Résumé : A panel of hybrid clones segregating rat chromosomes in a mouse background was used to determine the chromosomal localization of three genes specifically expressed in hepato-cytes. The phenylalanine hydroxylase, tyrosine aminotransferase. and pyruvate kinase genes were assigned to rat ehromosomes 7. 19. and 2. respectively. © 1990 S. Karger AG, Basel.