RADtools

RADtools processes Restriction site Associated DNA (RAD) sequencing data to convert Illumina reads into candidate genetic markers for single nucleotide polymorphism (SNP) discovery and genotyping in genetic mapping studies.

Key Features:

• High-Density SNP Discovery: Identifies large numbers of SNPs from RAD tags, with reports of over 13,000 SNPs detected using less than half of an Illumina sequencing run.
• Flexible Marker Density: Allows adjustment of marker density by selecting different restriction enzymes.
• Sample Multiplexing via Barcoding: Uses barcode-based sample multiplexing to demultiplex and assign Illumina reads to multiple samples.
• Trait Mapping and Fine Mapping: Maps traits and performs fine mapping by identifying recombinant breakpoints, demonstrated in threespine stickleback studies of lateral plate armor loss and pelvic structure reduction.
• In Silico Re-sorting: Performs in silico re-sorting of individuals to refine mapping analyses without additional experimental sampling.
• Application Across Diverse Organisms: Has been applied to organisms including threespine stickleback and Neurospora crassa for mapping induced mutations and other genetic studies.

Scientific Applications:

• High-throughput SNP discovery and genotyping: Generation of SNP datasets and genotype calls from RAD sequencing for mapping and population studies.
• Genetic mapping: Construction of genetic maps and identification of loci underlying traits via recombinant breakpoint detection.
• Evolutionary biology: Analysis of genetic variation and population structure using RAD-derived markers.
• Functional genomics: Mapping induced mutations and linking genotype to phenotype in experimental organisms such as Neurospora crassa.
• Population genetics: Assessment of allele frequencies, population differentiation, and genetic diversity using RAD-based SNPs.

Methodology:

Sequences RAD tags to generate SNP data, employs restriction enzymes to tune marker density, and integrates barcode-based sample multiplexing for demultiplexing Illumina reads.