REVERSE GENETICS BY CHEMICAL MUTAGENESIS IN CAENORHABDITIS-ELEGANS

Traditional reverse genetics on yeast, mice and other organisms a uses homologous recombination with transgenic DNA to interrupt a target ge ne. Here we report that target-selected gene inactivation can be achie ved in Caenorhabditis elegans with the use of chemical mutagens, We us e PCR to selectively visualize deletions in genes of interest; the met hod is sensitive enough to permit detection of a single mutant among m ore than 15,000 wild types. A permanent frozen mutant collection of mo re than a million mutagenized animals has been established, and deleti on mutants of several G-protein genes were isolated from it. The appro ach is suitable to be scaled up for systematic inactivation of all 17, 000 C. elegans genes. Because it requires no transgenesis or cell cult uring, it may also be applicable to small organisms usually considered to be outside the realm of reverse genetics (for example, other nemat odes and insects), Any sequenced gene in any organism that can be hand led in Very large numbers can possibly be targeted in this way.