Worm Breeder's Gazette 5(1): 18b
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.
While screening for chromosome rearrangements that will act as crossover suppressors, we have picked up several X-ray-induced male- throwing mutants, some of which we have begun to study. We now have in stock ten independent mutants that have been backcrossed three times. They segregate about 10-40% males. The mutations responsible for male-throwing are all X-linked and dominant and are all transmissible by males. Some mutations are in fact translocations; for example, mnT2(II;X) heterozygotes throw 39% males, about half of which carry mnT2. The mnT2-bearing males can transmit either mnT2 or a half-translocation, which fails to complement unc-1 X (but does complement dpy-3, unc-6, ecessive lethal, but which still promotes male-throwing. Other dominant Him mutations appear to reside solely on the X. Some of the mutations (including mnT2) greatly suppress recombination on the X--as measured by the widely-spaced markers dpy-3 and unc-3--but others seem to have little effect on X recombination. We do not know whether or not any of the mutant X chromosomes are mitotically unstable. We have only a few mutations in homozygotes; the homozygotes in hand also segregate males at high frequency.