Arabidopsis thaliana was evaluated for its response to the spaceflight environment in three replicated experiments on the International Space Station. Two approaches were used; GFP reporter genes were used to collect gene expression data in real time within unique GFP imaging hardware and plants were harvested on orbit to RNAlater for subsequent analyses of gene expression with using Affymetrix and SAGE transcriptome analyses. Three tissue types were examined (leaves hypocotyls and roots) and compared to analyses conducted with whole plants. Transcriptome analyses with whole plants suggested that the spaceflight environment had little impact on the transcriptome of arabidopsis however closer examination of selected tissues revealed that there are a number of tissue-specific responses that arabidopsis employs to respond to this novel environment

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.

Plants exhibit a robust transcriptional response to gamma radiation which includes the induction of transcripts required for homologous recombination and the suppression of transcripts that promote cell cycle progression. Various DNA damaging agents induce different spectra of DNA damage as well as collateral damage to other cellular components and therefore are not expected to provoke identical responses by the cell. Here we study the effects of two different types of ionizing radiation (IR) treatment HZE (1 GeV Fe26+ high mass high charge and high energy relativistic particles) and gamma photons on the transcriptome of Arabidopsis thaliana seedlings. Both types of IR induce small clusters of radicals that can result in the formation of double strand breaks (DSBs) but HZE also produces linear arrays of extremely clustered damage. We performed these experiments across a range of time points (1.5-24 h after irradiation) in both wild-type plants and in mutants defective in the DSB-sensing protein kinase ATM. The two types of IR exhibit a shared double strand break-repair-related damage response although they differ slightly in the timing degree and ATM-dependence of the response. The ATM-dependent DNA metabolism-related transcripts of the xd2DSB response xd3 were also induced by other DNA damaging agents but were not induced by conventional stresses. Both Gamma and HZE irradiation induced at 24 h post-irradiation ATM-dependent transcripts associated with a variety of conventional stresses; these were overrepresented for pathogen response rather than DNA metabolism. In contrast only HZE-irradiated plants at 1.5 h after irradiation exhibited an additional and very extensive transcriptional response shared with plants experiencing extended night. This response was not apparent in gamma-irradiated plants. We treated 5-day-old WT and atm-1 seedlings of Arabidopsis thaliana with 100 Gy of Gamma radiation (over a span of 15 minutes) or 30 Gy of HZE (over a span of approximately 12 minutes). Gamma irradiations were completed at 8:40 am while HZE irradiations were conducted in two runs (due to space limitations) which were completed at 1:09 and 1:28pm respectively. Gamma treated seedlings were sampled at 10:10 am 11:40 am 2:55 pm 8:40 pm and 8:40 am. HZE treated seedlings were sampled at 2:39 pm 4:09 pm 7:24 pm 1:09 am and 1:09 pm. Un-irradiated WT and atm-1 control seedlings were sampled at 10:45 am on Day #1 and 9:15 am on Day #2. There are a total of 22 experimental or control conditions with two replicates per condition yielding 44 samples overall.

Arabidopsis thaliana was evaluated for its response to the spaceflight environment in three replicated experiments on the International Space Station. Two approaches were used; GFP reporter genes were used to collect gene expression data in real time within unique GFP imaging hardware and plants were harvested on orbit to RNAlater for subsequent analyses of gene expression with using Affymetrix and SAGE transcriptome analyses. Three tissue types were examined (leaves hypocotyls and roots) and compared to analyses conducted with whole plants. Transcriptome analyses with whole plants suggested that the spaceflight environment had little impact on the transcriptome of arabidopsis however closer examination of selected tissues revealed that there are a number of tissue-specific responses that arabidopsis employs to respond to this novel environment

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.

Interaction of COP1 and UVR8 which regulate UV-B-induced photomorphogenesis and stress acclimation in Arabidopsis thaliana.

R. rubrum S1H inoculated on solid agar rich media was sent to the ISS in October 2003 (MESSAGE-part 2 experiment). After 10 days flight R. rubrum cultures returned back to Earth. These cultures were then subjected to both transcriptomic and proteomic analysis and compared with the corresponding ground control. Whole-genome oligonucleotide microarray and high throughput proteomics which offer the possibility to survey respectively the global transcriptional and translational response of an organism were used to test the effect of space flight. Moreover in an effort to identify a specific stress response of R. rubrum to space flight ground simulation of space ionizing radiation and space gravity were performed under identical culture setup and growth conditions encountered during the actual space journey. This study is unique in combining the results from an actual space experiment with the corresponding space ionizing radiation and modeled microgravity ground simulations which lead to a more solid dissection of the different factors contribution acting in space flight conditions. Total RNA was extracted from R. rubrum S1H grown after 10 days in space flight or after 10 days in simulated ionizing radiation or simulated microgravity. Each microarray slide contained 3 technical repeats.

R. rubrum S1H inoculated on solid agar rich media was sent to the ISS in October 2003 (MESSAGE-part 2 experiment). After 10 days flight R. rubrum cultures returned back to Earth. These cultures were then subjected to both transcriptomic and proteomic analysis and compared with the corresponding ground control. Whole-genome oligonucleotide microarray and high throughput proteomics which offer the possibility to survey respectively the global transcriptional and translational response of an organism were used to test the effect of space flight. Moreover in an effort to identify a specific stress response of R. rubrum to space flight ground simulation of space ionizing radiation and space gravity were performed under identical culture setup and growth conditions encountered during the actual space journey. This study is unique in combining the results from an actual space experiment with the corresponding space ionizing radiation and modeled microgravity ground simulations which lead to a more solid dissection of the different factors contribution acting in space flight conditions. Total RNA was extracted from R. rubrum S1H grown after 10 days in space flight or after 10 days in simulated ionizing radiation or simulated microgravity. Each microarray slide contained 3 technical repeats.

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

Whole seedlings of wild type (4d) and atm mutants (4d) have been analyzed after a gamma ray irradiation of 0.75h 1.5h 3h & 5h (time course). Roots of wt (4d) atm (3d) and atr (4d) mutants have been analyzed after a 1h irradiation. Ataxia Telangiectasia Mutated (ATM) encodes a large protein with a phosphatidylinositol 3-kinase (PI3K)-like domain at the C terminus (reviewed by Rotman and Shiloh 1998). PI3K-related proteins make up a large family of Ser-Thr protein kinases numerous members of which are involved in the regulation of cell cycle progression responses to DNA damage and the maintenance of genomic stability (Hoekstra 1997). AtATM plays an essential role in meiosis and in the somatic response to DNA damage in plants similar to the function of ATM in mammals and other eukaryotes. Ataxia telangiectasia-mutated and Rad3-related (ATR) plays a central role in cell-cycle regulation transmitting DNA damage signals to downstream effectors of cell-cycle progression.