Worm Breeder's Gazette 10(2): 153
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
We have been using gamma-irradiation to induce mutations in the mec genes and ben-1 and thought we might share some of our observations. The first is that all irradiators are not alike. Although a number of people have cobalt sources, at Columbia we have a cesium source. Cesium is a weaker energy source, and we find that standard irradiation protocols are not effective. A dose of 4050 rads is needed to reduce brood size by 50%, and a dose of 8100 rads reduces it by 80%. In a screen for touch mutants, irradiating with 4050 rads, we identified 27 mutations from 180,000 mutagenized haploid genomes. These mutations mapped to the majority of the mec genes, and genes that were frequent targets with EMS also appeared to be frequent targets of gamma- rays We identified five ben-1 mutations by screening F2 progeny for benomyl resistance following irradiation with 8100 rads. The DNA from strains with these mutations has been examined by Southern blot analysis using ben-1 -tubulin DNA as a probe. Four harbor large deletions in the gene; the fifth strain seems to have a smaller deletion. Since this approach appears to be useful in generating substantial deletions within non-essential genes it should be useful in determining where genes are within contigs.