Worm Breeder's Gazette 8(3): 11

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.

Population Genetics Studies Using Rec-1

B. Rattray, A.M. Rose

Rec-1, isolated and characterized by Rose and Baillie (1979), 
produces a threefold increase in recombination frequency.   Currently 
our laboratory is investigating the spontaneous mutation frequency of 
rec-1 by using the balancing system eT1 developed by Rosenbluth and 
Baillie (1983).   Rec-1 is currently not mapped and its phenotype is 
scored by examining the recombination frequency as measured in an 
individual's progeny.   In order to have a standardized method for 
measuring 'high' versus 'low' recombination, we used the frequency of 
recombination across the dpy-5 .   Strain 
construction was accomplished in the following manner: Unc-46 
hermaphrodites were crossed with Rec-1 males.   The resulting male 
heterozygotes were crossed with Dpy-5 Rec-1 
hermaphrodites.   The progeny of this cross were dpy-5 ;
or +/+); (rec-1/rec-1 or rec-1/+).   These 
individuals were allowed to self fertilize and their progeny were 
brooded.   Crossover frequency was calculated by scoring for Dpy-5 and 
Dpy-14 progeny.   Those plates segregating Unc-46 and exhibiting an 
elevated recombination frequency were selected and Unc-46 
hermaphrodites picked ie.   unc-46/unc-46; -1.   
The above was then repeated for Dpy-18 and eT1.   The three Rec-1 
strains were then crossed using Rec-1 males to produce dpy-18 
1; -1.In addition to determining 
the spontaneous mutation frequency, one month competition experiments 
between Rec-1, wild type and various mutant populations are being run 
to determine the differences in life history traits (eg.   
developmental time, fecundity).   These data will provide initial 
values for parameters such as selection coefficients and mutation 
frequencies in future experiments.   We are beginning several long 
term experiments to study the evolutionary advantage of recombination.