TY - JOUR A1 - Schulte, Luise A1 - Bernhardt, Nadine A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Zimmermann, Heike Hildegard A1 - Pestryakova, Luidmila Agafyevna A1 - Epp, Laura S. A1 - Herzschuh, Ulrike T1 - Hybridization capture of larch (Larix Mill.) chloroplast genomes from sedimentary ancient DNA reveals past changes of Siberian forest JF - Molecular ecology resources N2 - Siberian larch (Larix Mill.) forests dominate vast areas of northern Russia and contribute important ecosystem services to the world. It is important to understand the past dynamics of larches in order to predict their likely response to a changing climate in the future. Sedimentary ancient DNA extracted from lake sediment cores can serve as archives to study past vegetation. However, the traditional method of studying sedimentary ancient DNA-metabarcoding-focuses on small fragments, which cannot resolve Larix to species level nor allow a detailed study of population dynamics. Here, we use shotgun sequencing and hybridization capture with long-range PCR-generated baits covering the complete Larix chloroplast genome to study Larix populations from a sediment core reaching back to 6700 years from the Taymyr region in northern Siberia. In comparison with shotgun sequencing, hybridization capture results in an increase in taxonomically classified reads by several orders of magnitude and the recovery of complete chloroplast genomes of Larix. Variation in the chloroplast reads corroborates an invasion of Larix gmelinii into the range of Larix sibirica before 6700 years ago. Since then, both species have been present at the site, although larch populations have decreased with only a few trees remaining in what was once a forested area. This study demonstrates for the first time that hybridization capture applied directly to ancient DNA of plants extracted from lake sediments can provide genome-scale information and is a viable tool for studying past genomic changes in populations of single species, irrespective of a preservation as macrofossil. KW - chloroplast genome KW - hybridization capture KW - Larix KW - sediment core KW - sedimentary ancient DNA KW - target enrichment Y1 - 2020 U6 - https://doi.org/10.1111/1755-0998.13311 SN - 1755-098X SN - 1755-0998 VL - 21 IS - 3 SP - 801 EP - 815 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Krüger, Johanna A1 - Foerster, Verena Elisabeth A1 - Trauth, Martin H. A1 - Hofreiter, Michael A1 - Tiedemann, Ralph T1 - Exploring the Past Biosphere of Chew Bahir/Southern Ethiopia: Cross-Species Hybridization Capture of Ancient Sedimentary DNA from a Deep Drill Core JF - Frontiers in Earth Science N2 - Eastern Africa has been a prime target for scientific drilling because it is rich in key paleoanthropological sites as well as in paleolakes, containing valuable paleoclimatic information on evolutionary time scales. The Hominin Sites and Paleolakes Drilling Project (HSPDP) explores these paleolakes with the aim of reconstructing environmental conditions around critical episodes of hominin evolution. Identification of biological taxa based on their sedimentary ancient DNA (sedaDNA) traces can contribute to understand past ecological and climatological conditions of the living environment of our ancestors. However, sedaDNA recovery from tropical environments is challenging because high temperatures, UV irradiation, and desiccation result in highly degraded DNA. Consequently, most of the DNA fragments in tropical sediments are too short for PCR amplification. We analyzed sedaDNA in the upper 70 m of the composite sediment core of the HSPDP drill site at Chew Bahir for eukaryotic remnants. We first tested shotgun high throughput sequencing which leads to metagenomes dominated by bacterial DNA of the deep biosphere, while only a small fraction was derived from eukaryotic, and thus probably ancient, DNA. Subsequently, we performed cross-species hybridization capture of sedaDNA to enrich ancient DNA (aDNA) from eukaryotic remnants for paleoenvironmental analysis, using established barcoding genes (cox1 and rbcL for animals and plants, respectively) from 199 species that may have had relatives in the past biosphere at Chew Bahir. Metagenomes yielded after hybridization capture are richer in reads with similarity to cox1 and rbcL in comparison to metagenomes without prior hybridization capture. Taxonomic assignments of the reads from these hybridization capture metagenomes also yielded larger fractions of the eukaryotic domain. For reads assigned to cox1, inferred wet periods were associated with high inferred relative abundances of putative limnic organisms (gastropods, green algae), while inferred dry periods showed increased relative abundances for insects. These findings indicate that cross-species hybridization capture can be an effective approach to enhance the information content of sedaDNA