Isolation and characterization of eft-1, an elongation factor 2-like gene on chromosome III of Caenorhabditis elegans

A mutation at the start codon defines the differential requirement of dpy-11 in Caenorhabditis elegans body hypodermis and male tail

dpy-11 encodes a thioredoxin-like molecule that is important for both body and male sensory ray morphogenesis in Caenorhabditis elegans. A mutant allele, s287, has a point mutation with its start codon, AUG, converted into AUA, presumably leading to null function. Since only a weak loss-of-function phenotype was observed, we tested whether an alternative start codon or the converted AUA could be used for translation initiation with reduced efficiency. Based on a functional assay of mutant phenotype complementation and biochemical analysis examining the in vivo synthesis of wild-type and mutant proteins, we conclude that AUA can be used as a less-efficient start codon for initiating translation of DPY-11. Our results also provide direct evidence that the body hypodermis and male tail of C. elegans have differential requirements of dpy-11 activity for their respective normal morphogenesis.