Turpan Black (TBL) and Altay (ALT) sheep are indigenous breeds adapted to extreme heat and severe cold in their respective native environments. However, the mechanisms underlying their divergent meat quality remain unclear. Using longissimus dorsi muscle from 15 TBL and 15 ALT sheep, we integrated phenotypic evaluation with non-targeted metabolomics and proteomics to elucidate the impact of environmental adaptation on ovine meat quality. Compared to the cold-adapted ALT sheep, the heat-tolerant TBL sheep exhibited lower post-mortem pH, reduced cooking loss, smaller muscle fiber cross-sectional area, and elevated selenium and magnesium levels. Multi-omics identified 99 differentially expressed proteins and 364 differentially expressed metabolites. Core divergence was enriched in lipid and amino acid metabolism and stress response networks, particularly the Apelin signaling, glycerophospholipid metabolism, and ferroptosis pathways. Lipid remodeling driven by glycerophospholipid metabolism emerged as a critical bridge linking adaptation to meat quality. Notably, glycero-3-phosphocholine, regulated by GPCPD1 and related enzymes, maintained cell membrane homeostasis and osmotic pressure, thereby enhancing water-holding capacity and tenderness. These findings reveal the multi-omics basis of climate-driven divergence in ovine meat quality, offering theoretical support for breeding stress-resilient, high-quality indigenous sheep breeds in extreme environments.

This study investigates the mechanisms underlying drought adaptability in Duolang sheep, a local breed from two distinct habitats in Xinjiang—an arid southern region and a grassland northern region—aiming to identify key factors driving differential environmental adaptation. Integrated multi-omics analyses were performed, including serum biochemical assays, untargeted metabolomics of perirenal and tail fat tissues, and transcriptomic profiling of lung, liver, and kidney samples. Our results revealed notable differences: (1) serum levels of GSH-Px, IL-2, and IgG were significantly higher in the southern group (p < 0.01); (2) metabolomic analysis identified key differential metabolites, including EPA (involved in unsaturated fatty acid biosynthesis), choline (glycerophospholipid metabolism), L-serine and glutathione (cofactor biosynthesis), and taurine (sulfur metabolism); and (3) transcriptomic analysis revealed significant differential expression of genes such as FGF21 (thermogenesis), CD14 and DUSP2 (MAPK signaling pathway), GOT1 (arginine biosynthesis), and AVPR2 (vasopressin-regulated water reabsorption). Integrative correlation analysis further indicated that glutathione, EPA, GOT1, and CD14 are involved in energy and lipid metabolism, while taurine, AVPR2, and DUSP2 contribute to oxidative stress resistance and immune regulation. These molecular and metabolic adjustments collectively enhance drought adaptability in southern Xinjiang Duolang sheep. In conclusion, adaptation to arid environments requires enhanced antioxidant capacity and immune function, with metabolites such as EPA supporting lipid metabolism and genes such as FGF21 regulating fatty acid oxidation to limit triglyceride accumulation.

Excessive tail fat deposition in sheep limits feed conversion efficiency and carcass quality, making the genetic improvement of this trait a priority. This study aimed to elucidate the molecular mechanisms regulating ovine fat metabolism. We analyzed the tissue specific expression of two candidate microRNAs, miR-320d and miR-151b, alongside their target genes SCD and ACACA, across tissues from fat-tailed and thin-tailed sheep using quantitative real-time PCR. The regulatory function of the tail fat specific miR-320d was further validated in vitro using isolated ovine tail preadipocytes. Results indicated that miR-320d and miR-151b are specifically highly expressed in tail and subcutaneous adipose tissues, respectively, and correlate negatively with their target genes. Dual-luciferase reporter assays confirmed that miR-320d directly targets the 3′UTR of SCD and suppresses its transcription. Overexpression of miR-320d significantly inhibited the proliferation of tail preadipocytes and downregulated downstream genes in the fatty acid metabolism pathway, including ACACA, ELOVL6, ELOVL5, and FASN. In conclusion, miR-320d exerts a negative regulatory effect on sheep tail fat deposition by suppressing preadipocyte proliferation and fatty acid synthesis, while miR-151b emerges as a potential candidate for subcutaneous fat regulation.

This study elucidates the biochemical mechanisms by which extreme high-altitude environments are associated with the remodeling of the skeletal muscle flavor profile in sheep. Using Bayinbuluke (high-altitude) and Turpan Black (low-altitude) sheep, we integrated volatilomics, metabolomics, transcriptomics, and proteomics to map flavor precursor networks. Odor activity value analysis revealed that high-altitude meat exhibited sub-threshold suppression of animal off-flavors, such as p-cresol, while significantly amplifying premium fruity esters. Targeted metabolomics attributed this sensory inversion to a structural shift in the precursor pool, specifically the enrichment of highly reactive polyunsaturated fatty acids, L-cysteine, and rhamnose. Multi-omics integration demonstrated that cold and hypoxic stresses are associated with metabolic reprogramming. The synergistic downregulation of the GPAT3 gene and APOC3 protein was associated with redirected lipid flux, suggesting a mechanism for functional fatty acid accumulation. Simultaneously, the pronounced upregulation of the CTH gene, potentially driven by antioxidant defense needs, coincided with substantial L-cysteine accumulation. Correlation networks suggested that this precursor shift is negatively correlated with off-flavor generation, possibly via competitive thermal degradation. In conclusion, extreme ecological stress is associated with convergent metabolic reprogramming, contributing to the reconstruction of the flavor precursor pool to alter the characteristic lipid aroma of plateau meat. While these findings provide a comprehensive structural blueprint of plateau meat characteristics, the proposed mechanisms remain hypothetical and warrant future functional and sensory validation.