SpaceBiology 1

Gilles Clément

Space Biology

Research on Cells,Animals, and Plants

in Space

International Space UniversityStrasbourg, France

SpaceBiology 2Lecture Outline

• What is Life? Evolution of Life. Life on Mars

• The effects of gravity on cell shape and function.Gravitational Biology

• The effects of spaceflight on development of animals.Development Biology

• The effects of spaceflight on plants. Plant Biology

• Biotechnology in microgravity

• The biological research facilities on board the International Space Station

Water droplets on a planton board the ISS (NASA)

SpaceBiology 3The Evolution of Cell

• Living cells arose on Earth by the spontaneous aggregation ofmolecules about 3 ½ billion years ago

– These early (prokaryotic) cells (e.g. bacteria) are small, withrelatively simple internal structures containing DNA, proteinsand small molecules

– They replicate quickly by simply dividing in two (a single cell can divide every 20 min. and thereby give rise to 5 billion cells in < 11 hours). ⤶⤷Their ability to divide quickly (growth rate) enables these cells to adapt rapidly to changes in their environment

– Bacteria can utilize virtually any type of organic moleculeas food (including sugars, amino acids, fats, hydrocarbons,...)and get their energy (ATP) from chemical processesin absence or presence of Oxygen

SpaceBiology 4Speaking about Contamination

• The Apollo-12 LunarModule landed on the Moon156 meters away fromSurveyor-3, which landedthere 2 ½ years earlier

• The astronauts recovereda camera of the Surveyorspacecraft for analysisback on Earth

• Specimen of a bacteria(Streptococcus mitis oralis)were still alive on thecamera

SpaceBiology 5The Worldʼs Oldest Living Thing

• Spores of the Bacillus bacteria were foundduring the summer of 2000 in salt crystalsburied 600 meters below ground at a cavernin New Mexico, US

• When they were extracted from the crystalsin a laboratory and placed in a nutrientsolution, the micro-organisms revived andbegan to grow

• These bacteria have survived in a state of suspended animation for 250 million years

• Until then, the worldʼs oldest living survivors were thought to be 25-40 million year old bacteria sporesdiscovered in a bee preserved in amber

SpaceBiology 6The Evolution of Cell

• About 1 ½ billion years ago appeared larger and more complexcells such as those found in higher animals and plants

– These eukaryotic cells (or protozoa) have a nucleus whichcontains the cellʼs DNA, and a cytoplasm where most of thecellʼs metabolic reactions occur

– They get their ATP from aerobic oxidation of food molecules(respiration) or from sunlight (photosynthesis)

SpaceBiology 7Evolution of Organisms

(deduced from their genes sequences)

E. coli (causes food poisoning)Strepococcus pyrogenes (causes strep throat)Mycobacterium tuberculosis(causes tuberculosis)

Giardia intestinalis (causes diarrhea)Trypanosoma brucei (causes sleeping sickness)Plasmodium gametocyte(causes malaria)

Histoplasma capsulatum(causes lung infection)Penicillium notatum (producesthe drug penicillin)

yeast (one-celled)mushroom (multi-celled)

extremophilesSulfolobus

vertebratesinvertebratesplants

fungi

protista

archaebacteria

eubacteria

protozoa (multi-celled)

rattoadshrimpmaize

SpaceBiology 8Life on Mars• This 4 ½ billion-year-old rock is a

portion of a meteorite (ALH84001)that was dislodged from Mars andthat fell to Earth in Antarctica about16 million years ago

• It is believed to contain fossilevidence that primitive life mayhave existed on Mars more than3 1/2 billion years ago

High-resolution scanning electronmicroscope images of AHL84001

Possible microscopicfossils of bacteria-like

organisms

SpaceBiology 9Gravitational Biology

• How cells, as single unicellular organisms, or as the basicunit of multi-cellular organisms, are sensitive to gravity?

