Worm Breeder's Gazette 8(3): 68

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 a 5S DNA Cluster

D. Nelson B.M. Honda

Figure 1

The recombinant phage RW70-4 (obtained from Bob Waterston) carries 4-
5 kb of Bristol (N2) genomic sequence in addition to the 1 kb 5S DNA 
repeat.  We previously reported that the 2.2 kb BamHI fragment 
immediately flanking this 5S DNA cluster is shifted to a pair of BamHI 
fragments (2.5 and 2.6 kb) in the Bergerac (BO) genome.  This RFLD was 
shown to be loosely linked to dpy-11(V).We have left-right positioned 
this RFLD with respect to several linkage group V markers as shown 
below.  The results to date confirm the linkage group V assignment and 
place this RFLD to the right of unc-76.  This correlates well with the 
in situ hybridization results placing the 5S RNA gene cluster towards 
the end of the chromosome (D.  Albertson EMBO J. 3 p1227-1234).
[See Figure 1]
While constructing the recombinant strains to complete these mapping 
experiments (still in progress), we noticed a reduction in the 
recombination distance separating dpy-21 and unc-51 in the N2/BO 
heterozygote as compared to the N2/N2 heterozygote (p=0.06 and 0.09 
respectively).  All other distances were essentially identical (ie: 
unc-76 , dpy-21).  The sample size is not yet sufficient to lend 
statistical significance to this reduction and we are repeating the 
experiment anticipating that this may reflect a small rearrangement in 
this region of the BO genome relative to the N2 standard.  Such a 
rearrangement may be related to the RFLD we have identified.

Figure 1