Worm Breeder's Gazette 11(1): 23

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.

Mapping of the dpy-14 Gene Using Cosmid Rescue

Shiv Prasad and Ann Rose

The region of chromosome I, defined by the breakpoints of hDp19 (K.  
McKim, personal communication) and sDp2 (Rose et al, 1984), contains 
the dpy-14 gene, other visibles and at least nineteen essential genes. 
Two other duplication breakpoints, hDp58 and hDp62 (K.  McKim, 
personal communication), are located in this region and are being used 
to position the genes.
The dpy-14 region is located within a large contig on linkage group 
I (A.  Coulson and J.  Sulston, personal communication).  Within a 
portion of this region ten coding regions have been identified in 170 
kb.  of DNA flanking the polymorphisms sP1 and hP9 (Starr et al., 1989)
.  The N2/B0 polymorphic fragment sP1, which is included in the cosmid 
T21G5 has been positioned very close to dpy-14 by Starr et al.(1989).  
However, the dpy-14 gene had not been recombinationally separated from 
We have used the cosmids T13C1, T14D10 and T21G5 mixed together to 
rescue the Dpy-14 phenotype.  Rescue was achieved by microinjecting 
the cosmid DNAs into the mature oocytes of 'wild type' nematodes with 
the genotype dpy-5 y-5 p2.  One 
Dpy-5 animal indicative of dpy-14 rescue was identified in the F1 
progeny.  In the F2 both Dpy-5 and Dpy-5 were 
scored which indicated the cosmid rescue to be extrachromosomal (hEx1).
A similar attempt with the individual cosmid T13C1, which contains a 
coding region homologous to col-4 (T.  Starr, personal communication), 
did not rescue the Dpy-14 phenotype.  When the cosmid T14D10 was used 
extrachromosomal rescue of the Dpy-14 phenotype was obtained (hEx2).  
Since this cosmid does not have any homology to the collagen genes, 
dpy-14 gene is not likely to be a collagen.  The observation that the 
dpy-14 gene lies in the cosmid T14D10 has positioned the sP1 
polymorphic site to the right of dpy-14.  Four of the identified ten 
coding regions lie in the cosmid T14D10, one of which encodes the 
snRNA U1-1 (T.  Blumenthal, personal communication; T.  Starr, 
personal communication).  An attempt to rescue the Dpy-14 phenotype 
with another coding region was negative.  Therefore, we believe that 
one of two coding regions in T14D10 is the dpy-14 gene.  Attempts are 
underway to determine which of these coding regions contains the dpy-
14 gene.  This work was supported by the grant from Medical Research 
Council of Canada to AR.