Effects of chronic hypoxia on Duchenne Muscular Dystrophy Drosophila melanogaster model

In order to understand the chronic hypoxia (CH) effect upon the absence of dystrophin, Drosophila melanogaster wild type and the model for DMD (dmDys), in which all dystrophins expression was knocked out by iRNA, were exposed to high altitude hypoxia (hypobaric hypoxia) during a 16-day climbing period reaching the summit of Mount McKinley (6194 meters above sea level). Furthermore, dmDys and Drosophila wild type were exposed to normobaric hypoxia (hypoxic chamber) following the same oxygen levels observed during the climbing expedition and to normoxic conditions for comparison. Affymetrix GeneChip profiling was performed for individual flies from each experimental group. CH-dmDys differentially expressed 1281 genes, whereas control group differentially expressed 57 genes. Eight heat shock protein genes detected in the CH-dmDys microarray study were down-regulated, instead of up-regulated as seen in wild type hypoxic flies. This result suggests a differential gene expression response to CH, which could affect muscle performance.These results suggest that dmDys is more sensitive to CH due to reduced muscle function and hypoxic stress response.

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