ChimeraSlayer

ChimeraSlayer detects chimeric sequences in 16S ribosomal RNA (rRNA) gene datasets to prevent overestimation of microbial diversity and erroneous taxonomic assignments.

Key Features:

• High Sensitivity: Offers high sensitivity in detecting chimeric 16S rRNA sequences, identifying chimeras that other methods may miss.
• Compatibility with Short Sequences: Operates effectively on short sequence reads, including reads generated by the 454 Life Sciences (Roche) Genome Sequencer.
• Scalability: Processes large, high-throughput 16S rRNA datasets to support extensive microbial community analyses.
• Integration with NAST-iEr Utility: Requires NAST-formatted sequences generated with the included NAST-iEr utility for compatibility with the ChimeraSlayer workflow.

Scientific Applications:

• Microbial diversity assessment: Removes chimeric artifacts from 16S rRNA gene datasets to improve accuracy of bacterial diversity estimates and taxonomic identification.
• Chimera prevalence analysis: Enables analysis of factors influencing chimera formation, with studies reporting that less-abundant species can exhibit chimera rates exceeding 70% under certain conditions.
• Validation of novel taxa: Supports comparison with shotgun metagenomic sequencing of mock communities, which showed an absence of 16S rRNA gene chimeras and can serve to validate taxa identified in targeted surveys.

Methodology:

Benchmarking was performed against controlled DNA mixtures of known organisms and simulated chimeric sequences, and analyses identified factors influencing chimera formation including sequence abundance, degree of similarity between 16S genes, and PCR conditions.