title: Tracing the first steps of American sturgeon pioneers in Europe.
abstract: BACKGROUND
  A Baltic population of Atlantic sturgeon was founded approximately 1,200 years ago by migrants from North America, but after centuries of persistence, the population was extirpated in the 1960s, mainly as a result of over-harvest and habitat alterations. As there are four genetically distinct groups of Atlantic sturgeon inhabiting North American rivers today, we investigated the genetic provenance of the historic Baltic population by ancient DNA analyses using mitochondrial and nuclear markers.
  
  
  RESULTS
  The phylogeographic signal obtained from multilocus microsatellite DNA genotypes and mitochondrial DNA control region haplotypes, when compared to existing baseline datasets from extant populations, allowed for the identification of the region-of-origin of the North American Atlantic sturgeon founders. Moreover, statistical and simulation analyses of the multilocus genotypes allowed for the calculation of the effective number of individuals that originally founded the European population of Atlantic sturgeon. Our findings suggest that the Baltic population of A. oxyrinchus descended from a relatively small number of founders originating from the northern extent of the species' range in North America.
  
  
  CONCLUSIONS
  These results demonstrate that the most northerly distributed North American A. oxyrinchus colonized the Baltic Sea approximately 1,200 years ago, suggesting that Canadian specimens should be the primary source of broodstock used for restoration in Baltic rivers. This study illustrates the great potential of patterns obtained from ancient DNA to identify population-of-origin to investigate historic genotype structure of extinct populations.
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Evolutionary Genetics, 12561 Berlin, Germany. ludwig@izw-berlin.de
authors.forename: Arne
authors.initials: A
authors.lastname: Ludwig
authors.forename: Ursula
authors.initials: U
authors.lastname: Arndt
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lippold
authors.forename: Norbert
authors.initials: N
authors.lastname: Benecke
authors.forename: Lutz
authors.initials: L
authors.lastname: Debus
authors.forename: Timothy L
authors.initials: TL
authors.lastname: King
authors.forename: Shuichi
authors.initials: S
authors.lastname: Matsumura
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D001483:Base Sequence; D002678:Chimera / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D005060:Europe; D019143:Evolution, Molecular; D005399:Fishes / Q000235:genetics*; D005828:Genetics, Population; D006239:Haplotypes; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial