Whole-genome sequencing reveals genetic architecture and selection signatures of Kazakh cattle

Local cattle breeds play a critical role in breeding programs due to their genetic adaptations to diverse environmental conditions. However, the genomic architecture of local cattle breeds in Kazakhstan remains largely unexplored. This study utilized whole-genome sequencing data from Kazakh cattle to elucidate their genetic composition, uncovering three primary ancestral components: European, Eurasian, and East Asian taurine. The East Asian taurine lineage likely represents the earliest genetic contribution to Kazakh cattle but was largely replaced by subsequent waves of cattle migrations across Eurasia, leaving only a minor genetic signature in the current cattle population. In contrast, Eurasian taurine ancestry predominated in the Alatau and Kazakh local breeds, while the European taurine component was most prevalent in Kazakh white-headed cattle, consistent with their documented breeding history. Kazakh cattle exhibited higher genetic diversity and lower inbreeding coefficients compared to European commercial breeds, reflecting reduced exposure to intense artificial selection. A strong selection signal was identified on chromosome 6 at a locus encompassing PDGFRA, KIT, and KDR, which may be associated with the white-headed pigmentation characteristic of Kazakh white-headed cattle. Additional genes under selection were linked to lipid metabolism (IRS1, PRKG1, and ADCY8), meat production traits (KCNMA1, PDGFRA, HIF1A, and ANTXR1), and dairy production (ATP2B1, DHX15, FUK, NEGR1, CCDC91, COG4, and PTK2B). This study represents the first comprehensive analysis of nuclear genome data from local Kazakh cattle. It highlights the impact of historical cattle migrations across Eurasia on their genetic landscape and identifies key genomic regions under selection. These findings advance our understanding of the evolutionary history of cattle and offer valuable genetic resources for future breeding strategies.