Identification and cloning of unc-119, a gene expressed in the Caenorhabditis elegans nervous system.

A spontaneous mutation affecting locomotion of the nematode Caenorhabditis elegans has been mapped to a new gene, unc-119. Phenotypic characterization of the mutants suggests the defect does not lie in the musculature and that the animals also have defects in feeding behavior and chemosensation. unc-119 has been physically mapped relative to a previously identified chromosomal break in linkage group III, and DNA clones covering the region can rescue the mutant phenotype in transgenic animals. Three more alleles at the locus, with identical phenotypes, have been induced and characterized, all of which are putative null alleles. The predicted UNC-119 protein has no significant similarity to other known proteins. Expression of an unc-119/lacZ fusion in transgenic animals is seen in many neurons, suggesting that the unc-119 mutant phenotype is due to a defect in the nervous system.