Title
Consensus generation and variant detection by Celera Assembler.
Abstract
We present an algorithm to identify allelic variation given a Whole Genome Shotgun (WGS) assembly of haploid sequences, and to produce a set of haploid consensus sequences rather than a single consensus sequence. Existing WGS assemblers take a column-by-column approach to consensus generation, and produce a single consensus sequence which can be inconsistent with the underlying haploid alleles, and inconsistent with any of the aligned sequence reads. Our new algorithm uses a dynamic windowing approach. It detects alleles by simultaneously processing the portions of aligned reads spanning a region of sequence variation, assigns reads to their respective alleles, phases adjacent variant alleles and generates a consensus sequence corresponding to each confirmed allele. This algorithm was used to produce the first diploid genome sequence of an individual human. It can also be applied to assemblies of multiple diploid individuals and hybrid assemblies of multiple haploid organisms.Being applied to the individual human genome assembly, the new algorithm detects exactly two confirmed alleles and reports two consensus sequences in 98.98% of the total number 2,033311 detected regions of sequence variation. In 33,269 out of 460,373 detected regions of size >1 bp, it fixes the constructed errors of a mosaic haploid representation of a diploid locus as produced by the original Celera Assembler consensus algorithm. Using an optimized procedure calibrated against 1 506 344 known SNPs, it detects 438 814 new heterozygous SNPs with false positive rate 12%.The open source code is available at: http://wgs-assembler.cvs.sourceforge.net/wgs-assembler/
Year
DOI
Venue
2008
10.1093/bioinformatics/btn074
Bioinformatics
Keywords
Field
DocType
sequence variation,original celera assembler consensus,haploid consensus,single consensus sequence,variant detection,diploid genome sequence,haploid sequence,consensus generation,new algorithm,mosaic haploid representation,consensus sequence,whole genome shotgun,genome sequence,human genome,false positive rate
Shotgun sequencing,Ploidy,Allele,Biology,Whole genome sequencing,Single-nucleotide polymorphism,Bioinformatics,Human genome,Locus (genetics),Consensus sequence
Journal
Volume
Issue
ISSN
24
8
1367-4811
Citations 
PageRank 
References 
9
1.71
9
Authors
7
Name
Order
Citations
PageRank
Gennady Denisov1425.44
Brian Walenz217214.84
Aaron L. Halpern35514.04
Jason R Miller4889.47
Nelson Axelrod5132.23
Samuel Levy6412.72
Granger Sutton78610.49