On Earth plants are constantly exposed to a gravitational field of 1G. Gravity affects a plant in every step of its development. Germinating seedlings orient their radicle and hypocotyl and growing plants position organs at a specific Gravitropic Set-point Angle dictated by the asymmetric distribution of auxin depending on the gravity vector. Hence gravitropism is one of the fundamental growth responses in plants. For any experiment studying the effects of gravity on plants the ultimate control is the microgravity in space. In this study Arabidopsis seeds were flown to the International Space Station and allowed to germinate and grow for 3 days in microgravity. Arabidopsis Wild Type Col-0 seeds were plated onto twenty-two 60mm Petri plates loaded into PDFUs and inserted 4 Biological Research in Canisters (BRICs). Approximately 800 seeds were sterilized plated on each 60mm Petri plates and cold stratified for 16 hours followed by 2 hours of white light treatment. The BRICs were maintained at 4C until spaceflight to ensure seed germination in microgravity. After 3 days of germination and growth the seedlings were fixed by injecting RNAlater into the chamber. They were kept at ambient temperature for 12 hours followed by freezing at -80C. An additional 22 plates were used as ground controls. After the spaceflight tissue from five plates was pooled to make each of three replicates. Both membrane and soluble proteins were extracted from the pooled seedlings. Proteins were trypsin digested labelled with iTRAQ and identified using tandem mass spectrometry.

The response of plants to the spaceflight environment and microgravity is still not well understood although there has been an increased emphasis on this topic. Even less is known about plants response to partial or reduced gravity levels. In the absence of the directional cues provided by the gravity vector the plant is especially perceptive to other cues such as light. Here we investigate the response of Arabidopsis thaliana 6-day-old seedlings to microgravity and the Mars partial gravity level during spaceflight as well as the effects of red light photostimulation by determining meristematic cell growth and proliferation. These experiments involve microscopic techniques together with transcriptomic studies. We demonstrate that microgravity and partial gravity trigger differential responses. The microgravity environment activates hormonal routes responsible for proliferation/growth and upregulates plastid/mitochondrial-encoded transcripts even in the dark. In contrast the Mars gravity level inhibits these routes and activates responses to stress factors to restore cell growth parameters only when red photostimulation is provided. This response is accompanied by upregulation of numerous transcription factors such as the environmental acclimation-related WRKY family. In the long term these discoveries can be applied in the design of bioregenerative life support systems and space farming.

On Earth plants are constantly exposed to a gravitational field of 1G. Gravity affects a plant in every step of its development. Germinating seedlings orient their radicle and hypocotyl and growing plants position organs at a specific Gravitropic Set-point Angle dictated by the asymmetric distribution of auxin depending on the gravity vector. Hence gravitropism is one of the fundamental growth responses in plants. For any experiment studying the effects of gravity on plants, the ultimate control is the microgravity in space. In this study, Arabidopsis seeds were flown to the International Space Station and allowed to germinate and grow for 3 days in microgravity. Arabidopsis Wild Type Col-0 seeds were plated onto twenty-two 60mm Petri plates, loaded into PDFUs and inserted 4 Biological Research in Canisters (BRICs). Approximately 800 seeds were sterilized, plated on each 60mm Petri plates and cold stratified for 16 hours followed by 2 hours of white light treatment. The BRICs were maintained at 4C until spaceflight to ensure seed germination in microgravity. After 3 days of germination and growth, the seedlings were fixed by injecting RNAlater into the chamber. They were kept at ambient temperature for 12 hours followed by freezing at -80C. An additional 22 plates were used as ground controls. After the spaceflight, tissue from five plates was pooled to make each of three replicates. Both membrane and soluble proteins were extracted from the pooled seedlings. Proteins were trypsin digested, labelled with iTRAQ and identified using tandem mass spectrometry.

These investigations studied the fundamentals of how plants perceive gravity and develop in microgravity. It informs how gene regulation is altered by spaceflight conditions.

