Worm Breeder's Gazette 11(1): 66
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.
Ultra-violet light, from a 30 watt germacidal lamp, was used to mutagenize d18/eT1;u46/eT1 hermaphrodite nematodes. We screened for recessive lethals in the eT1 balanced regions of LGIII(right) and LGV( left). At a U.V. dosage of 120 j/m(2), we found the rate for production of recessive lethals to be 1.3% (+/- 1.2% at the 95% confidence level). We outcrossed and recombination mapped 46 of these lethal strains. The distribution of mutational events was found to be 37% on LGIII and 63% on LGV. This distribution of hits is similar to that found for lethals induced by gamma irradiation of the same balanced region where 40% of hits are on LGIII and 60% are on LGV ( Rosenbluth et al., 1985). Of the 46 strains outcrossed, 14 lacked marker expression when tested for the presence of genetic markers, indicating the probability of complex mutational events. Eight of the recessive lethals mapping exclusively to LGV (left) have been analyzed. Five of these lethals proved to be deficiencies, sDf70, sDf71, sDf72, sDf73 and sDf74. The other three lethals are putative point mutations but may later prove to be deficiencies Two of these are alleles of previously identified genes (lin-40 and let-349) and the third identifies a new gene, let-462. The map of LGV (left), shown below, positions the 8 U.V. induced lethals. The genes in which U.V. alleles were induced are indicated by * and the newly identified gene by **. The small deficiency sDf73 deletes let-336, o not know if let-448 is to the right or the left. It is apparent, from our data, that U.V. causes a high incidence of chromosomal rearrangements such as deficiencies as well as more complex events. The spectrum of mutational events is similar to that found for gamma radiation. [See Figure 1]