| Oxidative damage is an inevitable consequence of aerobic respiration. Methionine sulfoxide reductases (Msr) are a group of enzymes that function to repair oxidized methionine residues in both free methionine and methionine in proteins. MsrA was the first of these enzymes to be discovered and is the most thoroughly studied. It is thought to play a role in both the aging process and probably several neurodegenerative diseases. I recently obtained a strain of Drosophila that was reported to have a P-element transposon located within Exon 2 (part of the open reading frame) of the eip71cd gene, which is the Drosophila homolog of MsrA. Thus, the transposon insertion should disrupt expression of the msrA gene. I did a series of experiments to "jump out" the P-element in an effort to recover two types of isogenic strains. The first would be a null mutation of the MsrA gene created by deletion of flanking genomic DNA when the P-element excised from the chromosome. The second would be a precise excision of the P-element, which would restore the genetic locus to its original structure. This study looks at the effect of a null mutant of the MsrA gene on aging and resistance to oxidative stress. |
