Abstract

Simple SummaryMarbling, the fat found inside muscle, is a key factor in determining beef quality, making the meat tender and flavorful. Yunling cattle, a breed from China, are known for their potential to produce excellent marbling, but the biological reasons behind this trait are not fully understood. This study investigated the muscle characteristics of Yunling cattle by comparing them with Angus and Simmental breeds. By analyzing gene activity, fat composition, and amino acid levels, we identified unique molecular patterns in Yunling cattle. We found that specific groups of genes work together with distinct fat molecules and amino acids to promote marbling formation. Specifically, Yunling cattle exhibit a unique energy metabolism and cell communication system that supports fat deposition. These results provide a scientific explanation for the superior meat quality of Yunling cattle. This knowledge is valuable for the beef industry as it helps breeders select the best animals, leading to genetic improvements and ensuring a consistent supply of high-quality, tasty beef for consumers.Marbling, or intramuscular fat (IMF), is a primary determinant of high-quality beef, defining key sensory attributes and nutritional value. Yunling (YL) cattle, an indigenous breed from Yunnan, China, are renowned for their superior marbling, yet the underlying molecular mechanisms remain unclear. This study employed an integrated transcriptomic, lipidomic, and amino acid metabolomic approach to systematically compare the multi-omics profiles of the longissimus dorsi muscle among YL, Angus (AGS), and Simmental (XMTE) cattle. Transcriptome analysis identified 2053 and 2156 differentially expressed genes (DEGs) in XMTE vs. YL and AGS vs. YL, respectively. These DEGs were primarily enriched in the PI3K-Akt and MAPK signaling pathways, as well as oxidative phosphorylation. Lipidomic analysis revealed a distinct lipid profile in YL cattle, identifying 27 characteristic lipid molecules (e.g.