Less is more: extreme genome complexity reduction with ddRAD using Ion Torrent semiconductor technology

Area of Science:

• Genomics
• Molecular Evolution
• Population Genetics

Background:

• Massively parallel sequencing of reduced genomic representation is crucial for diverse biological questions.
• Restriction-site associated DNA (RAD) sequencing is a powerful technique for genetic analysis.

Purpose of the Study:

• To develop and validate a double digest RAD (ddRAD) sequencing protocol for the Ion Torrent PGM platform.
• To generate genomic resources and identify genetic variations in the Eurasian perch (Perca fluviatilis L.).

Main Methods:

• Utilized a ddRAD sequencing approach with rare-cutting restriction enzymes and strict size selection for extreme genome complexity reduction.
• Applied the protocol to Eurasian perch, generating over 2.2 MB of sequence data and ~17,000 contigs.
• Identified 1259 single nucleotide polymorphisms (SNPs) and estimated genetic differentiation between freshwater and brackish water populations.

Main Results:

• Successfully generated substantial novel sequence data and identified a significant number of SNPs in the Eurasian perch.
• Estimated genetic differentiation between distinct populations, highlighting potential markers for individual assignment.
• Demonstrated the utility of the ddRAD protocol for generating high-depth sequencing data on a semiconductor platform.

Conclusions:

• The developed ddRAD sequencing protocol is an effective method for generating genomic resources and genetic markers in non-model organisms like the Eurasian perch.
• This protocol offers a valuable alternative to existing RAD sequencing methods, particularly for semiconductor sequencing technologies.
• The identified SNPs provide a foundation for future population genetics studies and conservation efforts for the Eurasian perch.