Deciphering the genomic signatures of climate vulnerability across 77 sheep breeds
Abstract
Among domesticated species, sheep ( Ovis aries ) have achieved a wide geographic distribution due to their mobility, rusticity and ability to adapt to diverse environments and climatic conditions. Here, we characterise the genome-wide diversity of >1,000 sheep representing 77 autochthonous breeds spanning North Africa to Scandinavia using high-density genotype data. To provide a large-scale assessment of population vulnerability to climate change, we combine uni- and multivariate gene-environment association analyses, and quantify the deviation of the current genomic make-up of populations from that necessary for maintaining adaptation under climate change (genomic offset). We identify precipitation as a major driver of divergent selection and identify candidate adaptive loci overlapping genes with pleiotropic roles linking renal water balance and metabolic regulation, including glucose and insulin-related pathways. This coupling of osmoregulatory and metabolic functions likely underpins adaptation to variable drought regimes and extreme, fluctuating environments. Notably, genomic offset hot spots are identified in southwestern Europe, highlighting the need for targeted management to mitigate the effects of climate change on animal welfare and production in these regions. These findings shed light on the strategies for climate adaptation in sheep and provide insights for informed breeding programmes aimed at enhancing resilience in changing climate conditions.