Abstract

Seasonal variation in wool growth has major impacts on production and fibre characteristics. These changes in wool follicle output are driven, at least in part, by circulating prolactin. We therefore localised prolactin receptors (PRLR) in skin from Wiltshire sheep over a wool follicle cycle induced by prolactin. PRLR expression was visualised by in situ hybridisation, immunocytochemistry and radioligand binding. The three approaches showed concordant distributions of PRLR and its mRNA. PRLR mRNA was most abundant in the dermal papilla, but also evident in the outer root sheath, hair germ, skin glands and epidermis. Expression in the hair germ was up-regulated in telogen. Location of PRLR in the dermal papilla and outer root sheath indicates action of prolactin directly on the growth controlling cells within wool follicles. These spatial and cycle-related patterns of PRLR expression contribute to the growing knowledge of the control of wool growth and its application in the wool industry.

AJ, Nixon, VJ Choy, CA Ford, and AJ Pearson

Proceedings of the New Zealand Society of Animal Production, Volume 58, , 298-302, 1998