Goats and sheep are versatile domesticates that have been integrated into
diverse environments and production systems. Natural and artificial
selection have shaped the variation in the two species but, natural
selection has played the major role amongst indigenous flocks. To
investigate signals of natural selection, we analyzed genotype data
generated using the caprine and ovine 50K SNP BeadChips from Barki goats
and sheep that are indigenous to a hot arid environment in Egypt's
Coastal Zone of the Western Desert. We identify several candidate regions
under selection that spanned 119 genes. A majority of the genes are
involved in multiple signaling and, signal transduction pathways in a wide
variety of cellular and biochemical processes. In particular, selection
signatures spanning several genes which directly or indirectly influence
traits for adaptation to hot arid environments, such as thermo-tolerance
(melanogenesis) (FGF2, GNAI3, PLCB1), body size and development (BMP2,
BMP4, GJA3, GJB2), energy and digestive metabolism (several MYH, TRHDE,
ALDH1A3) and nervous and autoimmune response (GRIA1, IL2, IL7, IL21,
IL1R1) are identified. We also identified eight common candidate genes
under selection in the two species and a shared selection signature that
spanned a conserved syntenic segment to bovine chromosome 12 on caprine
and ovine chromosome 12 and 10 respectively, providing, most likely,
evidence for selection in a common environment in two different but
closely related species. Our study highlights the importance of indigenous
livestock as model organisms for investigating selection sweeps and
genome-wide association mapping. Plink file data for
Barki Ruminants (sheep and goats)The data contains SNP
genotype data for Barki sheep and goats that can be used in
Plink.plinkBarkiRuminants.zip