The Comparative Transcriptome Study Between Primary And Secondary Hair Follicles Development In Cashmere Goats

The hair is one of the important raw materials in textile industry, and it is also an important economic product of Inner Mongolia Cashmere goats. Because of the application of hair is limited by its fiber properties in the textile industry, the quality and production performance of the cashmere are the key factors affecting the economic value of Cashmere goat. Therefore, it is important to understand regulation mechanism and physiological characteristics during the hair follicle development, and explore the candidate gene that associated with hair growth. In this study, we performed the further analysis of the growth mechanism at the molecular level, the two main studies are as follows:1. In this study, in order to investigate the vary of differential expression genes to distinguish between the PFs and SFs. We selected RNA samples from 11 PFs and 7 SFs that included 145,525 exons. The KEGG pathway analysis of 4512 differentially expressed exons revealed that the most statistically significant metabolic pathway was related to the ubiquitin-mediated proteolysis pathway (UMPP) (P<3.32 E-07). In addition, the 51 exons of the UMPP that were differentially expressed between the different types of hair follicle (HFs) were compared by cluster analysis. This resulted in the PFs and SFs being divided into two classes. The expression level of two selected exons was analyzed by qRT-PCR, and the results indicated that the expression patterns were consistent with the deep sequencing results obtained by RNA-Seq. This study suggests that UMPP activation is a prominent signaling pathway for distinguishing the PFs and SFs of cashmere goats. It is also a meaningful contribution to the theoretical basis of the biological study of the HFs of cashmere goats by RNA-Seq technology.2. In order to investigate the vary of differential expression genes in the Nei Mongol cashmere goat hair follicles during anagen, the mRNA expression levels of different genes in skin hair follicles were detected from June to October using Illumina technology. Evaluation of transcriptomes was undertaken to understand the time-course gene expression involved in both follicle types. The samples were collected from June to October. Most of differentially expressed genes appeared between Jul-Aug in primary hair follicle(PF)and between Aug-Sep in secondary hair follicle(SF). Seven differentially expressed genes:FAM83C, LOC102185501, FYCO1, CTTNBP2NL, C6orf132, KRTAP29-1 and CRYBG3 were identified. Their expression demonstrated similar trends at different months of cashmere growth cycle and the SF postpone for about one month. These findings indicated the hysteresis in SF gene regulation comparing with PF could provide the useful theoretical basis to the molecular mechanism of cashmere regeneration.