title: Using next-generation sequencing for molecular reconstruction of past Arctic vegetation and climate.
abstract: Palaeoenvironments and former climates are typically inferred from pollen and macrofossil records. This approach is time-consuming and suffers from low taxonomic resolution and biased taxon sampling. Here, we test an alternative DNA-based approach utilizing the P6 loop in the chloroplast trnL (UAA) intron; a short (13-158 bp) and variable region with highly conserved flanking sequences. For taxonomic reference, a whole trnL intron sequence database was constructed from recently collected material of 842 species, representing all widespread and/or ecologically important taxa of the species-poor arctic flora. The P6 loop alone allowed identification of all families, most genera (>75%) and one-third of the species, thus providing much higher taxonomic resolution than pollen records. The suitability of the P6 loop for analysis of samples containing degraded ancient DNA from a mixture of species is demonstrated by high-throughput parallel pyrosequencing of permafrost-preserved DNA and reconstruction of two plant communities from the last glacial period. Our approach opens new possibilities for DNA-based assessment of ancient as well as modern biodiversity of many groups of organisms using environmental samples.
authors.affiliation: National Centre for Biosystematics, Natural History Museum, University of Oslo, P.O.Box 1172 Blindern, NO-0318 Oslo, Norway.
authors.forename: J H
authors.initials: JH
authors.lastname: Sønstebø
authors.forename: L
authors.initials: L
authors.lastname: Gielly
authors.forename: A K
authors.initials: AK
authors.lastname: Brysting
authors.forename: R
authors.initials: R
authors.lastname: Elven
authors.forename: M
authors.initials: M
authors.lastname: Edwards
authors.forename: J
authors.initials: J
authors.lastname: Haile
authors.forename: E
authors.initials: E
authors.lastname: Willerslev
authors.forename: E
authors.initials: E
authors.lastname: Coissac
authors.forename: D
authors.initials: D
authors.lastname: Rioux
authors.forename: J
authors.initials: J
authors.lastname: Sannier
authors.forename: P
authors.initials: P
authors.lastname: Taberlet
authors.forename: C
authors.initials: C
authors.lastname: Brochmann