Stable expression of the alkaline phosphatase marker gene by neural cells in culture and after transplantation into the CNS using cells derived from a transgenic rat.

Multipotent stem cells and more developmentally restricted precursors have previously been isolated from the developing nervous system and their properties analyzed by culture assays in vitro and by transplantation in vivo. However, the variety of labeling techniques that have been used to identify grafted cells in vivo have been unsatisfactory. In this article we describe the characteristics of cells isolated from a transgenic rat in which the marker gene human placental alkaline phosphatase (hPAP) is linked to the ubiquitously active R26 gene promoter. We show that hPAP is readily detected in embryonic neuroepithelial stem cells, neuronal-restricted precursor cells, and glial-restricted precursor cells. Transgene expression is robust and can be detected by both immunocytochemistry and histochemistry. Furthermore, the levels of hPAP on the cell surface are sufficient for live cell labeling and fluorescence-activated cell sorting. Expression of hPAP is stable in isolated cells in culture and in cells transplanted into the spinal cord for at least 1 month. We submit that cells isolated from this transgenic rat will be valuable for studies of neural development and regeneration.