Differentiation and transformation of neural plate cells

The developmental potential of presumptive neural plate cells of prestreak chick embryos (stage 1) and neural plate cells from definitive streak chick embryos (stage 4) has been examined in cell culture using specific markers that identify the major cell types in the vertebrate central nervous system. The prestreak presumptive neural plate (PSPNP) cells, stage 1, assume an epithelial appearance in vitro and synthesize cellular fibronectin, but do not express markers for the neuronal, astrocytic, melanocytic, or oligodendrocytic lineages. Conversely, definitive-streak neural plate (DSNP) cells contain precursors which express cell-type-specific markers for terminally differentiated neurons, astrocytes, and melanocytes, and synthesize an extracellular matrix of cellular fibronectin. Differentiation of DSNP cells in vitro can be prevented by infection with a temperature-sensitive mutant of Rous sarcoma virus (RSV), tsNY68. Differentiation of DSNP cell transformants can be resumed by a temperature shift to the nonpermissive temperature. The morphological and biochemical changes associated with tsNY68 transformation are accompanied by alterations in pp60^src kinase activity in the transformed cells.