Worm Breeder's Gazette 11(2): 58
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.
Unc-73 affects the longitudinal growth of certain neurons and the excretory cell as well as certain longitudinal cell migrations on the nematode epidermis (Hedgecock et al., Development 100, 365-382, 1987). We previously isolated unc-73(ev454) on strain RW7097 and identified a Tc1 on a 5 kb HindIII which cosegregated with this mutation in 3 factor crosses (CSH abstracts, 1989, p. 60). We have now cloned this 5 kb Tc1-containing HindIII fragment, excised the Tc1 with EcoRV, and used the flanking sequence to probe Southern blots of DNAs from unc-73( ev454) and from two independently derived spontaneous revertants of unc-73(ev454). As expected, this probe hybridized to a 5 kb HindIII fragment on the unc-73(ev454) lane and to a 3.4 kb HindIII fragment on the revertant lanes. No polymorphisms were observed in DNA from two EMS-induced alleles of unc-73 (e936 and rh40). We have obtained approximately 250 nucleotides of sequence from both ends of the 5 kb HindIII fragment. One of these ends comprises a GC rich open reading frame which fails to show any significant homology to anything in the NBRF database. We have also identified about a dozen phages from an EMBL-3 N2 genomic library (Nishiwaki and Miwa) which hybridize to our Tc1-flanking probe, but we have not yet characterized any of these. We hope that these will allow Coulson and company to identify the unc- 73-containing contig.