[
International Worm Meeting,
2007]
Multi-generational growth will be essential for any hope of long term human colonization of the cosmos. However, there is a lack of information about any species in space beyond three generations. In addition, trips to the Moon or Mars will result in greater exposure to space radiation, although little is known about cumulative biological effects. C. elegans provides a simple model system in which to study multi-generational growth and radiation exposure in space. Cultures of C. elegans (wt CC1 and balancer eT1 strains) were maintained on-board the ISS for periods well in excess of 3 months. Worms were grown through 10+ generations on the ISS using an automated culturing system employing defined liquid medium, commercial growth chambers, peristaltic pumps to passage worms and control instrumentation. The culturing system, the C. elegans Habitat, was housed in a temperature controlled incubator located in the ISS module Destiny. Integrated video cameras with micro lenses, combined with data downlink, were utilized to image worms for real-time assessment of larval stages, population density and movement behavior. Data analysis was performed by students at 35+ middle and high schools across the United States, Canada and Malaysia, allowing students to learn about the benefits of C. elegans research while gaining experience in the scientific method. While preliminary, data confirm what was inferred from past shorter duration spaceflight missions: growth, development, and behavior of worms are grossly unaltered during spaceflight. Changes in worm muscle that were previously observed (decreased myosin heavy chain and MyoD expression, movement defect) may reflect adaptive changes in muscle in space or may be artifacts of past culturing techniques. Planned post-flight analyses should distinguish these two possibilities. Post flight analysis of eT1 worms will determine if increased rates of genetic mutation occur with long-term exposure to space radiation. Further insights should be gained into radiation concerns for future planned interplanetary human exploration missions. In conclusion, there is no major gravity-dependent process associated with spaceflight that precludes essentially normal animal growth and development for at least ten generations in C. elegans. This work was sponsored by the National Space Agency of Malaysia (ANGKASA).