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.

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.

The Rodent Reasearch-1 National Lab (RR-1 CASIS) experiment was performed to study the effect of microgravity on muscle wasting. RNA DNA and protein were purified from RR-1 CASIS (the Center for the Advancement of Science in Space) liver samples. Groups included: Flight (FLT) dissected on-orbit (21 or 22 days after launch); age-matched Ground Controls (GC); and Basal Controls (BC euthanized at time of launch). RNA-Seq whole genome BS-Seq (bisulfite sequencing) and proteomic expression profiling were performed.

Anticipating the risk for infectious disease during space exploration and habitation is a critical factor to ensure safety health and performance of the crewmembers. As a ubiquitous environmental organism that is occasionally part of the human flora Pseudomonas aeruginosa could pose a health hazard for the immuno-compromised astronauts. In order to gain insights in the behavior of P. aeruginosa in spaceflight conditions two spaceflight-analogue culture systems i.e. the rotating wall vessel (RWV) and the random position machine (RPM) were used. Microarray analysis of P. aeruginosa PAO1 grown in the low shear modeled microgravity (LSMMG) environment of the RWV compared to the normal gravity control (NG) revealed a regulatory role for AlgU (RpoE). Specifically P. aeruginosa cultured in LSMMG exhibited increased alginate production and up-regulation of AlgU-controlled transcripts including those encoding stress-related proteins. This study also shows the involvement of Hfq in the LSMMG response consistent with its previously identified role in the Salmonella LSMMG- and spaceflight response. Furthermore cultivation in LSMMG increased heat and oxidative stress resistance and caused a decrease in the culture oxygen transfer rate. Interestingly the global transcriptional response of P. aeruginosa grown in the RPM was similar to that in NG. The possible role of differences in fluid mixing between the RWV and RPM is discussed with the overall collective data favoring the RWV as the optimal model to study the LSMMG-response of suspended cells. This study represents a first step towards the identification of specific virulence mechanisms of P. aeruginosa activated in response to spaceflight-analogue conditions and could direct future research regarding the risk assessment and prevention of Pseudomonas infections for the crew in flight and the general public.

Proper interpretation of RNA sequencing data requires an understanding of assay sensitivity and sources of variability. To this end the External RNA Control Consortium (ERCC) developed a standard set of 92 poly-adenylated RNA transcripts that are orthogonal to mammalian RNA that can be added to RNA extracts before library generation and sequencing. The presence of these RNA standards at known ratios improves interpretation of RNA sequencing datasets. To test the utility of the ERCC RNA controls total RNA extracted from mouse livers from the Rodent Research 1 (flight ground control basal control and vivarium control groups) and Rodent Research 3 (flight ground control and basal control groups) missions were sequenced with and without the ERCC control RNA (RR-3 liver samples without ERCC control have been sequenced previously and the dataset is released in the GLDS-137). To allow comparison within and between groups ERCC Mix 1 or Mix 2 were added to half of the samples from each group respectively.

The Rodent Research-3 (RR-3) mission was sponsored by the pharmaceutical company Eli Lilly and Co. and the Center for the Advancement of Science in Space to study the effectiveness of a potential countermeasure for the loss of muscle and bone mass that occurs during spaceflight. Twenty BALB/c 18-weeks old female mice (ten controls and ten treated) were flown to the ISS and housed in the Rodent Habitat for 39-42 days. Twenty mice of similar age sex and strain were used for ground controls housed in identical hardware and matching ISS environmental conditions. Basal controls were housed in standard vivarium cages. Spaceflight ground controls and basal groups had blood collected then were euthanized had one hind limb removed and finally whole carcasses were stored at -80 C until dissection. All mice in this data set received only the control/sham injection. Microdissection of retinae from previously frozen eyes and RNA isolation were performed in the laboratory of Dr. Xiao Mao at Loma Linda University.

