Worm Breeder's Gazette 10(1): 99
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.
To get familiar with C. elegans, I did some genetics, and generated in particular a map of the centre of the X. [See Figure 1] Note the new position of vab-3, and the allelism of unc-27 and unc- 99. Genes seem to cluster in the dpy-7 to vab-3 interval. The only previously known allele of unc-110, e1913, is a dominant Unc resembling unc-93 and a recessive larval lethal. A dosage series of unc-110, using nDf-19, stDp-2 or triplo-X was constructed. Interestingly, the phenotypes of the hermaphrodites could be ordered [See Figure 1] e1913 is therefore an antimorphic allele whose phenotype is an accurate representation of the dosage. It is also dosage compensated : unc/+;tra-1 males have an Unc phenotype similar to unc/+ hermaphrodites and do mate, whereas unc/0;stDp-2(X,IIC)[unc-110+] are extreme Uncs and are sterile. Incidently, this would make unc-110 ( e1913) a good tool for selecting mutants that modify dosage compensation in either direction. In a search for amorphic alleles of unc-110, 5 independent revertants (in 501 progeny from 74) were collected after EMS treatment. Four were inseparable from e1913 and are probably amorphs. They are homozygous viable and nearly wild type; that the unc-110 gene product appears to be redundant. Primarily interested in the building of the nervous system, I also mapped nine pseudo-spontaneous unc alleles isolated by R. Hoskins, J. Mancillas, L. Nawrocki and me. To my surprise, four of them defined new unc loci : unc-115 : strong kinker, amorph, XC, between unc-58 and vab-3,unc- 116 : L1 coiler, hypomorph, IIIC, 0.06u to the right of unc-86, in the unc-86 contig. unc-117 : larval kinker, XL, <0.2u from unc-20.unc-118 : kinker, XC, between unc-90 and unc-58. The amorph, if viable, is probably sterile. High number uncs should not be despised. unc-116 (e-2310), isolated by J. Mancillas, has a number of cell nuclei mispositioned in the L1. The hyp7 contralateral nuclear migration is impaired in the very same manner as in unc-83 and unc-84, and the hyp7 nuclei lie in the dorsal hypodermal ridge. Electron microscopy also shows some variable mispositioning of a number of lateral axons. In one animal out of three, one ALM runs in the dorsal cord, as noticed by Nichol Thomson.