Methionine Sulfoxide Reductase Expression in Response to Anoxic Stress Conditions in D. melanogaster

Evgeniya Rakitina

Abstract


Anoxia is condition of oxigen deprivation. Thousands of human deaths each year are attributed to events of induced anoxic conditions - ischemic strokes and heart attackes being the most numerous. But whereas mammals poorly tolerate anoxic stress, D. melanogaster endures hours of anoxia with no apparent problems. In response to anoxia, flies suppress overall energy levels and enter protective comma - spreading depression. Animals recover from comm after being returned to normal oxygen levelsb. eriod following reintroduction of oxygen is charackterized by overaundance of Reactive Oxygen Species (ROS), which oxydize vital molecules in cells. Methione is especcially susceptible to oxydation by ROS, but can be catalytically restored by enzyme Methionine Sulfoxide Reductase (Msr). Currently, little is known about the relationship between Msr activity and recovery from anoxic stress in Drosophila. Expression of Msr genes in response to anoxia is subject of this study. We use anoxia chamber to induce comma in flies, followed by Drosophila Activity Monitor to record recovery times. Our results show that signle mutant knockout flies do not take significantly longer than whildtype flies to recover from spreading depression. However, double mutants take significantly longer to recover and a greater number of Msr-deficient flies die as a result of anoxia. Failure to recover from anoxia becomes more pronounced as animals approach senescence. Protein oxidation levels are significantly increased in post-anoxic Msr double mutant flies in comparison to wildtype animals. These studies offer insight into the role of oxidative damage during reperfusion period following cardiac stroke.

Keywords


Methionine Sulfoxide Reductase; Anoxia; Drosophila; Survival Rate; Recovery Time; Spreading Depression

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