Worm Breeder's Gazette 12(3): 49 (June 15, 1992)

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 Molecular Analysis of unc-60

Camela Matheson, Kim McKim, Marcia Wakarchuk, David L. Baillie

Institute of Molecular Biology and Biochemistry, Dept. of Biological Sciences, Simon
Fraser University, Burnaby, B.C., Canada V5 A1S6

We have been cloning and sequencing the muscle gene unc-60 ,located on the left end of LGV. The genetic organization of the unc-60 region has been described previously by K. McKim (McKim et al. ,1988). Transformation rescue localized unc-60 to a deleted 22 kb cosmid, F53E2 (M. Wakarchuk, WBG Vol. 11, #1).

A restriction map of the cosmid has been constructed. Various subcloned fragments spanning the entire cosmid were used to screen a lambda Zap cDNA library (a gift from R. Barstead and R. Waterston) resulting in the isolation of cDNA clones representing two coding regions. Sequencing of cDNA and genomic clones of one of the coding regions has revealed that at least two cofilin/destrin like proteins are produced through alternate splicing. Each transcript has 5 exons, sharing only the first which is untranslated except for a single methionine residue.

Cofilin and destrin are actin binding proteins which facilitate actin polymerization and/or depolymerization. This function is consistent with the unc-60 mutant phenotype ie. disorganized thin filaments (Waterston et al., 1980).

The only lethal allele of unc-60 , s1586 ,was studied using PCR and Southern blot analysis and was shown to contain an approximately 500 bp deletion which affects both transcripts.

Currently, a 10 kb B amH1 fragment, which contains the coding regions for both cofilin/destrin like proteins, is being isolated for microinjections in an attempt to rescue unc-60 .As well, PCR products from homozygous unc-60 EMS induced mutants are being sequenced to identify their molecular nature.

Literature Cited:

McKim, K.S., M.F.P. Heschel, R.E. Rosenbluth and D.L. Baillie, 1988. Genetics 1 18:49-59.

Waterston, R.H., J.N. Thomson, and S. Brenner, 1980. Dev. Biol. 77:271-303.