Genotypic and Phenotypic Responses of Candida albicans to Spaceflight (Micro-6) - 07.29.14
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Science Objectives for Everyone
The Genotypic and Phenotypic Responses of Candida albicans to Spaceflight (Micro-6) experiment studies how microgravity affects the health risk posed by the opportunistic yeast Candida albicans.
Science Results for Everyone
University of Colorado at Boulder, BioServe Space Technologies, Boulder, CO, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
September 2012 - March 2013
Previous ISS Missions
Increment 33/34 is the first planned mission for the Micro-6 investigation.
- When cells are exposed to spaceflight they may acquire potentially harmful properties, including increased potential for infection and increased resistance to antimicrobial compounds. A greater understanding of the effects of space flight on potentially infectious organisms is critical.
- The goal of the Genotypic and Phenotypic Responses of Candida albicans to Spaceflight (Micro-6) study is to understand the different responses and physical effects of reduced gravitational force on the yeast Candida albicans. Cells grown in microgravity are compared to cells grown in normal gravity. The team examines differences in gene expression, biofilm formation, and the susceptibility of the yeast to an antimicrobial agent.
- Understanding the different responses and physical effects of microgravity on the yeast Candida albicans may provide new insights into better management and treatment of Candida infections when they occur.
Previous studies indicate that both Candida albicans (C. albicans) and Saccharomyces cerevisiae (types of yeast) respond to low-shear (low-stress) modeled microgravity (LSMMG) with gene expression changes and morphological (structural) consequences. Gene expression is the conversion of information from a gene to a functional product that the gives rise to structural and observable changes in the organism. The goal of the Genotypic and Phenotypic Responses of Candida albicans to Spaceflight (Micro-6) study is to further examine the responses of C. albicans to microgravity by performing hypothesis-driven studies in space flight conditions. The overriding hypothesis of this study is that exposure of C. albicans to microgravity alters gene expression and morphology, consistent with a potential increase in virulence. These studies endeavor to 1) inform the value of LSMMG for predicting the physiological responses of C. albicans, 2) further explore and document the phenotypic (observable characteristic) parameters of C. albicans that are associated with pathogenicity (ability to produce infectious disease) and altered during exposure to spaceflight, and 3) predict conserved responses of higher eukaryotes (cells with a nucleus), including humans, to space flight conditions.
The Micro-6 experiment makes use of BioServe's flight certified hardware: Group Activation Packs (GAPs) stored in a Commercial Generic Bioprocessing Apparatus (CGBA). The CGBA is an incubator capable of controlling the temperature between 8ºC and 37ºC and can hold up to 16 GAPs. Each GAP holds eight Fluid Processing Apparatus (FPA) inserts. The FPA is composed of a glass barrel divided into three chambers that are separated from one another by rubber septa. Each FPA contains growth medium in the first chamber, a microbial culture suspended in stasis medium in the second chamber, and a termination reagent in the last chamber.
The fundamental space biology experiments address basic questions of how life responds to gravity and space environments.
The experiments probe the fundamental nature of life in order to enhance our understanding of how life responds to physical phenomena and physical forces on Earth and serve as the basic biological foundation in support of exploration.
Late Load L-28 hours, Early Recovery R+6 hours.
The samples will be flown up on SpaceX-1 at ambient temperature. Shortly after the GAPs have been de-stowed from the Dragon spacecraft, a crewmember will stow the GAPs in a CGBA. The CGBA will be set to the growth temperature of 30°C and then the crewmember will attach the crank to the top of the early set of GAPs and turn it to activate growth of the C. albicans. After 26 or 32 hours, depending on the sample, the crewmember will terminate the GAPs by again inserting the crank on the top of the GAP and turning. The terminated GAPs will be stored in a separate CGBA set to 4°C. Late in the Dragon docking period, a crewmember will use the crank to activate the late set of GAPs. The activated GAPs will be placed in the CGBA set to 30°C. After 26 or 32 hours, depending on the sample, a crewmember will use the crank to terminate the GAPs. The terminated GAPs will be stored in the CGBA set to 4°C. All GAPs will be stowed in Dragon spacecraft for descent and processing at the PIs labs.
Ground Based Results Publications
Searles SC, Woolley CM, Petersen RA, Hyman LE, Hyman LE, Hyman LE, Nielson-Preiss S. Modeled Microgravity Increases Filamentation, Biofilm Formation, Phenotypic Switching, and Antimicrobial Resistance in Candida albicans. Astrobiology. 2011 October; 11(8): 825-836.
Altenburg SD, Nielson-Preiss S, Hyman LE, Hyman LE, Hyman LE. Increased Filamentous Growth of Candida albicans in Simulated Microgravity. Genomics, Proteomics and Bioinformatics. 2008 January; 6(1): 42-50. DOI: 10.1016/S1672-0229(08)60019-4.
Purevdorj-Gage B, Sheehan KB, Hyman LE, Hyman LE, Hyman LE. Effects of low-shear modeled microgravity on cell function, gene expression, and phenotype in Saccharomyces cerevisiae. Applied and Environmental Microbiology. 2006 July; 76(7): 4569-4575. DOI: 10.1128/AEM.03050-05. PMID: 16820445.
Sheehan KB, McInnerney K, Purevdorj-Gage B, Altenburg SD, Hyman LE, Hyman LE, Hyman LE. Yeast genomic expression patterns in response to low-shear modeled microgravity. BMC Genomics. 2007 January 3; 8: 3. DOI: 10.1186/1471-2164-8-3. PMID: 17201921.
A Commercial Generic Bioprocessing Apparatus (CGBA) provides a controlled temperature environment for growth. The unit is pictured with 9 Group Activation Packs (GAP) that contain the C. albicans yeast.
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Fluid Processing Apparatus (FPA), in which are loaded growth media, the C. albicans microbial culture in stasis, and a termination reagent.
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Two Group Activation Packs (GAPs) each containing eight FPA Chambers.
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NASA Image: ISS033E011737 - Seven Group Activation Packs (GAP) inside of a Commercial Generic Bioprocessing Apparatus (CGBA). This CGBA was unpacked from the SpaceX Dragon vehicle, and is pictured on board the ISS Destiny Lab.
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