Spontaneous differentiation of porcine and bovine embryonic stem cells (epiblast) into astrocytes or neurons.

The culture of porcine or bovine epiblasts, i.e., embryonic stem cells, on STO feeder cells resulted in their spontaneous differentiation into multiple cell types that were subsequently isolated as separate cell lines. Some of these cell lines were "neuron-like" in morphology. Immunofluorescent analysis of two porcine epiblast-derived cell lines demonstrated that the cells were positive for the expression of vimentin and the glial fibrillary acidic protein (GFAP). Because of their stellate morphology and lack of neurofilament expression, it is possible that the cells are type 2 astrocytes. Similar analysis of a bovine epiblast-derived cell line showed that the cells were positive for vimentin but that they did not express GFAP. However, a few cells within the population expressed neurofilaments and alpha-internexin. It is possible that the bovine cells are neural precursor cells. The results confirm and extend the demonstrated in vitro pluripotency of porcine and bovine epiblast cultures and provide evidence for an in vitro model of embryonic neuroectoderm development.