R.C. Noble1, D.C. Deeming2, M.W.J. Ferguson2, R. McCartney1
1Department of Poultry Science, The West of Scotland College, Auchincruive, Ayr KA6 5HW, Scotland (Tel: 0292 520331)
2Department of Cell and Structural Biology, The University of Manchester, Coupland III Building, Coupland Street, Manchester M13 9PL, England (Tel: 061 275 6775)