ESA astronaut Thomas Pesquet took this picture on 5 June 2021, during his International Space Station mission Alpha.
Thomas commented on this photo:
"What do worms and humans have in common? Apparently a lot of DNA! We just received a molecular muscle experiment involving these microscopic worms, and I installed it in Columbus yesterday. Yay science!!"
The second Molecular Muscle Experiment, MME-2, was launched to space from Cape Canaveral, USA, on 3 June 2021 with thousands of tiny C. elegans worms to live on board the International Space Station for several days to help understand spaceflight-induced muscle decline.
MME-2 continued the first experiment with similar aims to identify the molecular causes of spaceflight-induced biological changes and identify therapeutic interventions that can lessen the negative health changes caused by spaceflight.
The MME-2 scientists will investigate how spaceflight affects the combination of the nervous system and muscles signalling, and whether drugs can be used to improve health during spaceflight.
Perhaps surprisingly, C. elegans display many similarities to humans. For example, C. elegans have muscles, a gut, nerves and a circulatory system. In order to move C. elegans convert food into energy, just like humans. Genome sequencing revealed that C. elegans have around 19 000 genes, humans have around 25 000 genes. Up to 80% of the genes in C. elegans are similar to human genes. So, C. elegans is an excellent organism for studying the impacts of spaceflight on muscle health.
Space is an extreme environment, which causes many negative health adaptations to the body including the loss of muscle and bone mass. This muscle decline is so extreme that it equates to ageing 40 years in a single year of spaceflight. In order to combat the negative adaptations of muscle during spaceflight astronauts on the International Space Station exercise daily. Despite this exercise regime astronauts show visible losses in muscle function requiring weeks of rehabilitation to re-gain their muscle mass. This means that the current exercise interventions are not completely effective. We need to understand the underlying molecular causes in order to generate targeted and effective intervention strategies.