The genomic analysis of Southwest Asian indigenous goats revealed
evidence of ancient adaptive introgression related to desert climate
Abstract
Understanding how evolutionary pressures relating to climate changes
have shaped the genetic background of present day domestic animals is a
fundamental pursuit in biology. Here, we generated whole genome sequence
data from native goat populations in Iraq and Pakistan countries.
Together with published data from worldwide modern, historical remains
and wild caprid species (including ibex like species, bezoar and markhor
goats) we explore genetic population structure, ancestry components and
signatures of natural positive selection of native goat populations in
Southwest Asia (SWA) region. Our results revealed that the genetic
structure of SWA goats was deeply influenced by the gene flow from
eastern Mediterranean area during the Chalcolithic period, which may
reflect the adaptation to the gradual warming and aridity in this
region. Furthermore, a comparative genomic analysis revealed adaptive
introgression of KITLG locus from the Nubian ibex (Capra nubiana) into
African and SWA goats. The frequency of the selected allele at this
locus was found significantly higher among the goat populations located
close to the north-east of Africa. The Nubian ibex is a wild relative of
the domestic goat that is well adapted to the arid mountains of north
Africa and the Middle East. These results provide new insights into the
genetic composition and history of goat populations in SWA region.