Identification of key miRNAs regulating fat metabolism based on RNA-seq from fat-tailed sheep and F2 of wild Argali

•Domesticized sheep (Bashby sheep, fat-tailed) and the F2 with their wild ancestors (Bashby sheep × Wild Argali, thin-tailed) have become important subjects for this study.•miR-320d, miR-151b and miR-6715 were discovered for the first time in the regulation of sheep tail fat deposition.•miR-320d may directly and negatively regulate tail fat deposition by targeting SCD, while miR-151b may indirectly and negatively regulate tail fat deposition by targeting ACACA.