Multi-omics combined analysis of metabolic and transcriptional profiles of abdominal adipose color differentiation in Kazakh horses

Fat color is one of the most economically important traits in meat marketing.To identify the molecular characteristics underlying abdominal fat color differentiation in Kazakh horses, this study employed a multi-omics approach, including targeted metabolomics (fatty acids and amino acids), transcriptomics, and untargeted metabolomics, to analyze fat tissues of different colors.Fatty acid composition analysis revealed no significant differences in total saturated fatty acids (SFAs) or total unsaturated fatty acids (UFAs) between white adipose tissue (WAT) and yellow adipose tissue (YAT) (p > 0.05). However, YAT exhibited significantly higher levels of C15:0 and C17:1 (p < 0.05) and extremely significantly higher levels of C21:0 (p < 0.01) compared to WAT, while C22:1n9 was significantly lower in YAT (p < 0.05).Amino acid composition analysis showed that aspartic acid levels in WAT were extremely significantly higher than in YAT (p < 0.01), approximately 3.3 times greater.Furthermore, integrated transcriptomic and metabolomic analyses identified LPGAT1,AKT2, ADH5,as well as stearic acid and inositol, as key genes and biomarkers influencing fat color differentiation.