DECIPHER, a Search-Based Approach to Chimera Identification for ...

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Aug 11, 2011 - formed from closely related parents (less than 10% divergence). ..... In this algorithm, a trusted band of known nucleotides is defined for.
DECIPHER, a Search-Based Approach to Chimera Identification for 16S rRNA Sequences Erik S. Wright, L. Safak Yilmaz, and Daniel R. Noguera Department of Civil and Environmental Engineering, University of Wisconsin—Madison, Madison, Wisconsin, USA

DECIPHER is a new method for finding 16S rRNA chimeric sequences by the use of a search-based approach. The method is based upon detecting short fragments that are uncommon in the phylogenetic group where a query sequence is classified but frequently found in another phylogenetic group. The algorithm was calibrated for full sequences (fs_DECIPHER) and short sequences (ss_DECIPHER) and benchmarked against WigeoN (Pintail), ChimeraSlayer, and Uchime using artificially generated chimeras. Overall, ss_DECIPHER and Uchime provided the highest chimera detection for sequences 100 to 600 nucleotides long (79% and 81%, respectively), but Uchime’s performance deteriorated for longer sequences, while ss_DECIPHER maintained a high detection rate (89%). Both methods had low false-positive rates (1.3% and 1.6%). The more conservative fs_DECIPHER, benchmarked only for sequences longer than 600 nucleotides, had an overall detection rate lower than that of ss_DECIPHER (75%) but higher than those of the other programs. In addition, fs_DECIPHER had the lowest false-positive rate among all the benchmarked programs (

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