International Caenorhabditis elegans Experiment First Flight-Apoptosis (ICE-First-Apoptosis) studies the germ line development including meiotic (process of cell division that produces reproductive cells) chromosomal dynamics and germ cell apoptosis (programmed cell death) under microgravity conditions. 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)
Japan Aerospace Exploration Agency (JAXA), Tsukuba, , Japan
Japan Aerospace Exploration Agency (JAXA)Sponsoring Organization
Information PendingISS Expedition Duration
October 2003 - April 2004
8Previous 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-Apoptosis is one of several experiments that investigates the effects of space flight 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.
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°C, 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.
The ICE-First-Apoptosis investigation will examine two apoptotic processes: physiological and checkpoint apoptosis. Checkpoint apoptosis is involved in the maintenance of genomic stability through elimination of cells that have failed to repair DNA lesions. Physiological apoptosis is a common feature associated with oogenesis (the creation of an egg cell).
In C. elegans, the sequence of changes in chromosomal morphology during meiotic prophase 1, the oocyte maturation, and the germ cell apoptosis can be observed. The molecular mechanisms underlying these phenomena can be investigated with genetic approaches. For the ICE-First-Apoptosis investigation, scientists will analyze the effects of microgravity on these phenomena using the N2 wild-type and ced (cell death) mutant (ced-1) strain.
It is important for human life in space to study the effects of environmental factors during spaceflight on a number of physiological phenomena. Apoptosis plays an important role in normal multicellular development; such as the elimination of cells that have suffered DNA damage which could either lead to cancer, or heritable genetic disorders associated with germ cells. Apoptosis could be an extremely important process for the maintenance of human health on spaceflights due to the increased exposure to cosmic and solar radiation accompanied by an increase in DNA damage.Earth Applications
By understanding the cellular function processes in C. elegans, scientists can gain insight that could ultimately lead to the development of effective medical regimens for illnesses such as cancer.
ICE-First-Apoptosis samples are placed in either the Kubik Topaz or Kubik Amber incubator before and after the launch. This experiment requires 100 to 1000 animals in each strain at mixed developmental stages; in addition to 1G control of each sample in space fixed on Earth at arrival point for microscopic observations staining with DAPI (a fluorescent stain that binds strongly to DNA) and several antibodies. 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.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°C. Three days after the launch, 3 samples are transferred into the Kubik Amber, 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.
Checkpoint-induced apoptosis is involved in maintaining genomic stability through the elimination of cells that have failed to repair DNA damage. However, the occurrence of checkpoint-induced and other types of physiological apoptosis in animals during or as a result of space flight has not been documented.
Approximately 300 germ cells of C. elegans undergo apoptosis (programmed cell death) during normal development. DNA damage-induced checkpoint apoptosis also occurs in germ cells, at the meiotic pachytene nucleus stage (stage of chromosomal crossover). Results indicate that pachytene checkpoint apoptosis and physiological apoptosis in germ cells occurred normally in the space exposed nematodes. Thus, the normal occurrence of several kinds of apoptosis, including checkpoint apoptosis, during space flight supports the hypothesis that humans would retain the ability to eliminate cells that have failed to repair DNA lesions introduced by cosmic radiation during spaceflight (Higashitani 2005).
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Adachi R, Higashitani A, Kuriyama K, Higashibata A, Honda S, Honda Y, Shimazu T, Kagawa H, Higashitani N, Sasagawa Y, Ishioka N, Miyazawa Y, Szewczyk NJ, Fukui K, Conley CA, Fujimoto N. Biochemical and Molecular Biological Analyses of space-flown nematodes in Japan, the First International Caenorhabditis elegans Experiment (ICE-First). Microgravity Science and Technology. 2007; 19(5-6): 159. PMID: 19513185.
Adachi R, Tillman J, Higashitani A, Kuriyama K, Granger L, Higashibata A, Segalat L, Honda S, Gasset G, Honda Y, Kagawa H, Baillie D, Ishioka N, Fukui K, Szewczyk NJ, Conley CA, Fujimoto N, Rose A, Eche B, Chaput D, Viso M. Description of International Caenorhabditis elegans Experiment first flight (ICE-First). Advances in Space Research. 2008; 42(6): 1072 -1079. DOI: 10.1016/j.asr.2008.03.017.
Adenle AA, Johnsen R, Szewczyk NJ. Review of the Results from the International C. Elegans First Experiment (ICE-FIRST). Advances in Space Research. 2009; 44(2): 210-216. DOI: 10.1016/j.asr.2009.04.008. PMID: PMC2719817.
Rose A, Zhao Y, Hohnsen R, Baillie D. Worms in Space? A Model Biological Dosimeter. Gravitational & Space Biology; 2005.