Expression of transcription factors after short-term exposure of Arabidopsis thaliana cell cultures to hypergravity and simulated microgravity (2-D/3-D clinorotation, magnetic levitation)

Auh

et al. 2011

Planta

Seedlings of Arabidopsis thaliana (cv. Columbia) were used to evaluate dynamic transcriptional-level genome responses to simulated microgravity condition created by 3-D clinorotation. The DNA chip data analysis showed that the plant may respond to simulated microgravity by dynamic induction (up- and down-regulations) of the responsive genes in the genome. The qRT-PCR results on the investigated genes showed that the expression patterns of the genes (molecular response) were generally similar to the physiological response patterns detected in stress-challenged plants. Expression patterns were categorized into short or continual up- or down-regulated patterns, as well as stochastic changes from short- to long-term simulated microgravity stress. The induced genes are then assumed to establish a new molecular plasticity to the newly adjusted genome status in the basic milieu of maintaining homeostasis during the process of adaptation to simulated microgravity.

Section: Simulated Microgravity Treatmentmentioning

confidence: 93%

Gene expression changes in Arabidopsis seedlings during short- to long-term exposure to 3-D clinorotation

Auh

et al. 2011

Planta

“…The temperature of the bore was kept at 378C by forced air flow. Using a superconducting magnet to levitate biological organisms and material [10,11,[13][14][15] rather than a resistive magnet is attractive because we can levitate for periods much longer than can be obtained, economically, using a resistive magnet.…”

Section: Initial Hypothesismentioning

confidence: 99%

Diamagnetic levitation enhances growth of liquid bacterial cultures by increasing oxygen availability

Dijkstra

Larkin

Anthony

et al. 2010

J. R. Soc. Interface.

Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to reproduce aspects of weightlessness, on the Earth. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 h, to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture and reduces the sedimentation rate of the cells. Further experiments and microarray gene analysis show that the increase in growth rate is owing to enhanced oxygen availability. We also demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause convection during the aerobic phases of bacterial growth. We propose that this convection enhances oxygen availability by transporting oxygen around the liquid culture. Since this process results from the strong magnetic field, it is not present in other weightless environments, e.g. in Earth orbit. Hence, these results are of significance and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena.

“…These were followed by studies of levitating yeast (Coleman et al, 2007), swimming paramecia in gadolinium solution (Guevorkian and Valles, 2006b), E. coli (Dijkstra et al, 2011), cell cultures (Babbick et al, 2007;Hammer et al, 2009;Qian et al, 2009), a mouse , and Drosophila melanogaster Hill et al, 2012).…”

Section: Diamagnetic Levitationmentioning

confidence: 99%

Ground-Based Facilities for Simulation of Microgravity: Organism-Specific Recommendations for Their Use, and Recommended Terminology

et al. 2013

Research in microgravity is indispensable to disclose the impact of gravity on biological processes and organisms. However, research in the near-Earth orbit is severely constrained by the limited number of flight opportunities. Ground-based simulators of microgravity are valuable tools for preparing spaceflight experiments, but they also facilitate stand-alone studies and thus provide additional and cost-efficient platforms for gravitational research. The various microgravity simulators that are frequently used by gravitational biologists are based on different physical principles. This comparative study gives an overview of the most frequently used microgravity simulators and demonstrates their individual capacities and limitations. The range of applicability of the various ground-based microgravity simulators for biological specimens was carefully evaluated by using organisms that have been studied extensively under the conditions of real microgravity in space. In addition, current heterogeneous terminology is discussed critically, and recommendations are given for appropriate selection of adequate simulators and consistent use of nomenclature.