Molecular cloning, characterization and expression of miR-15a-3p and miR-15b-3p in dairy cattle

•miR-15a-3p and miR-15b-3p was identified in bovine.•Fourteen potential target genes were predicted.•miR-15a-3p was significantly up-regulated in mammary-infected tissues.•miR-15b-3p was significantly down-regulated in mammary-infected tissues.•miR-15a-3p and miR-15b-3p play important roles in the mastitis resistance.

MicroRNA (miRNA) plays an important role in modulating immune responses. We identified miR-15a-3p and miR-15b-3p which were immune related in bovine. Fourteen potential target genes were predicted. Both miR-15a-3p and miR-15b-3p showed significant differential expression patterns in healthy and mastitis infected cattle (P < 0.01). Expression patterns of the two miRNAs provide important information on the relationships between mastitis and miRNA expression.