[1] Lab Genet Cellulaire, F-31326 Castanet Tolosan, France
[2] MRC, Mammalian Genet Unit, Harwell OX11 ORD, Oxon, England
[3] UK Mouse Genome Ctr, Harwell OX11 ORD, Oxon, England
[4] La Trobe Univ, Dept Genet & Evolut, Bundoora, Vic 3083, Australia
[5] Iowa State Univ, Dept Anim Sci, Ames, IA 50011 USA
[6] Univ Minnesota, Coll Vet Med, Program Comparat Genom, Food Anim Biotechnol Ctr, St Paul, MN 55108 USA
[7] Texas A&M Univ, Dept Vet Pathol, College Stn, TX 77483 USA