ABSTRACT
In 1989 we began a transgenic sheep programme by attempting to target heterologous gene expression to the wool follicle, using a mouse keratin (KER) promoter. Success in these experiments led us to link the KER promoter to a sheep insulin-like growth factor 1 cDNA, with the aim of affecting follicular metabolism and thus wool production or properties. To establish the technology and to demonstrate expression in the wool follicle, transgenic sheep were produced with the mouse KER promoter linked to the bacterial chloramphenicol acetyl transferase gene. A progeny test in 1994 revealed increased fleece weight in transgenic animals, with little effect on fibre characteristics. The mouse promoter is shown to function normally in transgenic sheep, directing gene expression to the wool follicle with a pattern that correlates with the physiological activity of the follicle in terms of wool growth. Wool production and properties were compared between transgenics and their non-transgenic half-sibs during the lamb year.
