Seasonal Gene Expression Profile Responsible for Hair Follicle Development in Angora Goats

Mammals have physiological reprogramming adaptation ability to changing seasonal light and temperature, through their biological clocks maintained by circadian rhythm, photoperiodism and thermoperiodism. Seasonal differences do not only affect vital activities of animals like migration, reproduction, and sleeping, but also cause dramatic changes in their economically important characteristics (e.g. fur quality and fattening level). Mohair is constituted of non-medullary hairs produced by secondary hair follicles in Angora goats and the effects of seasonal differences on mohair structure and related genes are still unknown. We examined the gene expression levels of BMP-2, FGF-5, HOXC13, KAP9.2 and TGFBR2 normalized with GAPDH in skin biopsies taken from Angora goats (n=20) in two different follicle development stages; telogen (in February) and anagen (in June). HOXC13 showed overexpression in anagen phase (P<0.005) whereas expression was undetectable in telogen phase. BMP-2 (P<0.005), FGF-5 (P<0.005) and TGFBR2 (P<0.01) were significantly upregulated in anagen, while KAP9.2 expression showed no difference between two phases. This is the first study on hair follicle-related genes in the angora goat. Additionally, depending the role of HOXC13 in pathways, it suggests that its overexpression may be one of the main factors associated with the non-medullary hair structure in Angora goats.