Abstract: In order to explore the species and functions of microRNAs (miRNAs) in donkey milk exosomes, Illumina sequencing technique was used to sequence the small non-coding RNAs (sRNAs) in donkey milk exosomes, and identify the miRNAs in them through bioinformatic analysis using human milk miRNAs as the control. After quality control, the length of the sRNAs in donkey milk exosomes was mainly distributed between 18 and 22 nt, and a total of 212 miRNAs were identified, including 16 known ones and 196 new ones. Gene Ontology (GO) enrichment analysis showed that the functions of the miRNAs in donkey milk exosomes were similar to those of human milk miRNAs, such as constituting cells, organelles and other components, binding and catalytic activity and participating in the processes of cell metabolism and biological regulation. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the miRNAs in donkey milk exosomes participated in the synthesis and secretion of aldosterone, the Hedgehog signaling pathway, mitochondrial regulation and cancer pathways.

Key words: donkey milk exosomes; human milk exosomes; miRNA; Illumina sequencing