The transcription factor Pax2 is essential for kidney development in mice, and overexpression of Pax2 in chick embryos leads to ectopic formation of nephric structures. We have generated embryonic stem (ES) cell lines that repress Pax2 expression in a tetracycline-dependent manner. In the absence of tetracycline, embryoid bodies derived from these cell lines expressed Pax2 and subsequently integrin alpha8 and aquaporin-1 (Aqp1), both of which are possibly involved in kidney development. Considering the slow induction kinetics, our data suggest that Pax2 and additional factors that are induced in embryoid bodies synergistically regulate the two targets. The ES cell lines with inducible Pax2 expression will also be useful for dissecting genetic cascades functioning in a variety of organ development.