Worm Breeder's Gazette 5(2): 29
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.
As previously reported (Cold Spring Harbor, 1979), we found that unc- 72 (e873), which had originally been positioned close to dpy-11 ( BRENNER 1974), is a dominant crossover suppressor. We now report that the regions suppressed are to the right of unc-32(III), at least upto unc-64(III), and to the left of dpy-11(V), at least upto unc-60(V). We also found that unc-67 showed no linkage to dpy-18(III) but appeared to be linked to dpy-5(I). The above crossover suppression, therefore, covers the right and left respective arms of LG III and LG V upto the most distal known markers, in each case. Segregation patterns and egg survival data from e873 heterozygotes are consistent with e873 being a translocation. The translocation has been named eT1(III;V). The recessive Unc-72 phenotype exhibited by e873 is not complemented by e251, a mutation in the unc-36(III) gene. Consistent with this, Unc-72 and Unc-36 phenotype are very similar. Thus eT1(III;V) carries a defect in unc-36. The possibility that this defect may be due to one of the breaks, makes unc-36 the putative site of an LG III breakpoint. In view of the fact that e873 is a chromosomal aberration, it is of interest to note that it was isolated after P-decay (BRENNER 1974). We hope that the identification of the crossover suppression properties, and the unc-36 allelism of e873 will make it a useful tool for the future genetic analysis of C. elegans.