• Studies of the effects of gravity on:– Cell Morphology

• Shape• Structure (skeleton)• Polarization (up-down orientation)

– Cell Function• Secretion• Transportation of substances

in and out the cell• Immune response

– Cell-Cell Interaction• Communication• Differentiation

SpaceBiology 10Results of Space Experiments• Bacteria

– Increase in growth rate (proliferation)– Increased resistance to antibiotics

Colonies ofbacteria (Bacillussubtillus) culturedon board Skylab

Bacteria grownunder the sameambient conditionsas Skylab, but onEarth

SpaceBiology 11Results of Space Experiments• Human Cells

– Space anemia– Resistance to

bacteria or virus isaltered

Red Blood Cells

Platelet

White Blood Cell

Blood draw kit

SpaceBiology 12Human Cells in Space

• Reduction in the number of red bloodcells (space anemia)

– Red blood cells carry the oxygento the muscles

– The reduction in plasma volume(due to fluid loss) causes an over-abondance of oxygen-carryingcapability

– Muscles lose mass and requireless oxygen

– This over-abondance of oxygen isdetected by the kidneys

– The kidneys reduce the production ofan hormone (erythropoietin, EPO)which, in turn, decreases red blood cell formation

Plasma (55%)

White blood cellsRed blood cells

SpaceBiology 13Human Cells in Space (contʼd)

• Resistance to bacteria or virus is altered (immune reaction)

– Lymphocytes produce antibodies which counteract the invading body

– Activation of lymphocytes in-vivo is depressed after spaceflight

– Lymphocytes can be purified from blood and activated by exposure to various substances in culture (in vitro)

– Lymphocytes activation in-vitro is reduced by 90% in-flight(probably due to changes in membrane structure)

– However,T-lymphocytes activation in-vitro in space isaccompanied by an increase in secretion of interferon(a molecule which interferes with virus growth)

– Use of space for synthesis of biomolecules (biotechnology)

viruses

microbes

SpaceBiology 14Development Biology

• After fertilization of the amphibian eggs, two rotations occur :– The whole egg detaches from its jelly

capsule and rotates on itself so that the heavier vegetative pole moves downwards

– An hour or so later, just the egg cortex rotates by 30° relative to the cytoplasm. This rotation establishes the dorso-anterior axis and depends on a transient array of parallel microtubules at the vegetal cortex

• Very roughly, the animal pole corresponds to the head, and the vegetal pole corresponds to the dorsal side

SpaceBiology 15Amphibian Development

When the cortex does notrotate normally, the embryofails to develop

Cortex rotation:The cytoplasmrotates with respectto the overlyingcortex by about 30degrees. The gray crescent isonly visible incertain amphibianeggs

SpaceBiology 16Embryonic Development

The early stages areclosely similar amongspecies (drawn toscale)

The later stages aremore divergent (notdrawn to scale)

Fish Salamender Chick Human

SpaceBiology 17Development in Space

• Invertebrates– Aquatic species less susceptible to

microgravity than terrestrial species• Fertilization and larval development

normal in sea urchin eggs• Formation of skeletal hard parts

(shells, spicules) which involvecalcium carbonate is altered duringdevelopment in microgravity

– Insects:• Development abnormalities in

drosophilas bred in space• Stick insect: reduced hatching rate of

eggs, but embryonic developmentbefore hatching showed no majormorphological anomalies

Note: Fish is a vertebrate

SpaceBiology 18Invertebrates in Space

Spiders use both the wind andgravity to determine the

required thickness of webmaterial

First web built in space

SpaceBiology 19Development in Space (contʼd)• Vertebrates

– No vertebrates have been raised from conception to sexual maturity in space

– No birds or reptiles have bred in orbit– Fertilized chicken and quail eggs have flown: few young chick

embryos have survived; normal development of eggs launchedat later developmental stages.

– Frog eggs fertilized inflight:• Differences in early

embryogenesis• But tadpoles at feeding

stage are not different from controls

Therefore, rotation of egg is not only gravity-driven. It presumably depends on a transient array of microtubules.The major embryonic axis forms independently of gravity

Ground

Flight

SpaceBiology 20Development in Space (contʼd)

• Vertebrates (contʼd)– Tadpoles born in space have difficulties

to inflate their lungs in microgravity– Tadpoles born in space exhibit larger

visual-oriented responses during 9 days postflight– Fish (Medaka) larvae raised in space swim normally when

tested on Earth (Ijiri,1997)

SpaceBiology 21Development in Space (contʼd)

