Worm Breeder's Gazette 11(2): 50
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 unc-6 gene encodes the laminin B2 chain(1). Laminin is a component of basement membranes and is composed of three chains joined by disulfide bonds. The B2 chain has six domains; two alpha-helix domains, I and II, two globular domains, VI and IV, and two domains with EGF-like repeats, V and III. Mutations in the unc-6 gene affect dorsal and ventral cell migration guidance functions(2), Using a 12kb probe containing the 5' end of the gene, restriction fragment polymorphisms have been found in DNA from three spontaneous unc-6 strains, NJ311 (rh202), NJ425(rh402), and NJ310(rh201), obtained from N2. NJ310(rh201) is a null mutation, both dorsal and ventral cell migrations are affected, whereas NJ311(rh202) and NJ425(rh402) mutations disrupt only dorsal cell guidance. The simplest interpretation of the altered restriction fragment patterns from these strains is that they contain sequences deleted as diagramed below. Presumably in both mutants with dorsal cell migration defects an in- frame deletion has removed the second (V-2) EGF-like repeat coding sequence. [See Figure 1]