August 23, 2011

Ancient wild horse Y chromosomes more diverse than those of domesticated horses

The sequenced horses can be found in the supplement, and they all seem to be from Alaska/Yukon/Siberia, probably for reasons having to with DNA preservation.

Hopefully techniques will improve, and the study of ancient wild horse DNA may help identify the wild progenitors of domestic horses, which must have lived in the more western parts of Eurasia, rather than in the studied regions.

With domesticated crops we have been fortunate in still having access to their wild relatives, but wild horses are now all extinct, except Przewalski's horse, which, as as other research has also shown was not the progenitor of domesticated horses.

See also the press release.

Nature Communications 2, Article number: 450 doi:10.1038/ncomms1447

Discovery of lost diversity of paternal horse lineages using ancient DNA

Sebastian Lippold et al.


Modern domestic horses display abundant genetic diversity within female-inherited mitochondrial DNA, but practically no sequence diversity on the male-inherited Y chromosome. Several hypotheses have been proposed to explain this discrepancy, but can only be tested through knowledge of the diversity in both the ancestral (pre-domestication) maternal and paternal lineages. As wild horses are practically extinct, ancient DNA studies offer the only means to assess this ancestral diversity. Here we show considerable ancestral diversity in ancient male horses by sequencing 4 kb of Y chromosomal DNA from eight ancient wild horses and one 2,800-year-old domesticated horse. Both ancient and modern domestic horses form a separate branch from the ancient wild horses, with the Przewalski horse at its base. Our methodology establishes the feasibility of re-sequencing long ancient nuclear DNA fragments and demonstrates the power of ancient Y chromosome DNA sequence data to provide insights into the evolutionary history of populations.


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