The neuron-restrictive silencer factor NRSF (also known as REST and XBR)
can silence transcription from neuronal promoters in non-neuronal cell lines,
but its function during normal development is unknown. In mice, a targeted
mutation of Rest, the gene encoding NRSF, caused derepression of neuron-specific
tubulin in a subset of non-neural tissues and embryonic lethality. Mosaic
inhibition of NRSF in chicken embryos, using a dominant-negative form of NRSF,
also caused derepression of neuronal tubulin, as well as of several other
neuronal target genes, in both non-neural tissues and central nervous system
neuronal progenitors. These results indicate that NRSF is required to repress
neuronal gene expression in vivo, in both extra-neural and undifferentiated
neural tissue.
