Abstract
The P19 embryonal carcinoma cell line represents a pluripotential stem cell that can differentiate along the neural or muscle cell lineage when exposed to different environments. Using this cell line, we examined the expression of gap junction genes during differentiation of these stem cells into neurons and astrocytes following retinoic acid treatment. Normal, untreated P19 cells expressed two gap junction proteins, connexins 26 and 43. Neurons, the first neural cell type to develop expressed connexin26 which was detected at sites of cell-cell contact. Astrocytes developed later in culture and were detected by their expression of glial fibrillary acidic protein (GFAP). Astrocytes co-expressed GFAP and connexin43 in a similar pattern to that of primary astrocytes. These results suggest that differentiation of neural cells involves specific connexin expression in each cell type. The P19 cell line will provide a valuable model to examine the role gap junctions play during differentiation events of developing neurons and astrocytes.