Résumé : By means of somatic cell hybrids segregating either human or rat chromosomes, we determined the chromosome localization of three genes encoding transcription factors expressed in hepatocytes, namely, C/EBP (CCAAT/enhancer binding protein), DBP (D site of albumin promoter binding protein), and HNF1/LFB-1 (designated transcription factor 1, gene symbol: TCF1), and of the hepatocyte growth factor gene, which is identical to the mitogenic and chemotactic factor designated scatter factor (gene symbol:HGF). The CEBP and DBP genes, encoding two related transcription factors, were found to be syntenic both on human chromosome 19 and on rat chromosome 1. These results provide further evidence for conservation of synteny on these two chromosomes (and on mouse chromosome 7). The TCF1 gene was found to be located on chromosome 12 in both man and rat, thereby defining a new segment of homology between these two species (and a segment of mouse chromosome 5). The HGF gene was mapped to rat chromosome 4, confirming homology between this chromosome and human chromosome 7, which carries the human HGF gene.