapping and de novo assembly provides a powerful tool to improve genome reconstruction by integrating information of a related genome. Our extension of the reference-guided de novo assembly approach enables the application of this strategy not only within but also between related species. Finally, the evaluation of genome assemblies is often not straight forward, as the truth is not known. Thus one should always use a combination of evaluation metrics, which not only try to assess the continuity but also the accuracy of an assembly.

Keywords
Assembly evaluation, De novo, Genome assembly, Reference-guided, Related species
Pubmed
Web of science
Open Access
Yes
Create date
22/11/2017 9:08
Last modification date
20/08/2019 15:00
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