Worm Breeder's Gazette 14(1): 57 (October 1, 1995)
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.
Departments of Anesthesiology and Genetics, Case Western Reserve University, Cleveland, OH, 44106
Since around the turn of the century, we have been interested in the gene unc-79. Mutations in this gene alter sensitivity in C. elegans to some volatile anesthetics but not to others, which has led to the postulation of multiple sites of action for these drugs. unc-79 would then occupy an upstream position in a pathway controlling sensitivity to volatile anesthetics. unc-79 maps near the middle of chromosome III, between unc-93 and dpy-17. By mapping relative to polymorphisms we narrowed the region down to the cosmid C24F11 on the left and the gene mab-21 on the right. (King Chow had earlier shown that unc-79 was to the left of mab-21). Therefore we started to try to rescue the phenotype with cosmids in the region. Several combinations of cosmids on the left end of this region rescued the phenotype (won't bore you with details), and the common cosmid between them was C03E7. So guess what....we tried C03E7 alone and it rescued the unc-79 phenotype. At the same time we collected spontaneous unc-79 animals from a RW7097 background using a precomplimentation screen. We identified 6 new alleles of unc-79 . After 10 outcrosses 5 of these spontaneous alleles have a transposon in C03E7. One has no identifiable insertion. The flanking cosmids show no insertions. All of the insertions map to a 6.5 kb EcoR1 fragment on C03E7. Subcloning and sequencing this fragment show it to contain exclusively, and almost all of, the predicted gene, E03A3.6, identified by the sequencing project. This is a good news, bad news answer since this gene shows no overwhelming homologies to anything really neat. One interesting aside to all this, is that the first predicted intron in this gene has a bunch of telomeric sequences in it and there is at least one such sequence in the region before the first exon. Could these represent the internal sequences for meiotic lining up postulated by Ann Rose? Using these regions as a query sequence, multiple other cosmids with similar regions turn up in a homology search. They may also cause the difficulty we had obtaining a subclone of this region of the gene. Obviously, we have to prove this is the unc-79 gene. The usual cDNAs, polyA blots and rescue with small pieces containing only E03A3.6 are worked on. Things are looking up, though.