• Vertebrates (contʼd)– The Dorsal Light Response (DLR) of fish is a simple model

of visual-vestibular control of posture– On Earth, the DLR is amplified in fish with no otoliths– In microgravity, the DLR is dominant in most animals

Carp with otoliths of the vestibular system removed on Earth

Normal carp on Earth

Arrow show the direction of coming light

SpaceBiology 22Development in Space (contʼd)

• Mammals– Flown pregnant rats gave birth to normal neonates

after flight– During postflight delivery, flight dams have twice as many

abdominal contractions as the ground controls– Flown neonate rats show persistent slower weight-bearing

behaviors (walking, surface righting) postflight. Therefore,gravity is required for critical developmental periods

Walking/righting of neonates rats in 0-GThe Neurolab mission was

16-day long

SpaceBiology 23Behavioral Studies in Space

• Little neurobehavioral research has been done inmicrogravity with vertebrates, juvenile or adult

• On Earth, jellyfish normally float upright, and pulse theirmantles upward. In 0-g they were either quiet or pulsed inlarge loops

• On board Skylab, killifish first swam in somersaults' loopsand spirals. 18 days later, they had ceased to swimerratically, and relied on light as a indication of up anddown

• In 0-g during parabolic flight, pigeons flap their wings androtate in place without any forward motion. They do notseem to have any ability to control their flying behavior

• Quail chicks were hatched on Mir. If held in a cosmonaut'shand, they would not be bothered by 0-g and peck food.When turned loose, they rapidly rotated and madesomersaults, loops, and spirals

SpaceBiology 24Space Research in Plant Biology

• Mechanism of gravity perception (gravitropism)

• Development of closed ecological life support systems

• Plants respond to environmental stimuli such as light (phototropism), water (hydrotropism), and magnetic or electric fields. These responses are masked on Earth by the overriding response of plants to gravity

• Role of the absence of 24 hour cycles in light and temperature on circadian rhythms in plants. The generation of the circadian rhythms is likely to involvethe membrane transport systems, and these systems areaffected by microgravity

SpaceBiology 25Gravity Perception in Plants

Plants have gravity-sensing organs in their roots, whichinvolve the sedimentation of particles (statoliths)

When the root is placedhorizontally for 3 hours, thestatoliths are now sedimentedonto the lateral walls of the cell

On Earth, in aroot placedvertically, thestatoliths (blackparticles) aresedimented atthe bottom endof the cell

Zea maize root cap

SpaceBiology 26Gravity Perception in Plants

• Is it the movement of the statolithsthrough the cytoplasm, or thepressure they exert on other (lower)cellular components, that is involved ingraviception?

• What is the threshold for gravityperception?

Removal of the root abolishes the capacity to detect gravity

Zea maize

SpaceBiology 27Plant Development in 0-g

0-G Effects

Changes in orientationof stem and leaves

More adventilious rootsFaster growth ofsecondary rootsChanges in orientationof secondary rootsReduction of the primaryroot growthLoss of apicaldominance

From Perbal (2001)

1-G 0-G

apical stemleaf

axillary bud

stem adventilious roots

secondary root

primary root

root cap

SpaceBiology 28

Adapted from G. Perbal (1992)

Roots grow randomly in 0-g,but can be reoriented uniformly on

exposure to 1-g for as little as 3 hours

0-g

On-board centrifuge 0-g

1 g

g

1-g for 3 hrs

SpaceBiology 29Plant Biology in Space — Results

• The reproductive phase is completed in microgravity when theculture conditions (gas and liquid exchanges) are adequate

• Whether or not a seedling growing from the beginning inmicrogravity can flower and produce normal seeds remains amatter of debate

• On-board centrifuge experimentshave demonstrated that theminimum force that is sensed byplant organs is in the range of1/1000th of g

• The root is able to perceive itsorientation with respect to a linearacceleration vector and to generatea signal of curvature in less than 30 seconds

SpaceBiology 30Plant Reproduction• LDEF: Long-Duration Exposure Facility

– 12 million tomato seeds in space for 6 years– Post-flight measurement of germination

Germination %Flight 73.8Ground Control 70.3

– Conclusion: Seeds remain viable in space

• Cell Division and Chromosomal Damage inembryos of cultured Hemerocallis (daylily)

