MutT enzymes prevent DNA damage by hydrolysis of 8-oxodGTP, an oxidized 
substrate for DNA synthesis and antimutagenic, anticarcinogenic, and 
antineurodegenerative functions of MutT enzymes are well established. MutT has 
been found in almost all kingdoms of life, including many bacterial species, 
yeasts, plants and mammals. However, a Caenorhabditis elegans MutT homologue was 
not previously identified. Here, we demonstrate that NDX-4 exhibits both 
hallmarks of a MutT-type enzyme with an ability to hydrolyze 8-oxodGTP and 
suppress the Escherichia coli mutT mutator phenotype. Moreover, we show that 
NDX-4 contributes to genomic stability in vivo in C. elegans. Phenotypic 
analyses of an ndx-4 mutant reveal that loss of NDX-4 leads to upregulation of 
key stress responsive genes that likely compensate for the in vivo role of NDX-4 
in protection against deleterious consequences of oxidative stress. This 
discovery will enable us to use this extremely robust genetic model for further 
research into the contribution of oxidative DNA damage to phenotypes associated 
with oxidative stress.