Worm Breeder's Gazette 11(4): 72

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.

UV Induced Mutations are Predominantly Rearrangements

Helen I Stewart, Raja E. Rosenbluth and David L. Baillie

We have found that UV irradiation of adult hermaphrodites provides a 
simple method for the induction of heritable chromosomal 
rearrangements.  A screening protocol was employed that identifies 
either recessive lethal mutations in the 40 map unit region balanced 
by the translocation eT1(III;V), or unc-36(III) duplications (see 
Stewart and Baillie 1987 CSH Meeting, p.38).  Mutations were recovered 
in 3% of the chromosomes screened after a dose of 120 J/m2.  This rate 
resembles that for 1500R gamma ray induced mutations selected in a 
similar manner.  The mutations were classified either as lethals 
[mapping to Linkage Group (LG)III or LGV] or as putative unc-36 
duplications.  In contrast to the majority of UV induced mutations 
analyzed in microorganisms, we found that a large fraction of the C.  
elegans UV induced mutations are not simple intragenic lesions, but 
are deficiencies for more than one adjacent gene or more complex 
events.  Preliminary evidence for this conclusion came from the high 
frequency of mutations that had a dominant effect causing reduced 
numbers of adult progeny.  Subsequently six out of nine analyzed LGV 
mutations were found to be deficiencies.  Other specific 
rearrangements also identified were: one translocation, sT5(II;III), 
and two unc-36 duplications, sDp8 and sDp9.Thus we believe that UV 
irradiation provides an additional tool for the analysis of C.  
elegans chromosomes.
A manuscript reporting this work has been submitted to 'Mutation