Worm Breeder's Gazette 10(2): 129
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 behavioral phenotype of unc-24 worms is characterized by severely kinked L1 worms that do not wriggle more than one quarter body length in either forward or backward directions, whereas worms from the L2 stage onward toward adults are only slightly kinked in motion and make progress similar to N2 worms. These observations appear to indicate that the unc-24 gene may be affecting the embryonic motoneurones (DAs, DBs and DDs). Reconstruction of three different alleles of unc-24 have not been consistent. The canonical allele (e138) reconstruction shows DA motoneurones to be lacking commissures to the dorsal musculature. A Tc1 allele (e2386) reconstruction contains one DA motoneurone with the same aberration but another with normal morphology. The P32 induced allele (e927) reconstruction presents DA motoneurones with normal morphologies, but the commissures of all D motoneurones (DAs, DBs and DDs) proceed toward the dorsal cord on the opposite side to the wild type condition. To clear up this ambiguity, a reconstruction of an L1 from, the canonical strain is being completed. The unc-24 gene has been isolated. A 5.6kb BamHI Tc1 containing fragment found in an allele (e2386) isolated from the TR679 strain that also shifts to a 4.0kb BamHI fragment in revertants and Bristol strains was cloned into pUC 8. A 1.0kb non-Tc1 containing fragment was isolated from this plasmid by BamHI and EcoRV digestion and was used as a probe to screen the Coulson and Sulston cosmid library. Two true positives were identified that mapped to a contig containing the vit-6 gene on linkage group IV. Fortunately, a larger cosmid in this contig which covered both newly identified cosmids had been used as an in situ hybridization probe by Rita Fishpool and Donna Albertson and showed binding to chromosome IV. The same 1.0kb non-Tc1 fragment was used to isolate 16 lambda clones from the 2a cDNA library of Julie Ahringer. The lambda inserts range in size from 0.6kb to 2.6kb. The largest of these was used as a probe and showed polymorphic band shifts on the genomic Southerns composed of different alleles of unc- 24. This insert is being sequenced.