2018 Volume 32 Pages 6-10
Our previous spaceflight experiment CERISE showed that gene and protein expression levels of muscular components, cytoskeleton, and mitochondrial enzymes are altered in space flown wild-type C. elegans. To confirm and clarify whether the C. elegans muscle fibers and mitochondrial network are physically altered in response to microgravity, this Nematode Muscles project was designed with wild-type and several mutant lines with GFP expression. This investigation also studied whether microgravity could affect the insulin/IGF-1 (Insulin-like growth factor -1) and/or TGF-β signaling by imaging DAF-16::GFP fusion protein. Wild-type and several mutants were grown in a culture bag kept under microgravity or 1G centrifuge conditions on board ISS for 4 days starting from L1 larva. All samples were fixed on board and recovered, to be analyzed on the earth. The worms did not grow well in the μG culture bag probably due to unexpected air bubbles. Therefore, DAF-16 activation observed in larval worms in μG and not in 1G may be attributed to starvation instead of μG response. In 1G samples, we could successfully find normal mitochondrial network. We also found that chemical fixation using CFA is an effective method for preservation of GFP containing C. elegans in space environment.