Study On Expression Of Clock Genes In Hair Follicle Of Cashmere Goat

The growth of cashmere hair showed a seasonal variation. As a peripheral tissue localized at the interface between internal and external environments, skin performs functions which are critical for the preservation of body homeostasis, in coordination with environmental changes. Some of these functions undergo daily variations, such as temperature or water loss, suggesting the presence of time-keeping mechanisms. Rhythmic functions are controlled by a network of circadian oscillators present virtually in every cell and coordinated by the central clock located in the Suprachiasmatic nucleus. Therefore, the interaction of Clock gene affected the growth of hair follicle. In this study, to further confirm whether the Clock gene controled the growth of hair follicle on a 24h cycle. Circadian rhythms are generated by conserved transcriptional-translational feedback loops involving 13 Clock genes, among which CSNK1E、CSNK1D、TIM、CLOCK、PER1、 PER2、PER3、TIM、CRY1、CRY2、BHLHE40、BHLHE41 and ARNTL. We used RNA-Seq analysised expression patterns of Clock genes in different growth periods primary follicles and secondary follicles. In addition, in order to further study expression of Clock gene in secondary follicle of skin, think of CLOCK, TIM, PER1 and CRYl as the abject of study, using quantitative PCR to analysis 4 clock genes.Through the above experimental data obtained the following conclusions:1.CSNK1E gene was highly expressed in hair follicles, which expression levels several times higher than other Clock genes. Expression levels of Clock genes in primary follicles of skin were:CSNK1E> CSNK1D、BHLHE40、ARNTL> CRY1、PER1、 CLOCK、CRY2、NR1D1> PER2>PER3、BHLHE41; Expression levels of Clock genes in secondary follicles of skin were:CSNK1E> CSNKID、ARNTL、BHLHE40> NR1D1 、PER1、CRY1、CRY2、BHLHE41、CLOCK、PER2>PER3.2.There are significant differences expression levels of CSNK1D, CLOCK, CRY2, PER3 and BHLHE41 genes in skin between the changes of growth of hair follicle period and the sampling time. Expression of NR1D1 gene in primary hair follicles with the same growth period in different sampling time had significantly differential. ARNTL and PER2 gene with the development of secondary follicles in different periods, which expression quantity had significant differences.3.Expression levels of (RT-PCR) Clock genes in secondary follicles of skin were: CLOCK> TIM> PER1> CRY1.4.Flourishing period in skin, rhythmic expression of high-amplitude CLOCK, PER1, TIM, CRY1 appeared at 04:00,08:00,08:00,16:00; Telogening periods in skin, rhythmic expression of high-amplitude CLOCK, PER1, TIM, CRY1 appeared at 08:00、04:00、 04:00、16:00.