标题：Origin and History of Mitochondrial DNA Lineages inDomestic Horses
摘要：Domestic horses represent a genetic paradox: although they have the greatest number of maternal lineages (mtDNA) of alldomestic species, their paternal lineages are extremely homogeneous on the Y-chromosome. In order to address their hugemtDNA variation and the origin and history of maternal lineages in domestic horses, we analyzed 1961 partial d-loopsequences from 207 ancient remains and 1754 modern horses. The sample set ranged from Alaska and North East Siberia tothe Iberian Peninsula and from the Late Pleistocene to modern times. We found a panmictic Late Pleistocene horsepopulation ranging from Alaska to the Pyrenees. Later, during the Early Holocene and the Copper Age, more or lessseparated sub-populations are indicated for the Eurasian steppe region and Iberia. Our data suggest multipledomestications and introgressions of females especially during the Iron Age. Although all Eurasian regions contributedto the genetic pedigree of modern breeds, most haplotypes had their roots in Eastern Europe and Siberia. We found 87ancient haplotypes (Pleistocene to Mediaeval Times); 56 of these haplotypes were also observed in domestic horses,although thus far only 39 haplotypes have been confirmed to survive in modern breeds. Thus, at least seventeen haplotypesof early domestic horses have become extinct during the last 5,500 years. It is concluded that the large diversity of mtDNAlineages is not a product of animal breeding but, in fact, represents ancestral variability.