in order to explore biosphere changes associated with past environmental conditions, enabling such analyses even under tropical conditions. KW - Chew Bahir KW - hybridization capture KW - ICDP KW - paleoclimate KW - past biosphere KW - sedaDNA KW - sediment core Y1 - 2021 U6 - https://doi.org/10.3389/feart.2021.683010 SN - 2296-6463 SP - 1 EP - 20 PB - Frontiers in Earth Science CY - Lausanne, Schweiz ER - TY - JOUR A1 - Förster, Daniel W. A1 - Bull, James K. A1 - Lenz, Dorina A1 - Autenrieth, Marijke A1 - Paijmans, Johanna L. A. A1 - Kraus, Robert H. S. A1 - Nowak, Carsten A1 - Bayerl, Helmut A1 - Kühn, Ralph A1 - Saveljev, Alexander P. A1 - Sindicic, Magda A1 - Hofreiter, Michael A1 - Schmidt, Krzysztof A1 - Fickel, Jörns T1 - Targeted resequencing of coding DNA sequences for SNP discovery in nonmodel species JF - Molecular ecology resources N2 - Targeted capture coupled with high-throughput sequencing can be used to gain information about nuclear sequence variation at hundreds to thousands of loci. Divergent reference capture makes use of molecular data of one species to enrich target loci in other (related) species. This is particularly valuable for nonmodel organisms, for which often no a priori knowledge exists regarding these loci. Here, we have used targeted capture to obtain data for 809 nuclear coding DNA sequences (CDS) in a nonmodel organism, the Eurasian lynx Lynx lynx, using baits designed with the help of the published genome of a related model organism (the domestic cat Felis catus). Using this approach, we were able to survey intraspecific variation at hundreds of nuclear loci in L. lynx across the species’ European range. A large set of biallelic candidate SNPs was then evaluated using a high-throughput SNP genotyping platform (Fluidigm), which we then reduced to a final 96 SNP-panel based on assay performance and reliability; validation was carried out with 100 additional Eurasian lynx samples not included in the SNP discovery phase. The 96 SNP-panel developed from CDS performed very successfully in the identification of individuals and in population genetic structure inference (including the assignment of individuals to their source population). In keeping with recent studies, our results show that genic SNPs can be valuable for genetic monitoring of wildlife species. KW - CDS KW - conservation genetics KW - Eurasian lynx KW - genetic monitoring KW - hybridization capture KW - single nucleotide polymorphism Y1 - 2018 U6 - https://doi.org/10.1111/1755-0998.12924 SN - 1755-098X SN - 1755-0998 VL - 18 IS - 6 SP - 1356 EP - 1373 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Paijmans, Johanna L. A. A1 - Fickel, Jörns A1 - Courtiol, Alexandre A1 - Hofreiter, Michael A1 - Foerster, Daniel W. T1 - Impact of enrichment conditions on cross-species capture of fresh and degraded DNA JF - Molecular ecology resources N2 - Abstract By combining high-throughput sequencing with target enrichment (‘hybridization capture’), researchers are able to obtain molecular data from genomic regions of interest for projects that are otherwise constrained by sample quality (e.g. degraded and contamination-rich samples) or a lack of a priori sequence information (e.g. studies on nonmodel species). Despite the use of hybridization capture in various fields of research for many years, the impact of enrichment conditions on capture success is not yet thoroughly understood. We evaluated the impact of a key parameter – hybridization temperature – on the capture success of mitochondrial genomes across the carnivoran family Felidae. Capture was carried out for a range of sample types (fresh, archival, ancient) with varying levels of sequence divergence between bait and target (i.e. across a range of species) using pools of individually indexed libraries on Agilent SureSelect™ arrays. Our results suggest that hybridization capture protocols require specific optimization for the sample type that is being investigated. Hybridization temperature affected the proportion of on-target sequences following capture: for degraded samples, we obtained the best results with a hybridization temperature of 65 °C, while a touchdown approach (65 °C down to 50 °C) yielded the best results for fresh samples. Evaluation of capture performance at a regional scale (sliding window approach) revealed no significant improvement in the recovery of DNA fragments with high sequence divergence from the bait at any of the tested hybridization temperatures, suggesting that hybridization temperature may not be the critical parameter for the enrichment of divergent fragments. KW - degraded DNA KW - Felidae KW - hybridization capture KW - mitogenomes KW - next-generation sequencing KW - sequence enrichment Y1 - 2016 U6 - https://doi.org/10.1111/1755-0998.12420 SN - 1755-098X SN - 1755-0998 VL - 16 SP - 42 EP - 55 PB - Wiley-Blackwell CY - Hoboken ER -