TY - JOUR
T1 - Whole genome sequencing reveals a complex introgression history and the basis of adaptation to subarctic climate in wild sheep
AU - Upadhyay, Maulik
AU - Kunz, Elisabeth
AU - Sandoval-Castellanos, Edson
AU - Hauser, Andreas
AU - Krebs, Stefan
AU - Graf, Alexander
AU - Blum, Helmut
AU - Dotsev, Arsen
AU - Okhlopkov, Innokentiy
AU - Shakhin, Alexey
AU - Bagirov, Vugar
AU - Brem, Gottfried
AU - Fries, Ruedi
AU - Zinovieva, Natalia
AU - Medugorac, Ivica
N1 - Publisher Copyright:
© 2021 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.
PY - 2021/12
Y1 - 2021/12
N2 - To predict species responses to anthropogenic disturbances and climate change, it is reasonable to use species with high sensitivity to such factors. Snow sheep (Ovis nivicola) could represent a good candidate for this; as the only large herbivore species adapted to the cold and alpine habitats of northeastern Siberia, it plays a crucial role in its ecosystem. Despite having an extensive geographical distribution among all ovine species, it is one of the least studied. In this study, we sequenced and analysed six genomes of snow sheep in combination with all other wild sheep species to infer key aspects of their evolutionary history and unveil the genetic basis of their adaptation to subarctic environments. Despite their large census population size, snow sheep genomes showed remarkably low heterozygosity, which could reflect the effect of isolation and historical bottlenecks that we inferred using the pairwise sequential Markovian coalescent and runs of homozygosity. F4-statistics indicated instances of introgression involving snow sheep with argali (Ovis ammon) and Dall (Ovis dalli) sheep, suggesting that these species might have been more widespread during the Pleistocene. Furthermore, the introgressed segments, which were identified using mainly minimum relative node depth, covered genes associated with immunity, adipogenesis and morphology-related traits, representing potential targets of adaptive introgression. Genes related to mitochondrial functions and thermogenesis associated with adipose tissue were identified to be under selection. Overall, our data suggest introgression as a mechanism facilitating adaptation in wild sheep species and provide insights into the genetic mechanisms underlying cold adaptation in snow sheep.
AB - To predict species responses to anthropogenic disturbances and climate change, it is reasonable to use species with high sensitivity to such factors. Snow sheep (Ovis nivicola) could represent a good candidate for this; as the only large herbivore species adapted to the cold and alpine habitats of northeastern Siberia, it plays a crucial role in its ecosystem. Despite having an extensive geographical distribution among all ovine species, it is one of the least studied. In this study, we sequenced and analysed six genomes of snow sheep in combination with all other wild sheep species to infer key aspects of their evolutionary history and unveil the genetic basis of their adaptation to subarctic environments. Despite their large census population size, snow sheep genomes showed remarkably low heterozygosity, which could reflect the effect of isolation and historical bottlenecks that we inferred using the pairwise sequential Markovian coalescent and runs of homozygosity. F4-statistics indicated instances of introgression involving snow sheep with argali (Ovis ammon) and Dall (Ovis dalli) sheep, suggesting that these species might have been more widespread during the Pleistocene. Furthermore, the introgressed segments, which were identified using mainly minimum relative node depth, covered genes associated with immunity, adipogenesis and morphology-related traits, representing potential targets of adaptive introgression. Genes related to mitochondrial functions and thermogenesis associated with adipose tissue were identified to be under selection. Overall, our data suggest introgression as a mechanism facilitating adaptation in wild sheep species and provide insights into the genetic mechanisms underlying cold adaptation in snow sheep.
KW - Ovis nivicola
KW - cold adaptation
KW - hybridization
KW - whole genome sequencing
UR - http://www.scopus.com/inward/record.url?scp=85120986532&partnerID=8YFLogxK
U2 - 10.1111/mec.16184
DO - 10.1111/mec.16184
M3 - Article
C2 - 34534381
AN - SCOPUS:85120986532
SN - 0962-1083
VL - 30
SP - 6701
EP - 6717
JO - Molecular Ecology
JF - Molecular Ecology
IS - 24
ER -