Identification Of Cycle-associated MiRNAs In Inner Mongolia Cashmere Goat Skin And Hair Follicles

MicroRNA (miRNAs) is a newly identified class of20-24nt non-protein-coding and endogenous small RNA. Recent researches demonstrated that a large number of miRNAs are involved in the development of epidermis and hair follicles, and the cyclical development of hair follicles. In this study, areas of skin where the cashmere grows in anagen, catagen and telogen were sampled. Combined with bioinformatic method, the types, abundance, family and targets of miRNAs in goat were analyzed by small RNA deep sequencing technology, which was based on Illumina/Solexa principium. The resultes enriched the repertoire of goat miRNAs and provided more profound insights into miRNA expression changes in the hair follicle cycle development. The main results were as follows:(1) We obtained10,644,467reads,11,951,819reads and11,032,157reads, In anagen, catagen and telogen, respectively. By small RNA annotation, we identified3,381distinct reads and after applying the classification statistics we obtained316miRNAs. Among them,68miRNAs are conserved in goat and have been reported in NCBI; the remaining248miRNA were conserved in other species but have not been reported in goat.(2) We found that the miRNAs that were co-expressed in goat and sheep were located in the same region of the respective chromosomes and may play an essential role in skin and hair follicle development.(3) In shamples of different development phases, we obtained15anagen-specific miRNAs,7catagen-specific miRNAs and8telogen-specific miRNAs in a total of344conserved miRNAs.(4) Furthermore, we identified22novel miRNAs By target prediction for novel miRNA candidates,86519target gene were predicted. Through KEGG pathway analysis, MAPK pathway is considered to be critical in skin and hair follicles. Both the known and novel miRNAs were confirmed by a second sequencing using the same method as was used in the first.