Induction of pluripotency in mammalian fibroblasts by cell fusion with mouse embryonic stem cells.

Background: Cell fusion is a phenomenon that is observed in various tissues in vivo, resulting in acquisition of physiological functions such as liver regeneration. Fused cells such as hybridomas have also been produced artificially in vitro. Furthermore, it has been reported that cellular reprogramming can be induced by cell fusion with stem cells.

Methods: Fused cells between mammalian fibroblasts and mouse embryonic stem cells were produced by electrofusion methods. The phenotypes of each cell lines were analyzed after purifying the fused cells.

Results: Colonies which are morphologically similar to mouse embryonic stem cells were observed in fused cells of rabbit, bovine, and zebra fibroblasts. RT-PCR analysis revealed that specific pluripotent marker genes that were never expressed in each mammalian fibroblast were strongly induced in the fused cells, which indicated that fusion with mouse embryonic stem cells can trigger reprogramming and acquisition of pluripotency in various mammalian somatic cells.

Conclusions: Our results can help elucidate the mechanism of pluripotency maintenance and the establishment of highly reprogrammed pluripotent stem cells in various mammalian species.