Mutations affecting nerve attachment of Caenorhabditis elegans

Using a pan-neuronal GFP marker, a morphological screen was performed to de tect Caenorhabditis elegans larval lethal mutants with severely disorganize d major nerve cords. We recovered and characterized 21 mutants that display ed displacement or detachment of the ventral nerve cord from the body wall (Ven: ventral cord abnormal). Six mutations defined three novel genetic loc i: ven-1, ven-2, and ven-3. Fifteen mutations proved to be alleles of previ ously identified muscle attachment/positioning genes, mup-4, mua-1, mua-5, and mua-6. All the mutants also displayed muscle attachment/positioning def ects characteristic of mua/mup mutants. The pan-neuronal GFP marker also re vealed that mutants of other mua/mup loci, such as mup-1, mup-2 and mua-2, exhibited the Ven defect. The hypodermis, the excretory canal, and the gona d were morphologically abnormal in some of the mutants. The pleiotropic nat ure of the defects indicates that ven and mua/mup genes are required genera lly for the maintenance of attachment of tissues to the body wall in C. ele gans.