Worm Breeder's Gazette 11(5): 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.
The left end of LGIII has at last been sorted out. The mapping of fem-2 and unc-45 onto the contig had been stymied by a lack of N2/RW7000 polymorphisms in convenient places. This was overcome by looking for differences between N2 and RC301, a solution that has been used successfully by others. Several new RFLPs were found in the region where unc-45 was suspected to reside, and a new set of recombinants was constructed between N2 and RC301 over the unc-45 daf-7 intervals. Using the results from the RFLP analysis, unc-45 was found to be inseparable from one of the new polymorphisms (eP97) and injection of an unc-45(r450ts) strain with the cosmid that detected the polymorphism (W10B10) was able to rescue the Unc phenotype. The accurate positioning of unc-45 and daf-7 (whose successful rescue has been previously reported) allowed the interpolation of a position for fem-2 between eP93 and eP64, and a set of overlapping cosmids covering this region was injected (one at a time, with pRF4 as a positive control). Two of these cosmids, which overlap for about half their length based on restriction mapping, were able to rescue the Fem phenotype of fem-2(b245ts). There are several lambda clones in the region, which were isolated for a different reason, but I have not had time to test them yet. Recent genetic mapping suggests that vab-6 lies very close to the left of unc-45 (less than 15 kbp, by my calculations) and may be on the same cosmid, but this has not yet been tested by rescue. Finally, daf-7 has been successfully rescued on at least two occasions using YAC DNA that has been purified from a pulsed-field gel, without taking too much care to avoid shearing the purified DNA. One of the two rescued animals transmits the phenotype, although only to a fraction of the brood.