Genome-wide transcriptional profiling shows that reducing gravity levels in the International Space Station (ISS) causes important alterations in Drosophila gene expression. However simulation experiments on ground without space constraints show weaker effects than space environment. A global and integrative analysis using the gene expression dynamics inspector (GEDI) self-organizing maps reveals a subtle response of the transcriptome using different populations and microgravity and hypergravity simulation devices. These results suggest that in addition to behavioural responses that can be detected also at the gene expression level the transcriptome is finely tuned to normal gravity. The alteration of this constant parameter on Earth can have effects on gene expression that depends both on the environmental conditions and the ground based facility used to compensate the gravity vector. Alternative and commons effects of mechanical facilities like the Random Positioning Machine and a centrifuge and strong magnetic field ones like a cryogenically cooled superconductive magnet are discussed. We compare the effects over the gene expression profile of different gender/age Drosophila imagoes in 3-4 days-long experiments under altered gravity conditions into three GBF (Ground Based Facilities for micro/hyper- gravity simulation) using whole genome microarray platforms. Descriptions of different GBFs (treatments): LDC means Large Diameter Centrifuge. Samples can be placed under three conditions: inside LDC (at certain g level) at the LDC rotational control and at external 1g control (outside the LDC). RPM means Random Positioning Machine. Samples can be placed under two conditions: inside RPM (at nearly 0g Microgravity level) and at external 1g control (outside the RPM). At the magnet means INSIDE the Magnetic levitator (another GBF). Samples can be placed under four conditions: inside Magnet 0g* (at microgravity with magnetic field) inside Magnet at 1g* (internal control with magnetic field) or inside the magnet 2g* (at hypergravity with magnetic field) and at external 1g control (outside the magnet)

We address a key baseline question of whether gene expression changes are induced by the orbital environment and then we ask whether undifferentiated cells cells presumably lacking the typical gravity response mechanisms perceive spaceflight. Arabidopsis seedlings and undifferentiated cultured Arabidopsis cells were launched in April 2010 as part of the BRIC-16 flight experiment on STS-131. Biologically replicated DNA microarray and averaged RNA digital transcript profiling revealed several hundred genes in seedlings and cell cultures that were significantly affected by launch and spaceflight. The response was moderate in seedlings; only a few genes were induced by more than 7-fold and the overall intrinsic expression level for most differentially expressed genes was low. In contrast cell cultures displayed a more dramatic response with dozens of genes showing this level of differential expression a list comprised primarily of heat shock-related and stress-related genes. This baseline transcriptome profiling of seedlings and cultured cells confirms the fundamental hypothesis that survival of the spaceflight environment requires adaptive changes that are both governed and displayed by alterations in gene expression. The comparison of intact plants with cultures of undifferentiated cells confirms a second hypothesis: undifferentiated cells can detect spaceflight in the absence of specialized tissue or organized developmental structures known to detect gravity.

In prospective human exploration of outer space the need to maintain a species over several generations under changed gravity conditions may arise. This paper reports the analysis of the third generation of fruit fly Drosophila melanogaster obtained during the 44.5-day space flight (Foton-M4 satellite 2014 Russia) followed by the fourth generation on Earth and the fifth generation under conditions of a 12-day space flight (2014 in the Russian Segment of the ISS). The obtained results show that it is possible to obtain the third-fifth generations of a complex multicellular Earth organism under changed gravity conditions (in the cycle weightlessness - Earth - weightlessness) which preserves fertility and normal development. However there were a number of changes in the expression levels and content of cytoskeletal proteins that are the key components of the spindle apparatus and the contractile ring of cells.

Arabidopsis were grown on horizontal or vertical clinostat for 4 8 or 12 days. Seedlings on horizontal clinostat were in simulated microgravity and seedlings on vertical clinostat are considered as a control. Comparison was made between plants grown on simulated microgravitry and vertical position. 6 dye-swap - treated vs untreated comparison

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

This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen, Candida albicans, grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 454 genes compared to synchronous ground controls, which represented 8.4% of the analyzed ORFs. Spaceflight-cultured C. albicans induced genes involved in cell aggregation (similar to flocculation), which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to more normal bipolar budding patterns for ground samples, in accordance with the gene expression data. Furthermore, genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight, including induction of ABC transporters and members of the major facilitator family, downregulation of ergosterol-encoding genes, and upregulation of genes involved in oxidative stress resistance. Finally, downregulation of genes involved in the actin cytoskeleton was observed. Interestingly, the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested, as this regulator is involved in random budding, cell aggregation, actin cytoskeleton, and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype, no increased virulence in a murine intraperitoneal (i.p.) infection model was observed. This study represents an important basis for the assessment of the risk that commensal flora could play during spaceflight missions. Furthermore, since the low fluid-shear environment of microgravity is relevant to physical forces encountered by pathogens during the infection process, insights gained from this study could identify novel infectious disease mechanisms, with downstream benefits for the general public. Cells were grown for 24 hours on the space shuttle or as ground-based controls, preserved in RNALater, and stored at -80C. Four samples of each flight- and ground-based controls were harvested for microarray analysis. GAP is Group Activation Pack and each GAP contains 8 FPAs. The numbers represent the # assigned to the particular GAP and the number assigned to the specific FPA (1-8) within the indicated GAP. The same hardware is used for the flight samples and the ground samples.