International Caenorhabditis elegans Experiment First Flight-Muscle Proteins (ICE-First-Muscle Proteins) studies the correlation between proteins, muscle growth and endurance in relation to a microgravity environment. C. elegans (nematode worms) are relatively simple organisms that are used as a model for a wide variety of biological processes. The ICE-First investigation is a collaborative effort conducted by scientists from several countries which have the opportunity to work as a team to design related experiments that would produce valuable results for scientists across multiple disciplines.Principal Investigator(s)
Centre National d?Etudes Spatiales, Toulouse, , France
European Space Agency (ESA)Sponsoring Organization
Information PendingISS Expedition Duration:
October 2003 - October 2004
8,9Previous ISS Missions
The precursor to ICE-First (flown during Expedition 8), BRIC-60/C. elegans, flew on STS-107 (Columbia). Following the break-up of Columbia upon re-entry into the Earth's atmosphere, the samples were located among debris in East Texas and returned to NASA.
ICE-First-Muscle Proteins is one of several experiments that investigates the effects of spaceflight on a model organism of the nematode worm family (Caenorhabditis elegans) and aims to develop links to human physiology in space. The organism chosen for this study is known to be able to mate, reproduce and develop apparently normally during space flight. Researchers have long tried to figure out why long-term spaceflight can lead to weakened muscles in human astronauts. Many agree that microgravity conditions somehow reduce the rate at which new muscle proteins and fibers are created or synthesized. C. elegans is a round worm or nematode (Phylum Nematoda) measuring around 1mm and is found naturally in soil. Its body is composed of 959 cells and includes complete reproductive, nervous, muscular, and digestive systems. C. elegans are hermaphrodites (displaying two genders and possessing the ability of self fertilization). Its life span is about 2-3 weeks; although, concerning the liquid medium used for this study at 25°, the life cycle is around 5 days. The entire genome has been sequenced and consists of 97 million base pairs (compared to the 3,000 million found in the human genome) and around 20,000 genes (compared to the 30,000 that humans have) and an entire library of well characterized mutants are available. C. elegans has been used as a model system for various medical pathologies and was the subject of the 2002 Nobel Prize in Medicine or Physiology because the process of programmed cell death or apoptosis was first discovered while studying C. elegans development. Microgravity has an important impact on muscle physiology and growth. The muscle atrophy experienced by crewmembers while in space is well documented. C. elegans have muscles which are analogous to vertebrates including humans. In this study, the focus is on two sets of genes coding for muscle function. First, scientists will investigate the localization of Tropomodulin proteins (capping proteins found mostly in muscle cells) and other contractile proteins of muscle. In mammals, Tropomodulins display altered expression in response to muscle under- or over-loading. Worms have two Tropomodulin genes, thus the data obtained would provide preliminary results concerning the appropriateness of worms as a model for Tropomodulin involvement in muscle atrophy (Strain CC1). Second, scientists analyze the phenotype of C. elegans mutant for genes encoding protein involved in muscle survival. One such protein is Dystrophin, the product of the gene mutated in Duchêne Muscular Dystrophy, an inherited disease in which patients suffer from a progressive muscle necrosis.
The possibilities for longer-term spaceflights are increasing. These types of experiments give scientists an insight into the effect that the environment of space has on organisms down to the genetic level. This can help scientists to better understand the adverse effects that could be experienced such as muscle atrophy.Earth Applications
With certain genetic techniques used in this experiment, highlighting the genes where differences occur in comparison to Earth data can further provide scientists with a direction of where to develop research in the future, either on similar organisms or humans. By understanding fundamental processes in C. elegans, scientists can better understand the human counterparts. This study can lead to a further understanding of muscle physiology and growth.
ICE-First-Muscle Proteins samples are placed in either the Kubik Topaz or Kubik Amber incubator before and after the launch. Filming is required immediately upon the arrival on Earth for later evaluation. The samples are required to stay either frozen or refrigerated until their return to scientists in Toulouse, France two days prior to landing.Operational Protocols
The C. elegans samples are transported to the launch pad in Baikonur, transferred into the Kubik Topaz (incubator with microgravity plate) and kept at 18 degrees C. Three days after the launch, 3 samples are transferred into the Kubik Amber (incubator with centrifuge), while the other five samples remain in Kubik Topaz. On the last flight day, four of the C. elegans samples are injected with a fixative by the crew and all of the samples are placed in Kubik Topaz on the Soyuz and returned to Earth. Upon return to Earth, the containers are filmed to evaluate the behavior of the C. elegans following space flight. The small bags containing the culture of the worms are either frozen or refrigerated until they are returned to their respective principal investigators for detailed analysis, whereby scientists will study the effect of microgravity on other mutations affecting C. elegans muscle survival (including proteins MyoD, perlecan and titin). The effects of microgravity will be analyzed by immunocytochemistry (a technique used to assess the presence of a specific protein or antigen in cells) and microscopy.
Rose A, Zhao Y, Hohnsen R, Baillie D. Worms in Space? A Model Biological Dosimeter. Gravitational & Space Biology; 2005.