Assessing the influence of cow breeds on milk miRNome

International audience

Английский. OBJECTIVES: MicroRNAs (small noncoding RNAs, 18-25 nucleotides) regulate the expression of up to 60% of genes and influence many biological processes. Resistant and stable, they are present in milk, where their abundance is regulated, in part, by genetic factors. This study aimed to evaluate miRNome (microRNA composition) variations according to two dairy cow breeds with contrasting lactation performances, and to assess their role in the biosynthesis of milk constituents and its impact on nutrition.METHODS: Milk miRNomes from 10 Montbéliarde and 8 Holstein cows were characterized by Illumina high-throughput sequencing. Annotation and quantification were performed using miRDeep2. Differential analysis of the milk miRNomes with the Limma package identified differentially abundant microRNAs. Target genes and biological processes impacted by the identified microRNAs were studied using TargetScan and DAVID. RESULTS: We characterized 1924 and 1625 microRNAs in the milk of Montbéliarde and Holstein, respectively, with 1490 in common. The comparison of miRNomes reveals 115 differentially abundant microRNAs (Padj<0.05). Biological process analysis highlighted microRNAs involved in lipid and protein metabolism and cellular process. Their targets are mainly involved in transcriptional activation of genes and ATP binding, which are functions required for lactation.CONCLUSIONS: We highlighted a milk microRNA composition specific to each bovine breed, showing a significant impact of the genetic background on milk miRNomes. The identified differences could potentially be responsible for variabilities in milk production and composition. The influence of bovine milk miRNome variations on the nutritional quality of milk and human health needs further investigation.