June 29 (UPI) -- Analysis of the Y chromosomes of 50 horses, comprising 21 breeds, suggests almost all modern horses are descended from Oriental stallions brought to Europe during the last 700 years.
"Apart from stallion lines in Northern European breeds, all stallion lines detected in other modern breeds derive from more recently introduced Oriental ancestors," Barbara Wallner, a researcher with the University of Veterinary Medicine, Vienna, said in a news release. "Our data therefore illuminate the enormous impact modern horse breeding strategies -- characterized by strong selection of males and the import of Oriental stallions -- during the past few hundred years had on Y chromosome diversity."
Y chromosomes reveal the genes inherited along paternal lineages -- DNA passed from father to son. As random genetic mutations accumulate over time, these mutations are passed along the male lineage. This trail of mutations can help scientists identify the ancestral origin of a modern male horse.
"Males who originate from a common patrilineal ancestor will share a particular collection of Y chromosome mutations," Wallner said.
There is very little genetic diversity to be found among the Y chromosomes of modern horses, but improved genetic sequencing technologies has made it possible to identify even the tiniest of mutations.
Horses were first domesticated some 5,000 years ago. But the latest genetic analysis, detailed this week in the journal Current Biology, suggests most modern breeds diverged from their wild relatives just 700 years ago.
The haplogroup of Oriental stallions -- from which most modern breeds descend from -- can be divided into two clades: the Original Arabian lineage from the Arabian Peninsula and the Turkoman lineage from the Central Asian steppes.
Researchers were able to use the new genetic data, as well as written historical records, to trace the origins of English Thoroughbreds to founder stallions from the Turkoman lineage.
"Our results pave the way for a fine-scaled genetic characterization of stallion lines, which should become routine in the near future," Wallner said.