Description
We have generated “reprogrammable” transgenic mice that ubiquitously express the four Yamanaka factors in an inducible manner. Transitory induction of the transgene results in multiple teratomas emerging from a variety of organs, thus indicating that full reprogramming into iPSCs can occur in vivo. By performing bone marrow transplant experiments, we demonstrate that both hematopoietic cells, as well as non-hematopoietic cells can be reprogrammed in vivo. Remarkably, reprogrammable mice also present circulating iPSCs in the bloodstream (in vivo-iPSCs) with all the expected properties of bona fide iPSCs. Moreover, in contrast to in vitro-iPSCs or embryonic stem cells (ESCs), in vivo-iPSCs have an increased capacity to undergo trophectoderm lineage differentiation, which suggests that in vivo-iPSCs are more plastic or primitive than in vitro-generated iPSCs or ESCs. Overall design: 6 clones of in vivo-generated iPSCs, 5 indendent clones of in vitro-generated iPSCs, and 3 clones of established ESCs