Gene expression levels were determined in 3rd instar and adult Drosophila melanogaster reared during spaceflight to elucidate the genetic and molecular mechanisms underpinning the effects of microgravity on the immune system. The goal was to validate the Drosophila model for understanding alterations of innate immune responses in humans due to spaceflight. Five containers of flies with ten female and five male fruit flies in each container were housed and bred on the space shuttle (average orbit altitude of 330.35 km) for 12 days and 18.5 hours with a new generation reared in microgravity. RNA was extracted on the day of shuttle landing from whole body animals (3rd instar larvae and adults) hybridized to Drosophila 2.0 Affymetrix genome arrays and the expression level of all genes was normalized against the gene expression level from the corresponding developmental stage animals raised on ground. Spaceflight altered the expression of larval genes involved in the maturation of plasmatocytes (macrophages) and their phagocytic response as well as the level of constitutive expression of pattern recognition receptors and opsonins that specifically recognize bacteria and of lysozymes antimicrobial peptide pathway and immune stress genes hallmarks of humoral immunity. Larval microarrays (FL 6 samples) are based on RNA extracted from 6 independent sets of 50 mid 3rd instar larvae reared in microgravity and collected on the day of landing after 12 days and 18.5 hours on the space shuttle and the same number of control larvae raised on ground (GL 6 samples). Adults microarrays (F1 3 samples) are based on RNA from 3 sets of 20 adult females each that emerged during spaceflight and within 4 hours of landing and the same number of adult females from the corresponding ground control containers (G1 3 samples).

Presented here is the environmental microbiome study of the International Space Station surfaces. The environmental samples were collected with the polyester wipes from eight different locations in the ISS during two consecutive sampling sessions (three months apart). The specific objective was to unveil the pool of genes for each location during two separate sessions to learn of functional and metabolic diversity of microorganisms in the ISS. The International Space Station (ISS) as a closed built environment has its own environmental microbiome which is shaped by microgravity, radiation, and limited human presence. The microbial diversity associated with ISS environmental surfaces was investigated during this study. Polyester wipes and contact slides were used for sampling of eight various surface locations on the ISS at different time periods. The samples were retrieved and analyzed immediately upon the return to the Earth (via Soyuz TMA-14M or Dragon capsule from SpaceX). After surface sample collection, contact slides containing nutrient media for the growth of bacteria and fungi were incubated at 25C. The polyester wipes were processed to measure microbial burden (R2A, Blood Agar, and Potato Dextrose Agar) and recover cultivable bacteria as well as fungi. Subsequently, viable microbial burden was assessed using Adenosine Triphosphate (ATP) assay, and quantitative polymerase chain reaction (PCR) methods after propidium monoazide (PMA) treatment. The 16S-tag and metagenome analyses were used to elucidate viable microbial diversity. The cultivable bacterial population yield from the polyester wipes was very high (5 to 7-logs) when compared with the contact slides (10^2 to 10^3 CFU/m2). The PMA-qPCR analysis showed considerable variation of viable bacterial population (10^5 to 10^9 16S rDNA gene copies/m2) among locations sampled. Unlike contact slides, polyester wipes cover much larger sample surface (~1 m2) and produce much more reliable results of the microbial diversity of the ISS covering both cultivable and non-cultivable species. The cultivable, total, and viable microbial diversity was determined utilizing state-of-the art molecular techniques. The implementation of the PMA assay before DNA extraction allowed distinguishing viable microorganisms, which is crucial for determining their role to the crew health, the ISS maintenance and the general knowledge of the closed environmentally controlled built systems.

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 general objective of the study was to determine modulation of gene expression by environmental factors, with a special emphasis on bone formation. For this reason, the specific period of treatment was chosen between 5-6 days post-fertilization (dpf), when bone formation and calcification are taking place. Zebrafish larvae were placed at 5 dpf into a Large Diameter Centrifuge and brought to a gravitational force of 3g or 5g for 24 hours. We show that this treatment causes a clear increase of bone formation, as illustrated by cranial skeleton staining of the bone matrix by Alizarin Red, by morphometric analysis of the resulting images and by gene expression studies of selected genes. Thus, a whole genome micro-array experiment was conducted to identify genes that may be involved in the observed effect on bone formation.