At discrete points in development, transient signals are transformed into long-lasting cell fates. For example, the asymmetric identities of two @entity2199 olfactory neurons called AWC(ON) and AWC(OFF) are specified by an embryonic signaling pathway, but maintained throughout the life of an animal. Here we show that the DNA-binding protein @entity70252 acts to convert a transient, partially differentiated state into a stable AWC(ON) identity. Expression of an AWC(ON) marker is initiated in @entity70252 loss-of-function mutants, but subsequently lost, so that most adult animals have two AWC(OFF) neurons and no AWC(ON) neurons. @entity70252 encodes a protein with distant similarity to a homeodomain. It is expressed in AWC(ON), and is an early transcriptional target of the embryonic signaling pathway that specifies AWC(ON) and AWC(OFF); its expression anticipates future AWC asymmetry. The @entity70252 protein binds a specific optimal DNA sequence that was identified through a complete biochemical survey of 8-mer DNA sequences. This sequence is present in the promoter of an AWC(OFF) marker and essential for its asymmetric expression. An 11-base-pair (bp) sequence required for AWC(OFF) expression has two activities: One region activates expression in both AWCs, and the overlapping @entity70252 -binding site inhibits expression in AWC(ON). Our results suggest that @entity70252 responds to transient embryonic signaling by repressing AWC(OFF) genes in AWC(ON), thus acting as a transcriptional selector for a randomly specified neuronal identity.

Transcriptional regulation and stabilization of left-right neuronal identity in XXXX .

@entity70252 :: ('3896760(Tax:6239)', 'Gene') :: ['NSY-7', 'nsy-7'] @entity2199 :: ('6239', 'Species') :: ['Caenorhabditis elegans']
@entity2199 :: (6239,Species) :: ['C. elegans']
