Evolutionary Genomics and Conservation of the Endangered Przewalski's Horse.

DOI
Publisher DOI
PubMed ID
26412128
Abstract
Przewalski's horses (PHs, Equus ferus ssp. przewalskii) were discovered in the Asian steppes in the 1870s and represent the last remaining true wild horses. PHs became extinct in the wild in the 1960s but survived in captivity, thanks to major conservation efforts. The current population is still endangered, with just 2,109 individuals, one-quarter of which are in Chinese and Mongolian reintroduction reserves [1]. These horses descend from a founding population of 12 wild-caught PHs and possibly up to four domesticated individuals [2-4]. With a stocky build, an erect mane, and stripped and short legs, they are phenotypically and behaviorally distinct from domesticated horses (DHs, Equus caballus). Here, we sequenced the complete genomes of 11 PHs, representing all founding lineages, and five historical specimens dated to 1878-1929 CE, including the Holotype. These were compared to the hitherto-most-extensive genome dataset characterized for horses, comprising 21 new genomes. We found that loci showing the most genetic differentiation with DHs were enriched in genes involved in metabolism, cardiac disorders, muscle contraction, reproduction, behavior, and signaling pathways. We also show that DH and PH populations split ∼45,000 years ago and have remained connected by gene-flow thereafter. Finally, we monitor the genomic impact of ∼110 years of captivity, revealing reduced heterozygosity, increased inbreeding, and variable introgression of domestic alleles, ranging from non-detectable to as much as 31.1%. This, together with the identification of ancestry informative markers and corrections to the International Studbook, establishes a framework for evaluating the persistence of genetic variation in future reintroduced populations.
Date Issued
2015-10-05
Publication Type
Article
Subject(s)
Language(s)
en
Author(s)
Der Sarkissian, Clio
Ermini, Luca
Schubert, Mikkel
Yang, Melinda A
Librado, Pablo
Fumagalli, Matteo
Jónsson, Hákon
Bar-Gal, Gila Kahila
Albrechtsen, Anders
Vieira, Filipe G
Petersen, Bent
Ginolhac, Aurélien
Seguin-Orlando, Andaine
Magnussen, Kim
Fages, Antoine
Gamba, Cristina
Lorente-Galdos, Belen
Polani, Sagi
Steiner, Cynthia
Neuditschko, Markus
Feh, Claudia
Greenblatt, Charles L
Ludwig, Arne
Abramson, Natalia I
Zimmermann, Waltraut
Schafberg, Renate
Tikhonov, Alexei
Sicheritz-Ponten, Thomas
Willerslev, Eske
Marques-Bonet, Tomas
Ryder, Oliver A
McCue, Molly
Rieder, Stefan
Slatkin, Montgomery
Orlando, Ludovic
Additional Credits
Journal
Current Biology
Publisher
Cell Press
ISSN
0960-9822
Access(Rights)
restricted
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