Worm Breeder's Gazette 2(2): 21

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.

X-ray Induced dpy-5 Mutations: Recovery of Putative Deficiencies

A.M. Rose, D.L. Baillie

A series of dpy-5 mutations have been induced using gamma 
irradiation.  WiId type (+/+) hermaphrodites were treated with 7500R 
and mated to heterozygous males.  These males are wild type over a 
double mutant, for example ++/dpy-5 unc-13 or ++/dpy-5 unc-15.  After 
18 hours of mating individual hermaphrodites were placed on separate 
plates for 24 hours.  WiId type progeny were removed and these plates 
were screened for exceptional 'dpy' individuals in the F1.  Under 
these conditions four 'dpys' have been found.  Two more were found by 
gamma irradiating +/+ males with 6500R and crossing to homozygous 
double mutants (dpy-5 y-5 ,
000 wiId type male progeny screened, 6 hermaphrodite dpys were found, 
giving a forward mutation rate of 6/22,000 for the dpy-5 gene under 
the above conditions.  This is within a factor of 2 of the EMS rate 
proposed by Brenner for any gene (Brenner, 1974).
Each of these exceptional 'dpy's' have been tested as a putative 
deficiency.  The two generated at 6500R behaved like point mutations 
in the dpy-5 gene.  The four generated at 7500R segregate chromosomes 
which are homozygous lethal and have been named Df(I) dpy-5k2...k5.  
These appear to be affecting a lethal site as well as the dpy-5 gene.  
In none of these cases has lethal site successfully been separated 
from the dpy-5 site by recombination.  The above data suggests k2...k5 
may be X-ray induced deficiencies of the dpy-5 gene and surrounding 
region.  Further evidence that these strains carry a deficiency in the 
dpy-5 region was derived from crosses between these lines.  It is 
hoped that these deficiencies will provide a useful tool for the 
genetic analysis of this region.  This work was supported by the 
National Research Council of Canada.