Worm Breeder's Gazette 9(3): 36

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.

Differential Gamete Sensitivity to Gamma-Irradiation in C. elegans

L.M. Turner, R.E. Rosenbluth and D.L. Baillie

Figure 1

Genetic analysis in the nematode Caenorhabditis 
pends on the ability to induce mutations 
using gamma-radiation. Previously a gamma-ray dose-response curve was 
obtained for self-fertilizing hermaphrodites (Rosenbluth et al. Mutat. 
Res. 110:39-48, 1985). It was found that 1500R induced recessive 
lethals in the region balanced by eT1 at a rate of 4.5%. This rate did 
not distinguish oocyte sensitivity from that of sperm. We have now 
obtained 1500R rates for hermaphrodite oocytes alone and for male 
{Figure 1}
As can be seen, in general male sperm were more sensitive than 
hermaphrodite oocytes. Furthermore the gametes appeared to be more 
sensitive in the mature rather than the immature stages. These results 
are not surprising since it was known that in Drosophila sperm are 
more sensitive than oocytes to gamma-radiation. Therefore 
consideration should be given to the gamete type and/or stage 
mutagenized when designing screening protocols.
Genetic analysis of the mutations recovered in our studies will 
determine if there are qualitative differences between mutations in 
the different gametes and stages.
Experiments are in progress which will: l) determine more precisely, 
the rates in the different oocyte stages and 2) compare the rate in 
mature sperm of hermaphrodites with that in mature sperm of males.

Figure 1