J. Neurogenet13(4), 191-212

The UNC-119 family of neural proteins is functionally conserved between humans, Drosophila and C. elegans.

Morris F. Maduro*, Michael Gordon^, Roger Jacobs^, and David B. Pilgrim~

~Department of Biological Sciences, University of Alberta, Edmonton, AB Canada T6G 2E9
^Department of Biology, McMaster University, Hamilton, ON Canada L8S 4K1
*current address: Department of Molecular, Cellular, and Developmental Biology and Neuroscience Research Institute, University of California, Santa Barbara, CA USA 93106;

C. elegans animals mutant for the unc-119 gene exhibit movement, sensory and behavioural abnormalities. Consistent with a nervous system role, unc-119 reporter genes are expressed throughout the C. elegans nervous system. The UNC-119 protein has strong sequence similarity to the predicted protein from a human gene, HRG4/HsUNC-119 whose transcript is abundant in the retina. Using these similarities, we have identified a Drosphila homolog, DmUNC-119, which is expressed in the Drosophila nervous system. The predicted C. elegans, human and Drosophila gene products are conserved across two domains. Expression of portions of HRG4/HsUNC-119 or DmUNC-119, directed by the unc-119 promoter, can fully complement the C. elegans unc-119 mutant phenotype. We tested the ability of portions of HRG4/HsUNC-119 to rescue, and found that its function in C. elegans requires the conserved carboxyl terminus, while the dissimilar amino terminus is dispensable. UNC-119, HRG4 and DmUNC119 constitute members of a new class of neural genes whose common function has been maintained through metazoan evolution.