Affiliation: | 1 Institut de Biologie Animale, Université de Lausanne, Bâtiment de Biologie, 1015, Lausanne, Switzerland 2 Laboratory of Molecular Growth Regulation, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, U.S.A. 3 Max-Planck-Institut für Entwicklungsbiologie, 7400, Tübingen, Germany |