The future is now: Amplicon sequencing and sequence capture usher in the conservation genomics era

TLDR

The genomics revolution has ushered in a new era of population genetics, yet its application to conservation remains limited; recent amplicon sequencing and sequence capture methods promise to advance conservation genomics. The authors aim to compare amplicon sequencing and sequence capture, offering a decision framework for geneticists integrating these methods. Amplicon sequencing uses highly multiplexed PCR followed by high-throughput sequencing (e.g., GTseq), while sequence capture employs probe-based isolation of loci from reduced-representation libraries (e.g., Rapture), both enabling low-cost, large-scale sequencing without specialized equipment or advanced computational needs. Amplicon sequencing is best for projects genotyping fewer than 500 loci across many individuals (>1,500) or for ongoing monitoring, whereas sequence capture suits projects with fewer individuals or requiring more than 500 loci, and both methods facilitate the shift toward conservation genomics.

Abstract

The genomics revolution has initiated a new era of population genetics where genome-wide data are frequently used to understand complex patterns of population structure and selection. However, the application of genomic tools to inform management and conservation has been somewhat rare outside a few well studied species. Fortunately, two recently developed approaches, amplicon sequencing and sequence capture, have the potential to significantly advance the field of conservation genomics. Here, amplicon sequencing refers to highly multiplexed PCR followed by high-throughput sequencing (e.g., GTseq), and sequence capture refers to using capture probes to isolate loci from reduced-representation libraries (e.g., Rapture). Both approaches allow sequencing of thousands of individuals at relatively low costs, do not require any specialized equipment for library preparation, and generate data that can be analyzed without sophisticated computational infrastructure. Here, we discuss the advantages and disadvantages of each method and provide a decision framework for geneticists who are looking to integrate these methods into their research programme. While it will always be important to consider the specifics of the biological question and system, we believe that amplicon sequencing is best suited for projects aiming to genotype <500 loci on many individuals (>1,500) or for species where continued monitoring is anticipated (e.g., long-term pedigrees). Sequence capture, on the other hand, is best applied to projects including fewer individuals or where >500 loci are required. Both of these techniques should smooth the transition from traditional genetic techniques to genomics, helping to usher in the conservation genomics era.