@article{SchulteBernhardtStoofLeichsenringetal.2020,
  author    = {Schulte, Luise and Bernhardt, Nadine and Stoof-Leichsenring, Kathleen Rosemarie and Zimmermann, Heike Hildegard and Pestryakova, Luidmila Agafyevna and Epp, Laura S. and Herzschuh, Ulrike},
  title     = {Hybridization capture of larch (Larix Mill.) chloroplast genomes from sedimentary ancient DNA reveals past changes of Siberian forest},
  series = {Molecular ecology resources},
  volume    = {21},
  journal   = {Molecular ecology resources},
  number    = {3},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1755-098X},
  doi       = {10.1111/1755-0998.13311},
  pages     = {801 -- 815},
  year      = {2020},
  abstract  = {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.},
  language  = {en}
}
@article{KruegerFoersterTrauthetal.2021,
  author    = {Kr{\"u}ger, Johanna and Foerster, Verena Elisabeth and Trauth, Martin H. and Hofreiter, Michael and Tiedemann, Ralph},
  title     = {Exploring the Past Biosphere of Chew Bahir/Southern Ethiopia: Cross-Species Hybridization Capture of Ancient Sedimentary DNA from a Deep Drill Core},
  series = {Frontiers in Earth Science},
  journal   = {Frontiers in Earth Science},
  publisher = {Frontiers in Earth Science},
  address   = {Lausanne, Schweiz},
  issn      = {2296-6463},
  doi       = {10.3389/feart.2021.683010},
  pages     = {1 -- 20},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}