PriSeT

PriSeT identifies de novo PCR primer candidates for DNA metabarcoding experiments to maximize taxonomic coverage and barcode discriminatory power when profiling complex environmental samples.

Key Features:

• Taxonomic coverage optimization: Identifies conserved regions flanking variable barcode segments to provide candidate primer binding sites that enable amplification across broad evolutionary ranges while minimizing the number of primer sets.
• Resolution enhancement: Targets variable barcode regions bounded by conserved primer sites and balances primer frequency and barcode variation to improve species-level discrimination.
• Robustness to reference data quality issues: Designed to be resilient to mislabeled or low-quality reference sequences, supporting primer discovery from large reference libraries without disproportionate sensitivity to noise.
• Efficient computational performance: Applies linear-time filters and compact encodings to reduce computational overhead for rapid processing of extensive datasets.

Scientific Applications:

• Environmental DNA metabarcoding: Supports primer design for inferring community composition from environmental samples, enabling identification of large numbers of organisms spanning closely and distantly related taxa.
• Freshwater plankton studies: Evaluated on reference libraries dominated by freshwater eukaryotes and can propose primer sets with improved taxon coverage and barcode variability relative to published alternatives.
• Viral genomics (e.g., SARS-CoV-2): Applicable to viral sequence collections and demonstrated for designing primer pairs under constraints such as avoiding primer co-occurrence in non-target taxa.

Methodology:

Frames primer discovery as an optimization problem balancing taxonomic coverage and barcode resolution, filters candidate primers based on frequency and chemical suitability, ranks and selects primer sets using coverage- and/or variation-based metrics, and employs linear-time filters with compact encodings to reduce computational overhead.