That tumor cells for all practical purposes are unstable and plastic could be expected. However, the astonishing ability of the nuclei from cells of normal adult tissues to be reprogrammed-given the right embryonic context-found its final truth even for mammals in the experiments that allowed engineering Dolly (1). The landmark experiments showed that nuclei originating from cells of frozen mammary tissues were capable of being reprogrammed by the embryonic cytoplasm and its microenvironment to produce a normal sheep. The rest is history.
展开▼
