[In vitro induction of differentiation from embryonic stem cells: looking forward to regenerative medicine]

Embryonic stem (ES) cells are pluripotential cells, and enable us to study mechanisms of cell differentiation. Gene disruption of ES cells by homologous recombination is to be clear the function of targeted genes. Recently, it has been reported that bone marrow hematopoietic stem cells have a potential to differentiate into neuronal cell, muscle cell, liver cell, epidermal cell, and also epithelial cell lineages. Moreover, cloned animals from somatic cell nuclei were produced. Here, we show osteoclastogenesis, and endothelial cell-genesis from single ES cell, and discuss the possibility for organogenesis in vitro. Furthermore, we would like to summon to understand usefulness and dangerousness of the regenerative medicine.