New acetylcholinesterase-deficient mutants of the nematode Caenorhabditis elegans.

We have used visual screening for a mutationally induced uncoordinated phenotype, coupled with subsequent enzymatic assay, to isolate 19 new mutations producing acetylcholinesterase (AChE) deficiencies in the nematode Caenorhabditis elegans. At least 13 of these are independent, and all fall within two genes, ace-1 X and ace-2 I, previously shown to control respectively two kinetically distinct major AChE classes, A and B. Three of the 4 new ace-1 alleles and one of the 15 new ace-2 alleles are apparently leaky; the rest are probably null. For the 3 leaky ace-1 alleles, qualitative changes in the residual class A AChE strongly support the contention that ace-1 is a structural gene. In ace-2;ace-1 mutants, marked reduction in class A and B AChE reveals a third, minor, previously unrecognized AChE class, designated C.