GAGE: A critical evaluation of genome assemblies and assembly algorithms

Salzberg, S. L., Phillippy, A. M., Zimin, A., Puiu, D., Magoc, T., Koren, S., Treangen, T. J., Schatz, M. C., Delcher, A. L., Roberts, M., Marcais, G., Pop, M., Yorke, J. A. (March 2012) GAGE: A critical evaluation of genome assemblies and assembly algorithms. Genome Res, 22 (3). pp. 557-67. ISSN 1549-5469 (Electronic)1088-9051 (Linking)

[thumbnail of Paper] PDF (Paper)
GAGE A critical evaluation of genome assemblies.pdf - Published Version
Restricted to Repository staff only

Download (1MB)

Abstract

New sequencing technology has dramatically altered the landscape of whole-genome sequencing, allowing scientists to initiate numerous projects to decode the genomes of previously unsequenced organisms. The lowest-cost technology can generate deep coverage of most species, including mammals, in just a few days. The sequence data generated by one of these projects consist of millions or billions of short DNA sequences (reads) that range from 50 to 150 nt in length. These sequences must then be assembled de novo before most genome analyses can begin. Unfortunately, genome assembly remains a very difficult problem, made more difficult by shorter reads and unreliable long-range linking information. In this study, we evaluated several of the leading de novo assembly algorithms on four different short-read data sets, all generated by Illumina sequencers. Our results describe the relative performance of the different assemblers as well as other significant differences in assembly difficulty that appear to be inherent in the genomes themselves. Three overarching conclusions are apparent: first, that data quality, rather than the assembler itself, has a dramatic effect on the quality of an assembled genome; second, that the degree of contiguity of an assembly varies enormously among different assemblers and different genomes; and third, that the correctness of an assembly also varies widely and is not well correlated with statistics on contiguity. To enable others to replicate our results, all of our data and methods are freely available, as are all assemblers used in this study.

Item Type: Paper
Subjects: bioinformatics > genomics and proteomics > alignment > sequence alignment
bioinformatics > genomics and proteomics > annotation > sequence annotation
bioinformatics > genomics and proteomics > analysis and processing > Sequence Data Processing
bioinformatics > genomics and proteomics > Mapping and Rendering > Sequence Rendering
CSHL Authors:
Communities: CSHL labs > Schatz lab
CSHL Cancer Center Program > Cancer Genetics
Depositing User: CSHL Librarian
Date: March 2012
Date Deposited: 16 Mar 2012 13:30
Last Modified: 14 Oct 2015 20:38
PMCID: PMC3290791
URI: https://repository.cshl.edu/id/eprint/25380

Actions (login required)

Administrator's edit/view item Administrator's edit/view item