Worm Breeder's Gazette 5(1): 33

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.

Radiobiological Properties of a Strain of Free-living Nematode, R. tokai

K. Suzuki

For the last one year, we have investigated radiobiological 
properties of the strain of nematode reported in J.  Exp.  Geront.  
13: 323 (1978).  When eggs were irradiated with ultraviolet light (UV),
hatchability was reduced to about 10 per cent of that of unirradiated 
control eggs at 100 Jm(-2).  It was also found that during the process 
to hatching there is a stage exhibiting the maximum UV-sensitivity.  
In order to analyze this stage, we have visualized the whole process 
of development by 16 mm cine-film.  The work is now in progress.  
Larvae and mature nematodes were much more resistant to UV than eggs.  
For example, the average life span of 10 day-old virgin females was 
reduced to 32 per cent of that of control nematodes at 400 Jm(-2).
The nematode was also quite resistant to X-rays.  Fluence of 4 krads 
did not shorten the life span significantly.  Even at 60 krads, the 
life span was shortened by about 10 days as compared to that of 
unirradiated control animals (60 days at 30 C).  Different from the 
case of UV-irradiation, however, it was observed that various kinds of 
abnormally shaped adults were produced among X-irradiated populations 
when worms were irradiated in a larval stage.  The results led us to 
an expect that the nematode could be used as an experimental animal 
for screening teratorogenic agents including radiations.  It was also 
found that strand breaks in DNA produced by X-irradiation are 
efficiently repaired as evidenced by the sedimentation profiles in 
sucrose density gradients.