Comparative Analysis of Muscle Atrophy During Spaceflight, Nutritional Deficiency and Disuse in the Nematode Caenorhabditis elegans .

While spaceflight is becoming more common than before, the hazards spaceflight and space microgravity pose to the human body remain relatively unexplored. Astronauts experience muscle atrophy after spaceflight, but the exact reasons for this and solutions are unknown. Here, we take advantage of the nematode to understand the effects of space microgravity on worm body wall muscle. We found that space microgravity induces muscle atrophy in from two independent spaceflight missions. As a comparison to spaceflight-induced muscle atrophy, we assessed the effects of acute nutritional deprivation and muscle disuse on muscle cells. We found that these two factors also induce muscle atrophy in the nematode. Finally, we identified , which encodes a calpain protease that promotes muscle atrophy. Mutants of suppress starvation-induced muscle atrophy. Such comparative analyses of different factors causing muscle atrophy in could provide a way to identify novel genetic factors regulating space microgravity-induced muscle atrophy.