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

Abstract

Background: Mammals have physiological reprogramming adaptation ability to changing seasonal light and temperature, through their biological clocks maintained by circadian rhythm, photoperiodism and thermoperiodism. These seasonal differences do not only affect vital activities of animals like migration, reproduction, sleeping, but also cause dramatic changes in their economically important characters (e.g. fur quality, fattening levels and milk yield). 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. Methods and Results: 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 and anagen, sampled in February and June, respectively. HOXC13 showed high level of expression in anagen phase whereas expression was undetectable in telogen phase. TGFBR2, FGF-5, and BMP-2 were significantly upregulated in anagen, while KAP9.2 expression showed no difference between two phases. Conclusions: This is the first study on hair follicle-related genes in the angora goat and revealed that these genes differ between geographic zones and/or breeds. Additionally, we speculate that overexpression of HOXC13 might be one of the underlying factors associated with non-medullary hair nature, making the mohair more shiny and silky in Angora goats.