Features

Worms in Space
05.06.04
Graphic of the C. elegan logo
They eat bacteria and live in your backyard. They live 2-3 weeks, and they have bodily systems just like humans. What are they? C. elegans, of course! And they are the stars of the latest voyage of the Soyuz spacecraft to the International Space Station.

Image to right: The Ice Mission - The First International Caenorhabditis elegans Experiment consists of several experiments that will investigate the effects of spaceflight on C. elegans and to develop links to human physiology
Credit: NASA


This small, soil dwelling, bacteria eating, unsegmented worm may be an important key in mankind's endeavor to explore space. Historically, the study of simple multicellular model organisms has provided crucial understanding of biological processes, ultimately leading to better understanding of human biology. The goal of this flight is to use the nematode worm Caenorhabditis elegans as a model organism for spaceflight biology.

C. elegans is a common, well-studied organism used in biomedical research as a model for human development, genetics, aging and disease. The recent award of a Nobel Prize in Medicine to three pioneering worm researchers has demonstrated the value that has been placed on the worm as a model system by the scientific and medical communities.

Photo of a C. elegan worm courtasy of Juergan Berger and Raplh Sommer, Max-Plank Institute for Developmental Biology
Image to left: C. elegans is a primitive, free living (non-parasitic) organism that shares many of the same biological characteristics that are found in humans
Credit: NASA


C. elegans is a primitive, free living (non-parasitic) organism that shares many essential biological characteristics found in human biology. The worm is conceived as a single cell that undergoes a complex process of development, starting with embryonic cleavage, proceeding through morphogenesis and growth to the adult. It has a nervous system with a 'brain' (the circumpharyngeal nerve ring), muscles and a gut. It exhibits behavior and is capable of rudimentary learning. It produces sperm and eggs, and reproduces, although normally as a hermaphrodite. After reproduction, the worm gradually ages, loses vigor and finally dies.

C. elegans can be grown in either liquid culture or on solid substrate. All 959 somatic cells of its transparent body are visible with a microscope, and its average life span in the lab is a mere 2-3 weeks. Thus, C. elegans provides the researcher with an ideal compromise between complexity and tractability.

ICE-First is an international collaboration with participants from France, Canada, Japan and the United States. Results from the NASA space flight experiment will provide an environment, notably radiation and microgravity, influence 1) worm development throughout the life cycle 2) the expression of known and novel genes by performing full genome microarray analysis 3) worm muscle physiology.

Science

Photo of three C. elegan worms
Image to right: This image shows a magnified image of 2 adult worms and 1 juvenile worm crawling in the liquid media used for the ICE mission
Credit: NASA


For the NASA component of ICE-First, worms will be grown in a chemically defined, liquid, axenic culture media referred to as C. elegans Maintenance Media (CeMM). Worms will be cultured in several collapsible gas-permeable bags for the 10 day sortie flight to the International Space Station (ISS). The culture conditions and the requirements for worm growth are well established from the ground-based studies. The life cycle from egg to egg of worms in the axenic media takes approximately 7 days and is dependent upon the temperature. Worm cultures will be maintained on an orbit at a consistent 20°C. For this experiment, live worm cultures will be returned to Earth. Immediately upon return, the movement of worms will be recorded using a microscope video system. The specimens will then be analyzed for gene expression, larval development and muscle anatomy.

Hardware

Picture of the worm's culture chamber
Image to right: Image of the worm's culture chamber. A total of four chambers were used for the flight
Credit: NASA


This experiment will be performed using hardware from the European Space Agency (ESA). The worm cultures grown in several collapsible gas permeable bags, will be placed in Type I Experimental Containers (EC1). For this experiment, the worms need to breathe air from the launch vehicle (Soyuz) and the ISS environment. A series of ventilation holes in the EC1 housing provides air exchange to the inside of the container. The vent holes will be covered with a Goretex membrane to maintain an additional level of liquid containment. The experimental containers will be placed in the Kubik incubator/cooler, maintaining the samples at 20°C. Kubik is a transportable incubator developed by ESA for the DELTA Mission to use for biological experiment processing. It is derived from former "Aquarius" incubators previously used on Soyuz to ISS flights (Andromede-2001, Odyssea-2002 and Cervantes-2003). Two units (Topaz and Amber) will be launched in the Soyuz spacecraft, and subsequently transferred and used in the Russian Segment of the ISS. Kubik Amber is equipped with a centrifuge insert, providing on-orbit 1g control and Kubik Topaz is equipped with a passive insert used solely for microgravity experiments.

For more information about this research and educational resources please visit:

Web of Live
http://weboflife.nasa.gov/

Ask a C. elegans Expert
http://weboflife.nasa.gov/celegans/index.htm

Adapted from NASA's Web of Life and Life Sciences Division