Expression of keratin intermediate filament genes in wool follicles of Wiltshire sheep

摘要

Co-ordinated expression of keratin intermediate filament genes in the wool follicle is essential for the formation of the wool fibre. The expression patterns of three acidic (oKRTSl, oKRT35, oKRT38), one neutral-basic (oKRT85) and one acidic inner root sheath keratin (oKRT27) were localised by in situ hybridisation in the wool follicles of Wiltshire sheep. All five genes show distinct expression patterns in the primary wool follicles of the face and lower leg, but have comparable keratinisation zonesto their human orthologues. During follicle regression, the expression of these genes is first attenuated distally, gradually becoming restricted to proximal regions before terminating in dormant follicles. The involvement of the expression of oKRT27, oKRTSl and oKRT85, but not oKRT35 and oKRT38, in brush-end formation indicates specialised regulation of keratin expression in the development of this anchoring structure. Intriguingly, significant differences in the expression of cortical oKRT31, oKRT35,oKRT38 and oKRT85 between primary and secondary follicles were identified. The association of asymmetrical expression of some keratins with follicle curvature raises the possibility of a role in fibre crimp formation. Future studies of these and other keratins will generate an understanding of the structural basis of fibre attributes that could contribute to development of novel wool fibres for specific applications.