MOTIVATION: 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. RESULTS: 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%. AVAILABILITY: The open source code is available at: http://wgs-assembler.cvs.sourceforge.net/wgs-assembler/
MOTIVATION: 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. RESULTS: 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%. AVAILABILITY: The open source code is available at: http://wgs-assembler.cvs.sourceforge.net/wgs-assembler/
Authors: Shawn T O'Neil; Jason D K Dzurisin; Rory D Carmichael; Neil F Lobo; Scott J Emrich; Jessica J Hellmann Journal: BMC Genomics Date: 2010-05-17 Impact factor: 3.969
Authors: Rami A Dalloul; Julie A Long; Aleksey V Zimin; Luqman Aslam; Kathryn Beal; Le Ann Blomberg; Pascal Bouffard; David W Burt; Oswald Crasta; Richard P M A Crooijmans; Kristal Cooper; Roger A Coulombe; Supriyo De; Mary E Delany; Jerry B Dodgson; Jennifer J Dong; Clive Evans; Karin M Frederickson; Paul Flicek; Liliana Florea; Otto Folkerts; Martien A M Groenen; Tim T Harkins; Javier Herrero; Steve Hoffmann; Hendrik-Jan Megens; Andrew Jiang; Pieter de Jong; Pete Kaiser; Heebal Kim; Kyu-Won Kim; Sungwon Kim; David Langenberger; Mi-Kyung Lee; Taeheon Lee; Shrinivasrao Mane; Guillaume Marcais; Manja Marz; Audrey P McElroy; Thero Modise; Mikhail Nefedov; Cédric Notredame; Ian R Paton; William S Payne; Geo Pertea; Dennis Prickett; Daniela Puiu; Dan Qioa; Emanuele Raineri; Magali Ruffier; Steven L Salzberg; Michael C Schatz; Chantel Scheuring; Carl J Schmidt; Steven Schroeder; Stephen M J Searle; Edward J Smith; Jacqueline Smith; Tad S Sonstegard; Peter F Stadler; Hakim Tafer; Zhijian Jake Tu; Curtis P Van Tassell; Albert J Vilella; Kelly P Williams; James A Yorke; Liqing Zhang; Hong-Bin Zhang; Xiaojun Zhang; Yang Zhang; Kent M Reed Journal: PLoS Biol Date: 2010-09-07 Impact factor: 8.029