Induced pluripotent stem (iPS) cells have successfully produced mice in experiments by two independent research groups, proving that, by expression of four key transcription factors, mature cells can be reprogrammed to have a similar pluripotency to embryonic stem (ES) cells. Two groups of researchers implanted iPS cells using tetraploid embryos to create a supporting placenta and now report healthy second and third generation offspring, albeit with low success rates and high embryonic and postnatal mortality. The plasticity and the complete pluripotency of iPS cells suggest a therapeutic potential for them in many human diseases. In addition, iPS cell-derived animals provide a new tool to understand cell programming in health and disease.
Zhao X-y, Li W, Lv Z, Liu L, Tong M, Hai T, Hao J, Guo C-l, Ma Q-w, Wang L, et al. (2009). iPS cells produce viable mice through tetraploid complementation. Nature July 23 [Epub ahead of print] [doi: 10.1038/nature08267].
