MicroRNA profile analysis on duck feather follicle and skin with high-throughput sequencing technology.

Skin acts an important protection role in animal survival and it evolves with the animal divergence. We identified the conserved miRNA families of skin among duck and other species. Cluster analysis showed that the species with similar skin characteristics were clustered into the same group, indicating miRNAs are important in skin function and skin evolution. The miRNA profiles demonstrated that different miRNA regulation mechanism may exist in contour feather follicles (with the surrounding skin) and down feather follicles (with the surrounding skin). Comparing the highly abundant miRNAs with those of mammalian hair follicles and skins, different miRNAs and miRNA families were found, suggesting the different ways in feather follicles and mammalian hair follicles. Bioinformatics prediction indicated that seven miRNAs probably targeted the genes of Wnt/β-catenin, Shh/BMP and Notch pathways which were important in feather morphogenesis. Further analysis should be conducted to experimentally validate the relationships between miRNAs and their predicted target genes because the target genes were based exclusively upon the bioinformatics.