Candidate genes and genomic regions relevant for adaptation to extreme climates in livestock

Over millennia, livestock species have developed remarkable genetic adaptations to thrive in extreme environments such as freezing cold, intense heat, and high-altitude regions. Advances in sequencing technologies and genome-wide tools have uncovered the genetic basis of these adaptations across livestock species. This review synthesizes genomic information reported for cattle, sheep, goats, and yak to identify key genes and genomic regions relevant to extreme climates. We aggregated thousands of reported genomic hits related to extreme climates and identified approximately 400 genes that were consistently replicated across studies. These include well-known genes associated with environmental stress (e.g., HSF1, HSPB9, DNAJC18, and KITG) as well as less-described candidates (e.g., EGR1, SIL1, SCRIB, and REEP2). Meta-gene enrichment revealed that heat/drought tolerance genes are primarily involved in immune function, transport, and genomic stability, while cold/hypoxia-related genes are strongly associated with cellular structural integrity, such as cell-cell adhesion. Transcriptional and epigenetic regulation emerged as central biological themes associated with both cold/hypoxia and heat/drought adaptation, suggesting that these mechanisms are evolutionarily conserved pathways driving climate resilience. Key hub genes identified in this review (e.g., HSPA4, DNAJC7, STAT3, CD48, CD84, CDC23, and CPSF1) are promising targets for future functional research. Overall, this review provides a valuable genetic resource for understanding livestock adaptation and offers novel insights into biological mechanisms underpinning resilience to extreme climates. These findings may contribute to developing targeted breeding and gene-editing strategies, providing potential solutions for sustainable livestock production in the face of climate change.