Affiliation: | (1) Department of Gene Regulation and Differentiation, GBF-Gesellschaft für Biotechnologische Forschung mbH., Mascheroder Weg 1, 38124 Braunschweig, FRG;(2) Instituto de Biologia Experimental e Tecnologica, Laboratory of Biochemical Engineering, IBET, Apartado 12, Oeiras, Portugal |