Embryonic stem (ES) cells and induced pluripotent stem (iPS) cells in rats.

Over the past 25 years, the reverse genetic approach including precise and conditional replacement or loss of gene function at a specific locus was considered possible only in mice due to the absence of embryonic stem (ES) or induced pluripotent stem (iPS) cell lines in other species. Recently, however, stem cell technology in rats has become available for biomedical research. In this paper we overview the recent progress of rat ES and iPS cell technology. Starting from the establishment of rat ES cells, the use of ES cells for foreign gene transfer and endogenous gene knock-out is discussed, followed by the successful establishment of rat iPS cells and the generation of an iPS cell-derived organ via interspecific blastocyst complementation. Finally, the possible contribution of rat stem cell technology to reproductive medicine is described.