Ground Flight Cells in division (%) 2.6 0.4Cells in metaphase (%) 31.3 11.3

Chromosome damage (%) 0 1.7 Double nuclei (%) 0 3.1

– Conclusion: The space environment(microgravity and/or radiation) results in reduced cell division and increasedchromosomal damage

SpaceBiology 31Plant Reproduction

• Recent experiments showed that reproduction proceedednormally through the stage of an immature seed

• Past failures were probably due to less than adequatehorticultural conditions

Pre-flight

Post-flight (11 days)

Flowers formed in spacewere normal in appearance

Pollen germinated and pollentubes grew towards style

Seed pod(silique)formed inspace

Pistil of flowergrown in space

Ovules from siliquesformed in space

SpaceBiology 32Bioprocessing• Biotechnology is an applied biological science

that involves the research, manipulation, and manufactoring of biological molecules, tissues, and living organisms

• Biotechnology has a critical role in health,agriculture, and environmental protection

• Space biotechnology is focused on protein crystal growth, cell andtissue culture, and the fundamental mechanisms of cell growthand secretion

• Microgravity offers a unique environment that re-orders the forcesexerted on cells. The response of cells to this re-ordering providesnovel insights into fundamental cellular mechanisms. Cellsunloaded from gravity may perform to our advantage in tissueformation

• The response of cells to microgravity, combined with advances inmolecular biology and genetics, offers the opportunity to explorenew strategies in applied science and contribute to public health

Flowering on board the ISS (NASA)

SpaceBiology 33Biotechnology in Microgravity

•• Research AreasResearch Areas– Protein crystal growth– Cell and tissue culture– Manufacture of biological materials

•• Research ThemesResearch Themes– Molecular structure of proteins

and viruses– Structure-based drug design– In-vitro drug testing– New technologies for

bioprocessing (in particularisolation and purification)

Satellite Tobacco Mosaic Virus(STMV) crystals grown in 0 g

Lysozyme x150

SpaceBiology 34ESA Biolab onboard ISS

Cou

rtesy

of E

SA

SpaceBiology 35ISS Centrifuge Accommodation Module

SpaceBiology 36Biology Research onboard ISS

* can be used on the 2.5-m diameter centrifuge (0.01-2.0 g)** equipped with internal 0.01-1.5 g centrifuges

• Cell Culture Unit* Research in cell and tissue biologyCapability to maintain and monitor animal and plant cell and tissue culture for up to 30 days

• Aquatic Habitat* Egg to egg generation studies for examination of life stages. Can accommodate small fresh water organisms for up to 90 days

• Advanced Housing for up to 6 rats or 12 pregnant mice Animal Habitat* for studies of mammals development

• Plant Research Studies of growth and developmentUnit* for plant specimens up to 30 cm (root+shoot)

• Insect Habitat** Multigenerational and radiation biology• Egg Incubator** Incubation and development of small reptilian

and avian eggs prior to hatching

SpaceBiology 37Research Opportunities

• International Life Science Research Announcement(ILSRA) coordinated between the ISS partners

• This ILSRA is released annually and includes severalresearch opportunities

– Life Sciences themes using the ISS– Research in biology using sounding rockets– Research in biology using biosatellites– Utilization of the bed rest facilities to prepare for

human physiology projects on the ISS– Utilization of the centrifuge facilities to prepare for

artificial gravity projects– Utilization of the specific environment and living

conditions of polar stations

SpaceBiology 38Reading Material

• Clément G (2005) Fundamentals of Space Medicine.Dordrecht: Springer

• Clément G, K Slenzka (2006) Fundamentals of Space Biology.El Segundo: Microcosm Press, New York: Springer

• Dutemple L (2000) The Complete Idiotʼs Guide to Life Sciences.Indianapolis, IN: Alpha Books

• Oser H, Battrick B (eds) (1989) Life Sciences Research in Space.Noordwijk: ESA Publication Divisions, ESA SP-1105

• Future Biotechnology Research on the International Space Station(2000). Commission on Physical Sciences, Mathematics, andApplications, Space Studies Board. Washington DC: The NationalAcademies Press. Available online at URL:

http://www.nap.edu/books/03090697/html• http://astrobiology.arc.nasa.gov/genomics

/technologies/available_hardware.html