PLURIPOTENT EMBRYONIC STEM-CELLS FROM THE RAT ARE CAPABLE OF PRODUCING CHIMERAS

Embryonic stem cells have been enormously important in the production of targeted mutations in mice used in the study of gene function and b iological aspects of disease states. The use of these cells for mouse studies is now widespread but the production of animals from similar c ell lines derived from other species has not been previously reported. We demonstrate here the derivation of diploid rat embryonic stem cell s (RESC-01). RESC-01 cells are SSEA-1 and alkaline phosphatase positiv e, grow best on primary rat embryonic fibroblasts, and can differentia te extensively in vivo. RESC-01 cells form cystic embryoid bodies capa ble of rhythmic contractions. Rat blastocysts injected with RESC-01 ce lls form chimeras. The results indicate that the successful in vitro p ropagation and chimera production with embryonic stem cells is not lim ited to the mouse. The long-term culture of rat ES cells will provide an important resource for the study of normal physiology and disease m odels where rat is the species of choice. (C) 1994 Academic Press, Inc .