Worm Breeder's Gazette 9(1): 37

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.

Transposition of Tc1 in the Rec-1 strain of Bristol

B. Rattray and A.M. Rose

We have examined the Tc1 pattern of the Rec-1 strain of C.  elegans 
which increases recombination frequency more than three-fold for all 
intervals studied so far (Rose & Baillie, 1979 Nature 281:599; Rattray,
M.SC thesis; Rose, unpublished data).  Rec-1 DNA (prepared by N.  
Mawji in 1983), Rec-1 (1985), N2, and Unc-68(V) (spontaneous from a 
Rec-1 by N2 cross) DNA were digested with EcoRI, electrophoresed in 0.
7% agarose and blotted to nitrocellose.  The filter was hybridized 
with 32P-labelled Tc1 and autoradiographed.  Both preparations of Rec-
1 DNA gave the same result: approximately four new Tc1 bands are seen 
in the Rec-1 DNA accompanied by the loss of three or more bands that 
are present in N2.  The non-molar ratio of some bands makes it hard to 
count exactly how many changes have occurred.  Several explanations 
for the altered band pattern are possible: the bands may have been 
present in one of the Cambridge strains which were progenitors to Rec-
1 (similar to the result with CB30 presented by Carol Trent at the CSH 
Meetings); the high recombination phenotype of Rec-1 may be 
responsible for the altered banding pattern, for example gene 
conversion of Tc1 bands to Tc1(Eco) bands may have occurred; or a 
'burst' of Tc1 activity in Pec-1 may have occurred at some time in the 
past possibly coincident with the appearance of the Rec-1 phenotype.  
We observed no difference in the two preparations of Rec-1 DNA nor 
could we observe an additional band in the spontaneous mutant from the 
Rec-1 by N2 cross.  We are currently in the process of examining the 
progenitor strains for the first appearance of the altered band 
pattern and correlating these results with the timing of appearance of 
high recombination.