title: Temporal fluctuation in North East Baltic Sea region cattle population revealed by mitochondrial and Y-chromosomal DNA analyses.
abstract: BACKGROUND
  Ancient DNA analysis offers a way to detect changes in populations over time. To date, most studies of ancient cattle have focused on their domestication in prehistory, while only a limited number of studies have analysed later periods. Conversely, the genetic structure of modern cattle populations is well known given the undertaking of several molecular and population genetic studies.
  
  
  RESULTS
  Bones and teeth from ancient cattle populations from the North-East Baltic Sea region dated to the Prehistoric (Late Bronze and Iron Age, 5 samples), Medieval (14), and Post-Medieval (26) periods were investigated by sequencing 667 base pairs (bp) from the mitochondrial DNA (mtDNA) and 155 bp of intron 19 in the Y-chromosomal UTY gene. Comparison of maternal (mtDNA haplotypes) genetic diversity in ancient cattle (45 samples) with modern cattle populations in Europe and Asia (2094 samples) revealed 30 ancient mtDNA haplotypes, 24 of which were shared with modern breeds, while 6 were unique to the ancient samples. Of seven Y-chromosomal sequences determined from ancient samples, six were Y2 and one Y1 haplotype. Combined data including Swedish samples from the same periods (64 samples) was compared with the occurrence of Y-chromosomal haplotypes in modern cattle (1614 samples).
  
  
  CONCLUSIONS
  The diversity of haplogroups was highest in the Prehistoric samples, where many haplotypes were unique. The Medieval and Post-Medieval samples also show a high diversity with new haplotypes. Some of these haplotypes have become frequent in modern breeds in the Nordic Countries and North-Western Russia while other haplotypes have remained in only a few local breeds or seem to have been lost. A temporal shift in Y-chromosomal haplotypes from Y2 to Y1 was detected that corresponds with the appearance of new mtDNA haplotypes in the Medieval and Post-Medieval period. This suggests a replacement of the Prehistoric mtDNA and Y chromosomal haplotypes by new types of cattle.
authors.affiliation: Biotechnology and Food Research, MTT Agrifood Research Finland, Jokioinen, Finland; University of Helsinki, Department of Forensic Medicine, Helsinki, Finland.
authors.forename: Marianna
authors.initials: M
authors.lastname: Niemi
authors.affiliation: Biotechnology and Food Research, MTT Agrifood Research Finland, Jokioinen, Finland; Department of Archaeology, University of Turku, Turku, Finland.
authors.forename: Auli
authors.initials: A
authors.lastname: Bläuer
authors.affiliation: Biotechnology and Food Research, MTT Agrifood Research Finland, Jokioinen, Finland.
authors.forename: Terhi
authors.initials: T
authors.lastname: Iso-Touru
authors.affiliation: Biotechnology and Food Research, MTT Agrifood Research Finland, Jokioinen, Finland; Department of Archaeology, University of Turku, Turku, Finland.
authors.forename: Janne
authors.initials: J
authors.lastname: Harjula
authors.affiliation: Department of Zoology, Stockholm University, Stockholm, Sweden.
authors.forename: Veronica
authors.initials: V
authors.lastname: Nyström Edmark
authors.affiliation: Institute of History and Archaeology, University of Tartu, Tartu, Estonia.
authors.forename: Eve
authors.initials: E
authors.lastname: Rannamäe
authors.affiliation: Institute of history, Tallinn University, Tallinn, Estonia.
authors.forename: Lembi
authors.initials: L
authors.lastname: Lõugas
authors.affiliation: University of Helsinki, Department of Forensic Medicine, Helsinki, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Sajantila
authors.affiliation: Archaeological Research Laboratory, Stockholm University, Stockholm, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Lidén
authors.affiliation: Department of Archaeology, University of Turku, Turku, Finland.
authors.forename: Jussi-Pekka
authors.initials: JP
authors.lastname: Taavitsainen
mesh_terms: D000818:Animals; D000829:Animals, Domestic / Q000235:genetics; D001454:Baltic States; D001483:Base Sequence; D001842:Bone and Bones / Q000166:cytology; D001947:Breeding; D002417:Cattle / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics; D008928:Mitochondria / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D055110:Radiometric Dating; D017422:Sequence Analysis, DNA / Q000662:veterinary; D014998:Y Chromosome / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial