Melatonin regulating the expression of miRNAs involved in hair follicle cycle of cashmere goats skin.

Melatonin and microRNAs (miRNAs) play important roles in regulating hair follicle development. However, the effect of melatonin on the expression pattern of miRNAs in skin and follicle of cashmere goats remain largely undefined. To explore the mechanism of melatonin affecting cashmere growth mediated by miRNAs, the effect of melatonin implants administered in Nei Mongol cashmere goats was assessed. In the experiment, five yearling does were implanted with melatonin, with the remaining other five females as control group. The expression of six candidate miRNAs was quantified by reverse transcription-real time polymerase chain reaction (RT-qPCR). The results indicated that melatonin significantly altered the expression pattern of miRNAs. Except for let-7a, the expression levels of miR-203, miR-205, miR-96, miR-183 and miR-199a occur three transitions during a cashmere cycle; melatonin changed the co-expression pattern of miRNAs. The correlation coefficient between miRNAs is 0.87-0.99 in control group(P<0.01). Compared with the control group, the correlation coefficient between some miRNAs (let-7a and miR-96, miR-199a, miR-205;miR-203 and miR-96, miR-199a; miR-96 and miR-183; miR-183 and miR-199a) was significantly weakened in melatonin group. Melatonin might induce second growth of cashmere mediated by down-regulating the expression level of some miRNAs in June in melatonin implanted group.