Experimentation on the International Space Station has reached the stage where repeated and nuanced transcriptome studies are beginning to illuminate the structural and metabolic differences between plants grown in space compared to plants on the Earth. Genes that are important in setting up the spaceflight responses are being identified; their role in spaceflight physiological adaptation are increasingly understood and the fact that different genotypes adapt differently is recognized. However the basic question of whether these spaceflight responses are required for survival has yet to be posed and the fundamental notion that spaceflight responses may be non-adaptive has yet to be explored. Therefore the experiments presented here were designed to ask if portions of the plant spaceflight response can be genetically removed without causing loss of spaceflight survival and without causing increased stress responses. The CARA experiment compared the spaceflight transcriptome responses of two Arabidopsis ecotypes Col-0 and WS as well as that of a PhyD mutant of Col-0. When grown with the ambient light of the ISS phyD displayed a significantly reduced spaceflight transcriptome response compared to Col-0 suggesting that altering the activity of a single gene can actually improve spaceflight adaptation by reducing the transcriptome cost of physiological adaptation. The WS genotype showed an even simpler spaceflight transcriptome response in the ambient light of the ISS more broadly indicating that the plant genotype can be manipulated to reduce the transcriptome cost of plant physiological adaptation to spaceflight and suggesting that genetic manipulation might further reduce or perhaps eliminate the metabolic cost of spaceflight adaptation. When plants were germinated and then left in the dark on the ISS the WS genotype actually mounted a larger transcriptome response than Col-0 suggesting that the in-space light environment affects physiological adaptation which further implies that manipulating the local habitat can also substantially impact the metabolic cost of spaceflight adaptation.

In this study transcriptome profiling was used to gain insight into the spaceflight adaptation role of Altered response to gravity-1 (Arg1) a gene known to affect gravity responses in plants on Earth. The study compared expression profiles of cultured lines of Arabidopsis thaliana derived from wild type (WT) cultivar Col-0 to profiles from a knock-out line deficient in the gene encoding (ARG1 KO) both on the ground and in space. The cell lines were launched on SpaceX CRS-2 as part of the Cellular Expression Logic (CEL) experiment of the BRIC17 spaceflight mission. The cultured cell lines were grown within 60mm Petri plates in Petri Dish Fixation Units (PDFUs) that were housed within the Biological Research In Canisters (BRIC) hardware. Spaceflight samples were fixed on orbit. Differentially expressed genes were identified between the two environments (spaceflight and comparable ground controls) and the two genotypes (WT and ARG1 KO). Each genotype engaged unique genes during physiological adaptation to the spaceflight environment with little overlap. Most of the genes altered in expression in spaceflight in WT cells were found to be Arg1-dependent suggesting a major role for that gene in the physiological adaptation of undifferentiated cells to spaceflight.

Transcriptional crosstalk between mammary gland liver and adipose tissue Experiment Overall Design: Pregnant and Lactating rats exposed to 3 gravity conditions

Cell cycle and cell proliferation are decoupled under altered gravity conditions. We have previously shown that semisolid cell cultures of Arabidopsis suffer overall genome changes in response to altered gravity and also that cell cycle stages duration is altered. By using synchronized cell cultures we will demonstrate the precise alterations in cell cycle duration and also the transcriptional signature in any of them. Experiments consists on exposures of Arabidopsis cell cultures to 1g control/simulated microgravity (RPM) conditions. Asynchronous cells exposed for 14 h + Syncronous populations choosen to have an enrichment of cell cycle phases were used (being T7/T10 samples on G2 phase T14/T16 samples on G1 phase). 6 dye-swap - time course treated vs untreated comparison.

The demands of deep space pose a health risk to the central nervous system that has long been a concern when sending humans to space. While little is known about how spaceflight affects transcription spatially in the brain, a greater understanding of this process has the potential to aid strategies that mitigate the effects of spaceflight on the brain. Therefore, we performed GeoMx Digital Spatial Profiling of mouse brains subjected to either spaceflight or grounded controls. Four brain regions were selected: Cortex, Frontal Cortex, Corunu Ammonis I, and Dentate Gyrus. Antioxidants have emerged as a potential means of attenuating the effects of spaceflight, so we treated a subset of the mice with a superoxide dismutase mimic, MnTnBuOE-2-PyP 5+ (BuOE). Our analysis revealed hundreds of differentially expressed genes due to spaceflight in each of the four brain regions. Both common and region-specific transcriptomic responses were observed. Metabolic pathways and pathways sensitive to oxidative stress were enriched in the four brain regions due to spaceflight. These findings enhance our understanding of brain regional variation in susceptibility to spaceflight conditions. BuOE reduced the transcriptomic effects of spaceflight at a large number of genes, suggesting that this compound may attenuate oxidative stress-induced brain damage caused by the spaceflight environment. This study contains data of cornu ammonis 1 region. The data of other brain regions are deposited in OSD-685 (dentate gyrus), OSD-698 (frontal cortex), and OSD-699 (cerebral cortex).

