Milk fat is a key indicator for assessing the quality of dairy products. Recently, a growing number of studies have focused on the molecular mechanisms by which non-coding RNAs (ncRNAs) regulate milk fat synthesis. Long non-coding RNAs (lncRNAs) are non-coding transcripts longer than 200 nucleotides (nt), which exert diverse biological functions. LncRNAs are being increasingly recognized for their roles in milk fat synthesis. In this study, we found that LOC112442979 promotes lipid droplet accumulation and triacylglycerol (TAG) synthesis in bovine mammary epithelial cells (BMECs). Subsequently, we renamed the LOC112442979 as Mammary Lipid Synthesis-associated Transcript (MLST). Bioinformatics analysis predicted that MLST acts as a molecular sponge for miR-7 and that mTOR is a target gene of miR-7. Our findings demonstrate that MLST regulates the mTOR signaling pathway by sponging miR-7, thereby promoting milk fat synthesis, which provide valuable insights into the molecular mechanisms underlying milk quality improvement from the perspective of lncRNA-miRNA-mRNA regulatory network.

Read the full article in the Journal of Animal Science.