The goal of this study was to assess whether low shear-modeled microgravity (LSMMG) affects yeast genomic expression patterns using the powerful tool of whole genome microarray hybridization. We determined changes in the yeast model organism, Saccharomyces cerevisisae, when grown in LSMMG using the rotating High Aspect Ratio Vessel (HARV). A significant number of genes were up- or down-regulated by at least two fold in cells that were grown for 5 generations or 25 generations in HARVs. We identified genes in cell wall integrity signaling pathways containing MAP kinase cascades that may provide clues to novel physiological responses of eukaryotic cells to the external stress of a low-shear modeled microgravity environment. A comparison of the microgravity response to other environmental stress response (ESR) genes showed that 26% of the genes that respond ,significantly to LSMMG are involved in a general environmental stress response, while 74% of the genes may represent a unique transcriptional response to microgravity. In addition, we found changes in genes involved in budding, cell polarity establishment, and cell separation that confirm our hypothesis that exposure to LSMMG causes changes in gene transcription resulting in a phenotypic response. The results of the study provide interesting clues to potential mechanisms involved in the response to, adaptation to, and survival of eukaryotic cells in a microgravity environment and our findings may have important health implications for human spaceflight. Experiment Overall Design: Four conditions are compared with three replicates each: yeast grown in low-shear modeled microgravity (HARV bioreactor) for 5 and 25 generations; yeast grown in a horizontal (non-LSMMG) HARV bioreactor for 5 and 25 generations.

This study demonstrates simulated microgravity effects on E. coli K 12 MG1655 when grown on LB medium supplemented with glycerol. The results imply that E. coli readily reprograms itself to combat the multiple stresses imposed due to microgravity. Under these conditions it survives by upregulating oxidative stress protecting genes and simultaneously down regulating the membrane transporters and synthases to maintain cell homeostasis. In this study a clinostat that mimics microgravity conditions was used to investigate the effects of microgravity on E. coli grown in LB medium supplemented with glycerol to monitor the effects on growth and global gene expression using Affymetrix DNA microarrays.

Gravity regulates the magnitude and direction of a trans-cell calcium current in germinating spores of Ceratopteris richardii. Blocking this current with nifedipine blocks the spore s downward polarity alignment a polarization that is fixed by gravity 10 h after light induces the spores to germinate. RNA-seq analysis at 10 h was used to identify genes potentially important for the gravity response. The data set will be valuable for other developmental and phylogenetic studies.

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.

Genome-wide detection of novel non-coding RNAs in S. cerevisiae by modulating an RNase P pathway through the depletion of a component RPP1. Nearly 400,000 36-mer oligonucleotide probes tiling the entire yeast genome including the mitochondrial chromosome with an average gap of 10 bases between two consecutive probes were synthesized on glass slides using a mask-less array synthesizer. RNA samples for hybridizing to the arrays were extracted from a conditional lethal allele of S. cerevisiae created by placing the RPP1 gene under control of GAL10 promoter. It allowed the expression of RPP1 in galactose-containing culture medium but suppressed its expression in glucose-containing medium. A wild-type isogenic strain was used as a control. Both strains were initially grown in galactose-containing medium and subsequently transferred and resuspended into glucose-containing medium. Eight arrays were hybridized with RNA extracted from the Rpp1-depleted cells at 0 4 7 12 16 21 30h and the control cell at 30h after initial transfer to glucose-containing medium.

Ionizing radiations are categorized by linear energy transfer (LET) into low-LET and high-LET. High-LET is considered to have a higher relative biological effectiveness (RBE) than low-LET radiations. However the details of the effects have not been clearly determined. The aim of this study was to characterize the difference between high-LET and low LET radiations. The global effects of the three types of high-LET radiations (fast neutron heavy ion (C) and thermal neutron) were compared with the low-LET radiation (gamma ray) using yeast DNA microarrays. Highly induced genes by the three types of high-LET radiations were those genes related to oxidative stress. Oxidative stress was one of the common factors associated with the four types of radiations. Oxidative stress induced by high-LET radiations may be more serious than that induced by gamma rays. Additionally genes related to protein synthesis and the ubiquitin and proteasome system were detected. This suggests that more protein damages can be induced by high-LET radiation that denatures the proteins in yeast cells. The genes specifically altered by each type of high-LET radiation were also studied. Overall design: This series contains 4 kinds of irradiation-induced gene expression profiles. Triplicates hybridization was done in each irradiation exposure and each array have high and low power scanned data respectively. All biological samples were collected independently.

The whole-genome sequences of eight fungal strains that were selected for exposure to microgravity at the International Space Station are presented here. These baseline sequences will help to understand the observed production of novel bioactive compounds.

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.

Saccharomyces cerevisiae flocculation occurs when fermentable sugars are limiting and is therefore considered as a way to enhance the survival chance of Flo-expressing yeast cells. In this paper the role of Flo1p in mating was demonstrated by showing that the mating efficiency which contributes to the increased survival rate as well by generating genetic variability is increased when cells flocculate. This was revealed by liquid growth experiments in a low shear environment and differential transcriptome analysis of FLO1 expressing cells compared to the non-flocculent wild-type cells. The results show that a floc provides a uniquely organized multicellular ultrastructure that provides a suitable microenvironment to induce and perform cell conjugation. S. cerevisiae strains BY4742 WT BY4742::FLO8 and BY4742 [FLO1] were grown in microgravity and 1-g. A transcriptomic analysis was performed and the transcriptome data were integrated with the high quality protein-protein interaction networks. The identified high score sub-networks (qvalue < 0.001) were considered and further evaluated concerning their GO enrichment using a hypogeometric test. The data were from the Ying B-1 experiment.

The data are population sizes of yeast Saccharaomyces cerevisiae growth in laboratory cultures over a period of several days with different levels of growth inhibitor cycloheximide. Our results provide rigorous experimental tests of new and old theory, demonstrating how the traditional notion of carrying capacity is ambiguous for populations diffusing in spatially heterogeneous environments.