Molecular Characterization Of MicroRNAs In Regulating The Growth Of Secondary Hair Follicles In Cashmere Goats

Cashmere is grown from secondary hair follicles.Secondary hair follicles grow periodically in the season,including anagen,catagen,and telogen.This paper aims to study the regulation mechanism of mi RNA on the cycle growth and development of secondary hair follicles.First,micro RNAs expressed in three growth stages of cashmere secondary hair follicles were obtained through high-throughput transcriptome studies.Secondly,quantitative and localized analysis of highly expressed mi RNAs was performed.Finally,we focused on the regulation of mi R-143 on the growth and development of secondary hair follicles.The main results of this study are as follows:(1)Through high-throughput sequencing and bioinformatics analysis,579 expressed mi RNAs were obtained,of which 418 were known mi RNAs in goats and 161 were new mi RNA candidate genes.(2)q RT-PCR results showed that mi RNA expression was tissue specific.mi R-92 b and mi R-203 are highly expressed in epidermal tissues.The results of in situ hybridization showed that mi R-203 was localized in the matrix cells and the hair shaft,and the expression level in the hair shaft was higher than that in the matrix cells.(3)Sequencing results showed that mi RNA-143 has high expression in secondary hair follicles,and has time periodicity and tissue specificity.Mi R-143 has a low expression level in the early anagen,and has a higher expression level in the late anagen,telogen and catagen.The results of in situ hybridization showed that mi R-143 was expressed in hair shaft and matrix cells,and the expression level in matrix cells was higher than that in hair shaft cells,indicating that mi R-143 may play an important role in regulating the atrophy of hairy dermal papilla cells in the secondary hair follicle from the catagen to the telogen.(4)Bioinformatics analysis predicted all possible target genes of mi R-143 and determined that ITGA6 is a potential target gene of mi R-143 in the regulation of secondary hair follicles.The results of immunohistochemistry showed that the high expression of ITGA6 was in the bulge,while the relative expression of mi RNA-143 was low,and there was a potential negative regulation relationship between them.(5)Luciferase reporter results revealed that mi R-143 and ITGA6 have a targeted relationship.This indicates that mi R-143 acts on the target site of the 3'UTR of ITGA6,inhibits the translation of the gene ITGA6,and regulates the cycle growth and development of secondary hair follicles.