Case study: enrichment of ancient mitochondrial DNA by hybridization capture

In ancient DNA studies focusing on estimating population histories, genetic markers are sequenced from a large number of samples belonging to the same species. Targeting loci of interest using traditional PCR can be time-consuming, in particular when samples are not well preserved and multiple overlapping fragments are required. Here, I describe the process of generating DNA libraries from ancient DNA (aDNA) extracts for high-throughput sequencing. I use a serial in-solution DNA hybridization approach with subsequent bead capture to enrich libraries for the target locus, in this case the mitochondrial control region of ancient beavers (Castor fiber). The resulting sequencing reads are run through quality control filters to obtain reliable consensus sequences. Using these sequences, I construct a phylogenetic tree, which agrees with previously published data regarding phylogeographic relationships among beavers.