Worm Breeder's Gazette 14(1): 56 (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.


Shanta Sabnis, Margaret Sedensky, Phil Morgan

Depts. of Genetics & Anesthesiology, Case Western Reserve University, Cleveland, OH-44106.

         For the past few years, we have been trying (very hard) to clone
the unc-1 gene. unc-1 is one of the suppressors of the altered anesthetic
sensitivities of unc-79 and unc-80 mutants.

         Using a combination of the STS mapping technique as well as
Southern blotting, we mapped unc-1 relative to the polymorphic markers
stP41 and meP4. In each case, 100 % of the unc1nondpy3 animals were
negative for the marker and 100 % of the dpy3nonunc1 animals were positive
for it.  (We screened 100 animals for the stP41 marker and 32 for the meP4
marker.)  This result indicated that unc-1 was very close to each of these

         Initially, we had focussed our attention on the region around the
cosmid F53H8 because
   F53H8 & F35H12 detected the endpoints of fcDf1 & fcDf2 both of which
             cover unc-1;
   CO8A12 detected polymorphisms in some EMS induced unc-1 alleles; &
   None of the other cosmids in this region detected any significant
             polymorphic differences between N2 and the different unc-1

          However, despite exhaustively microinjecting cosmids from this
region, we did not see any rescue. We therefore had to accept the
possibility that fcDf1 & fcDf2 involved multiple breakpoints. We then
shifted our attention to the cosmids in the region of meP4.

          The cosmid CO4D1 rescues the kinked phenotype of an unc-1(e580)
mutant. Of 99 F1 rollers, 9 showed strong F1 rescue.Of these 9, 6 remained
stably rescued in the F2 generation. Of the other 90 nonrescued F1
rollers,12 gave stable F2 rollers, of which 2 were rescued, giving a total
of 8 stably rescued lines.  Interestingly, each of the rescued animals
also throws a varying proportion of wildtype (ie. rescued nonrolling )
animals. Some of these remain wildtype while others either express the
rol-6 marker at a later stage of development &/or give rescued roller

            Using CO4D1 as a probe, we are not able to detect any
polymorphic differences between N2 and any of the unc-1 EMS induced or
spontaneous alleles. However, when the 1.6kb Tc1 fragment was used as a
probe, we detected polymorphisms in 6 of the 10 spontaneous unc-1 alleles.
We are in the process of characterizing them further.

            Currently, our efforts are also directed towards cloning the
smallest fragment of CO4D1 that can rescue the unc-1(e580) mutant and
using that as a probe to isolate a cDNA corresponding to the unc-1 gene.