技术资料

To understand the mechanism of the sequential restriction of multipotency of stem cells during development,we have established culture conditions that allow the differentiation of neuroepithelial precursor cells from embryonic stem (ES) cells. A highly enriched population of neuroepithelial precursor cells derived from ES cells proliferates in the presence of basic fibroblast growth factor (bFGF). These cells differentiate into both neurons and glia following withdrawal of bFGF. By further differentiating the cells in serum-containing medium,the neurons express a wide variety of neuron-specific genes and generate both excitatory and inhibitory synaptic connections. The expression pattern of position-specific neural markers suggests the presence of a variety of central nervous system (CNS) neuronal cell types. These findings indicate that neuronal precursor cells can be isolated from ES cells and that these cells can efficiently differentiate into functional post-mitotic neurons of diverse CNS structures. View Publication

Mouse embryonic stem (ES) cells cultured as aggregates and exposed to retinoic acid are induced to express multiple phenotypes normally associated with neurons. A large percentage of treated aggregates produce a rich neuritic outgrowth. Dissociating the induced aggregates with trypsin and plating the cells as a monolayer results in cultures in which a sizable percentage of the cells have a neuronal appearance. These neuron-like cells express class III beta-tubulin and the neurofilament M subunit. Induced cultures express transcripts for neural-associated genes including the neurofilament L subunit,glutamate receptor subunits,the transcription factor Brn-3,and GFAP. Levels of neurofilament L and GAD67 and GAD65 transcripts rise dramatically upon induction. Physiological studies show that the neuron-like cells generate action potentials and express TTX-sensitive sodium channels,as well as voltage-gated potassium channels and calcium channels. We conclude that a complex system of neuronal gene expression can be activated in cultured ES cells. This system should be favorable for investigating some of the mechanisms that regulate neuronal differentiation. View Publication