A C-ELEGANS MUTANT SCREEN BASED ON ANTIBODY OR HISTOCHEMICAL STAINING

A method has been developed for isolating mutations in Caenorhabditis elegans that alter antibody or histochemical staining patterns. The ba sis for this method is a new procedure for making C. elegans permeable that does not kill the eggs contained within the uterus of gravid adu lt hermaphrodites. A mutagenized population of gravid hermaphrodites i s made permeable and then stained with either an antibody or a histoch emical stain. Animals that stain aberrantly are picked to individual p etri plates and the eggs within the uterus of the stained mother hatch and establish a new genetic line. Antibody and histochemical stains a re especially useful phenotypes because the staining pattern will usua lly directly reflect the gene expression pattern of the gene that code s for the antigen or enzyme, This method was used to isolate mutants t hat alter the expression of a mec-7lacZ fusion gene. Transgenic animal s that contained the mec-7lacZ gene integrated into chromosome I were treated with the mutagen ethylmethanesulfonate, allowed to self-fertil ize for two generations and then stained with X-gal or antibodies agai nst beta-galactosidase. Gravid animals that stained abnormally were pi cked to fresh petri plates and their offspring were used to establish new mutant lines.