Identifying Conserved Genomic Elements and Designing Universal Probe Sets To Enrich Them

Abstract

Targeted enrichment of conserved genomic regions is a popular method for collecting large amounts of sequence data from non-model taxa for phylogenetic, phylogeographic, and population genetic studies. Yet, few open-source workflows are available to identify conserved genomic elements shared among divergent taxa and to design enrichment baits targeting these regions. These shortcomings limit the application of targeted enrichment methods to many organismal groups. Here, I describe a universal workflow for identifying conserved genomic regions in available genomic data and for designing targeted enrichment baits to collect data from these conserved regions. I demonstrate how this computational approach can be applied to diverse organismal groups by identifying sets of conserved loci and designing enrichment baits targeting thousands of these loci in the understudied arthropod groups Arachnida, Coleoptera, Diptera, Hemiptera, or Lepidoptera. I then use in silico analyses to demonstrate that these conserved loci reconstruct the accepted relationships among genome sequences from the focal arthropod orders, and we perform in vitro validation of the Arachnid probe set as part of a separate manuscript (Starrett et al. Submitted). All of the documentation, design steps, software code, and probe sets developed here are available under an open-source license for restriction-free testing and use by any research group, and although the examples in this manuscript focus on understudied and exceptionally diverse arthropod groups, the software workflow is applicable to all organismal groups having some form of pre-existing genomic information.