Worm Breeder's Gazette 11(4): 20

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.

unc-80 is a Stupid Gene

Sue Hudson, Margaret Sedensky and Phil Morgan

Figure 1

We have been trying to clone the gene unc-80 by the method of 
transposon tagging, using advice from David Miller, Tim Schedl, Susan 
Bektesh and Alan Coulson.  We searched for spontaneously arising 
alleles in the mutator strain, RW7097.  We obtained 11 such strains, 
eight of which had spontaneous revertants.  We isolated a 3.4 kb BglII 
fragment which contains a Tc1 and correlates with the unc-80 phenotype 
1.)after 14 outcrosses, 2.)after crosses with the linked marker dpy-21,
and 3.)after a late occurring (after eight outcrosses) revertant.  
This fragment was ligated into the plasmid pBS (BamHI site) and 
labeled pCW1 (we're a real big lab) and we were happy.  Restriction 
mapping showed that the fragment contained a 300 bp region, the Tc1, 
and a 1500 bp region.  We subcloned the 300 bp fragment, the 1500 bp 
fragment and the 1800 bp fragment resulting from clipping out the Tc1 
with EcoRV (pCW2, pCW3 and pCW4, respectively--this is really 
embarrassing, maybe we should have started with pCW500).
[See Figure 1]
Alan Coulson sent us his neat YAC library which we screened with 
pCW4 and (roll of drums) it lit up one clone.  We were very happy.  
Then we identified the YAC as Y24H1 which contains part of chromosome 
II (unc-80 is on V).  We were very, very unhappy.  Then it turned out 
that Y24H1 contained more than just one YAC.  We were slightly less 
unhappy.  So we sent pCW4 to Bob Waterston, while we were probing our 
genomics with this plasmid.  Both results showed that pCW4 contained 
repetitive DNA.  About 10 YACs lit up, and the genomics showed about 
15-20 bands.  Very, very unhappy again.  However, using pCW2 and pCW3 
separately showed that pCW2 (300bp fragment) contains the repetitive 
stuff and pCW3 is a unique sequence.  We don't know at present if the 
repetitive sequences are local or widely distributed.  We are now 
sequencing both pieces and extending the cloned DNA by walking.  The 
initial sequence (only a few hundred bp) shows no homology to anything 
thus far, but is about 50% GC.  At present we are no longer suicidal.

Figure 1