Transcriptional crosstalk between mammary gland liver and adipose tissue Experiment Overall Design: Pregnant and Lactating rats exposed to 3 gravity conditions

Astronauts have been previously shown to exhibit decreased salivary lysozyme and increased dental calculus and gingival inflammation in response to space flight host factors that could contribute to oral diseases such as caries and periodontitis. However the specific physiological response of caries-causing bacteria such as Streptococcus mutans to space flight and/or ground-based simulated microgravity has not been extensively investigated. In this study High Aspect Ratio Vessel (HARV) S. mutans simulated microgravity and normal gravity cultures were assessed for changes in metabolite and transcriptome profiles H2O2 resistance and competence in sucrose-containing biofilm media. Stationary phase S. mutans simulated microgravity cultures displayed increased killing by H2O2 compared to normal gravity control cultures but competence was not affected. RNA-seq analysis revealed that expression of 153 genes was up-regulated >= 2-fold and 94 genes down-regulated >= 2-fold during simulated microgravity HARV growth. These included a number of genes located on extrachromosomal elements as well as genes involved in carbohydrate metabolism translation and stress responses. Collectively these results suggest that growth under microgravity analog conditions promotes changes in S. mutans gene expression and physiology that may translate to an altered cariogenic potential of this organism during space flight missions. Overall design: Differential gene expression was compared between RNA from S. mutans grown in normal gravity HARVs (n=3 independent cultures) and RNA from S. mutans grown in simulated microgravity HARVs (n=3 independent cultures)

Space radiations and microgravity both could cause DNA damage in cells but the effects of microgravity on DNA damage response to space radiations are still controversial. A mRNA microarray and microRNA microarray in dauer larvae of Caenorhabditis elegans (C. elegans) that endured space xef xac x82ight environment and space radiations environment during 16.5-day Shenzhou-8 space mission were performed. In our study wild type and dys-1 mutant strains of C.elegans endured four conditions during shenzhou-8 spaceflight mission including spaceflight static condition(ss) spaceflight 1-g centrifugal condition(sc) ground control condition(gc) and no-transport control. Limited to the quantity of worm samples we performed technical-repeat test but not sample-repeat test. Accordingly eight miRNA microarrays were performed.

The effect of microgravity on gene expression in C.elegans was comprehensively analysed by DNA microarray. This is the first DNA microarray analysis for C.elegans grown under microgravity. Hyper gravity and clinorotation experiments were performed as reference against the flight experiment.

This study describes the transcriptional response of P. aeruginosa PAO1 to low-Earth orbit environmental conditions. Our aim was to assess whether the microgravity environment of spaceflight could induce virulence traits in P. aeruginosa. To this end P. aeruginosa cultures were grown in space and the expression profile was compared with ground control samples (both in biological triplicate). Characterization of bacterial behavior in the microgravity environment of spaceflight is of importance towards risk assessment and prevention of infectious disease during long-term missions. Further this research field unveils new insights into connections between low fluid-shear regions encountered by pathogens during their natural infection process in vivo and bacterial virulence. This study is the first to characterize the global transcriptomic and proteomic response of an opportunistic pathogen that is actually found in the space habitat Pseudomonas aeruginosa. Overall P. aeruginosa responded to spaceflight conditions through differential regulation of 167 genes and 28 proteins with Hfq identified as a global transcriptional regulator in the response to this environment. Since Hfq was also induced in spaceflight-grown Salmonella typhimurium Hfq represents the first spaceflight-induced regulator across the bacterial species border. The major P. aeruginosa virulence-related genes induced in spaceflight conditions were the lecA and lecB lectins and the rhamnosyltransferase (rhlA) involved in the production of rhamnolipids. The transcriptional response of spaceflight-grown P. aeruginosa was compared with our previous data of this organism grown in microgravity-analogue conditions using the rotating wall vessel (RWV) bioreactor technology. Interesting similarities were observed among others with regard to Hfq regulation and oxygen utilization. While LSMMG-grown P. aeruginosa mainly induced genes involved in microaerophilic metabolism P. aeruginosa cultured in spaceflight adopted an anaerobic mode of growth in which denitrification was presumably most prominent. Differences in hardware between spaceflight and LSMMG experiments in combination with more pronounced low fluid shear and mixing in spaceflight when compared to LSMMG conditions were hypothesized to be at the origin of these observations. Collectively our data suggest that spaceflight conditions could induce the transition of P. aeruginosa from an opportunistic organism to potential pathogen results that are of importance for infectious disease risk assessment and prevention both during spaceflight missions and in the clinic.