Worm Breeder's Gazette 11(5): 27
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.
I am interested in testing the hypothesis that one of the primary causes of aging is the accumulation of cellular damage. Previous studies have established a strong correlation between oxidative damage and aging, thus I am focusing on this type of damage. One approach is to increase the activity of an enzyme that is known to protect cells from oxidative damage via recombinant DNA technology. I have chosen to initially use the enzyme Cu-Zn superoxide dismutase (SOD) which is a primary defense against free radicals. As a first step I have cloned the C. elegans Cu-Zn SOD gene in order to increase the gene copy number by an extrachromosomal array in transgenic animals. The Cu-Zn SOD has been cloned and sequenced from several organisms and they are highly homologous. Two degenerate oligonucleotides were designed from the highly conserved regions, and the oligonucleotides were used as probes to screen S. Kim's cDNA library. Sequence analysis verified that the Cu-Zn SOD gene was isolated. An alignment of the deduced coding region is presented below. Uppercase residues denote an identity with C. elegans and at least one other organism listed. Bold residues are conserved in all fifteen eukaryotes for which protein sequence data are available. [See Figure 1] The SOD cDNA was used to determine its chromosomal location by hybridization to a YAC polytene filter (borrowed from the Horvitz lab). The SOD gene is on chromosome II near tra-2 and unc-104. I am presently analyzing existing mutants in this region to determine whether or not any are SOD mutations. Initial transgenic strains will be constructed by microinjection of the SOD gene under the control of its own promotor. These strains will be tested for increased SOD activity and their lifespan will be determined. It is expected that SOD is expressed in all cells so the promotor may be of general use. I thank A. Varshavsky, in whose laboratory the bulk of this work has been carried out, for support and helpful discussions. Supported by NIH grant to A. V. (AG08991). I also thank D. Riddle in whose laboratory the work is currently in progress.