Worm Breeder's Gazette 7(1): 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.
The touch cells die in animals carrying the dominant mutation e1611 ( Chalfie and Sulston, Devel. Biol., 82: 358-370, 1981). This mutation had been assigned as the only mutant allele of the gene mec-13 on the basis of the unique death phenotype and on somewhat shaky map data. However, recent attempts to make double mutants with e1504(mec-5) and e1497(mec-4) (by recombination with strains containing unc-7 suggested that e1611 is to the right of unc-7. It now appears that e1611 is an allele of mec-4 X. This assignment is suggested by the following data: 1) Twelve e1611/lon-2(e678) mec-4(e1497) heterozygous gave 2711 Mec, 868 Lon Mec, but no wild-type progeny. Thus, e1611 is within 0.06 map units of mec-4(e1497).2) e1611 can be reverted to a recessive mec mutation. A heterozygote strain, dpy-6(e14)e1611/szT1 was mutagenized with EMS and two of 3865 heterozygotes were wild-type (i.e. non-Mec). One of these animals no longer produced Dpys and thus probably contains a deletion (e1878) that covers e1611. The other, however, produced Dpy as wild-type progeny. The new mutation (e1879) fails to complement e1497(mec-4). Thus, e1611 is very close to and is likely to be an allele of mec-4. It is an intriguing problem how this missense mutation can lead to the selective death of the touch cells.