the Effects of Fibroblast Growth Factors 1 and 2 on Fibre Growth of Wool Follicles in Culture.

Abstract

The effects of fibroblast growth factor-1 (FGF-1) and FGF-2 on fibre growth and follicle function were examined using a previously described procedure to culture wool follicles. Because the FGFs bind to glycosaminoglycan components of the extra-cellular matrix;we also investigated interactions between FGF-1 and FGF-2 with heparin on wool fibre growth. Individual follicles were microdissected from Merino sheepskin and transferred to culture. Follicles increased in length for 6 days;and in all groups;no significant differences in follicle length were observed. Increase in follicle length was associated with fibre growth;follicles maintained normal anagen morphology and incorporated [3H]thymidine into the bulb and outer root sheath cells. Follicles in all treatments continued to produce fibre keratins;as detected by immunohistochemistry. However;the patterns of fibre and cytoskeletal proteins incorporating [35S]methionine in control and treated follicles were significantly different. We found a considerable decrease in the intermediate filament keratins or low sulphur proteins in follicles cultured in the presence of FGF-1 and FGF-2 compared to controls. The majority of proteins detected in these samples were acidic high sulphur proteins. These studies provide evidence for a specific role for the fibroblast growth factors in the regulation of fibre differentiation.