GENE-TRANSFER INTO XENOPUS HEPATOCYTES - TRANSCRIPTIONAL REGULATION BY MEMBERS OF THE NUCLEAR RECEPTOR SUPERFAMILY

A procedure to culture Xenopus laevis hepatocytes that allows the cell s in primary culture to be subjected to gene transfer experiments has been developed. The cultured cells continue to present tissue-specific markers such as expression of the albumin gene or estrogen-controlled vitellogenin gene expression, which are both restricted to liver. Two efficient and reproducible gene transfer procedures have been adapted to the Xenopus hepatocytes, namely lipofection and calcium phosphate- mediated precipitation. The transcription of transfected reporter gene s controlled by estrogen-, glucocorticoid- or peroxisome proliferator- response elements was stimulated by endogenous or co-transfected recep tor in a ligand-dependent manner. Furthermore, the expression of a rep orter gene under the control of the entire promoter of the vitellogeni n B1 gene mimicked the expression of the chromosomal vitellogenin gene with respect to basal and estrogen-induced activity. Thus, this cultu re-transfection system will prove very useful to study the regulation of genes expressed in the liver under the control of various hormones or xenobiotics.