(Press-News.org) At work on the International Space Station, researchers studying plant and cell growth in space encountered a challenge. Imaging revealed interesting spaceflight-associated root morphologies. They needed to fix the tissues for further study back on Earth, but conventional fixation methods require separate fixatives depending on whether the sample is intended for molecular or morphological study. If the scientists wanted to study how spaceflight affected patterns of gene expression central to morphological patterns of cell growth, they needed a fixation method that would allow them to study both perspectives.
Most scientists at work in the laboratory rely on protocols that have been developed without the need for restrictions on the amount of space, time, or reagents they use. For scientists conducting experiments in spaceflight, time and resources are strictly regulated and limited, and researchers must know in advance which protocols will maximize the usefulness of the data they collect.
University of Florida professors Anna-Lisa Paul and Robert Ferl and colleagues are collaborating with the National Aeronautics and Space Administration (NASA) to understand plant growth and development in spaceflight. Along with lead author and graduate student Eric Schultz, they have developed a single fixation protocol for use in space that allows plant material to be used for multiple experimental applications. Their new protocol for sample preparation was tested on Arabidopsis tissues harvested on the International Space Station and is described in the August issue of Applications in Plant Sciences (available for free viewing at http://www.bioone.org/doi/pdf/10.3732/apps.1300034).
Because of limitations in astronaut crew time and orbital resources, previous spaceflight fixation protocols were designated as either molecular or morphological, due to the separate fixatives required for each application. Tissues for morphologic study were fixed in 3% glutaraldehyde (or a similar solution), and tissues for molecular study were fixed in the tissue storage reagent RNAlater. RNAlater has not commonly been used as a morphologic fixative, as it can produce unclear images with high background staining.
The new method developed by Schultz et al. puts RNAlater-fixed samples through a desalination process to return them to a fresh-like state, and then uses low-temperature scanning electron microscopy (cryo-SEM) to preserve tissues for imaging. Because few laboratories have access to the necessary equipment for cryo-SEM, the authors tested and developed a protocol that emulates cryo-SEM using standard SEM equipment and, importantly, that results in minimal tissue damage.
Although it was developed to address specific constraints for spaceflight experiments, Paul notes that their new method is broadly applicable. "There are a lot of situations where biologists want to collect samples in extreme situations. In our case—a space vehicle orbiting the Earth."
The new protocol maximizes the amount of data obtained from a single sample and allows for the concomitant examination of both molecular and morphological features. Using a single fixation protocol, direct comparisons between changes in morphology and altered gene expression can be made. Such an analysis not only makes full use of samples and replicates but also enables a robust analysis of the relationship between heredity and development. "Putting two tools together, it is powerful to look at the morphology in conjunction with the genes that are being expressed," says Paul.
The new protocol boasts low costs and high accessibility, and has wide application to any situation where recovery of biological resources is limited. Notably, this includes researchers collecting and preserving samples in the field, where space for materials is at a premium. "In places where sampling is limited, difficult, or expensive, the use of preservatives allows for more routes to analysis," notes Ferl.
INFORMATION:
Applications in Plant Sciences (APPS) is a monthly, peer-reviewed, open access journal focusing on new tools, technologies, and protocols in all areas of the plant sciences. It is published by the Botanical Society of America (http://www.botany.org), a non-profit membership society with a mission to promote botany, the field of basic science dealing with the study and inquiry into the form, function, development, diversity, reproduction, evolution, and uses of plants and their interactions within the biosphere. The first issue of APPS published in January 2013; APPS is available as part of BioOne's Open Access collection (http://www.bioone.org/loi/apps).
For further information, please contact the APPS staff at apps@botany.org.
Plants in space: A novel method for fixing plant tissue samples maximizes time, resources, and data
2013-09-12
ELSE PRESS RELEASES FROM THIS DATE:
The eyes have it
2013-09-12
More than one billion people worldwide rely on fish as an important source of animal protein, states the United Nations Food and Agriculture Organization. And while fish provide slightly over 7 per cent of animal protein in North America, in Asia they represent about 23 per cent of consumption.
Humans consume low levels of methylmercury by eating fish and seafood. Methylmercury compounds specifically target the central nervous system, and among the many effects of their exposure are visual disturbances, which were previously thought to be solely due to methylmercury-induced ...
Study provides insights on protecting world's poor from climate change
2013-09-12
The worst impacts of climate change on the world's poorest fishing communities can likely be avoided by careful management of the local environment and investing in the diversification of options for local people, according to the Wildlife Conservation Society and James Cook University.
Climate change is already putting pressure on fishers who depend on nature for their livelihoods. In a new study, scientists found large differences in the potential to adapt based on the local mixture of social and environmental characteristics, requiring a variety of management approaches ...
Health care safety net catches suburban poor
2013-09-12
CHICAGO --- A new study shows significant health benefits for uninsured people living under the federal poverty level in the suburbs when they receive access to primary care.
Uninsured residents in a suburban collar county of Chicago reported a big improvement in their health status and increased their preventive care and screenings after one year of access to primary care, reports Northwestern Medicine research.
The study illustrates the potential benefits of the Affordable Care Act (ACA) implementation and a promising solution to accessible health care for what are ...
Researchers identify ancient ancestor of tulip tree line
2013-09-12
BLOOMINGTON, Ind. -- The modern-day tulip tree, state tree of Indiana as well as Kentucky and Tennessee, can trace its lineage back to the time of the dinosaurs, according to newly published research by an Indiana University paleobotanist and a Russian botanist.
The tulip tree, Liriodendron tulipfera, has been considered part of the magnolia family. But David Dilcher of Indiana University Bloomington and Mikhail S. Romanov of the N.V. Tsitsin Main Botanical Garden in Moscow show that it is closely related to fossil plant specimens from the Lower Cretaceous period.
Their ...
Everyday sadists take pleasure in others' pain
2013-09-12
Most of the time, we try to avoid inflicting pain on others — when we do hurt someone, we typically experience guilt, remorse, or other feelings of distress. But for some, cruelty can be pleasurable, even exciting. New research suggests that this kind of everyday sadism is real and more common than we might think.
Two studies led by psychological scientist Erin Buckels of the University of British Columbia revealed that people who score high on a measure of sadism seem to derive pleasure from behaviors that hurt others, and are even willing to expend extra effort to make ...
Central mechanism underlying electroacupuncture effects visceral hypersensitivity
2013-09-11
Irritable bowel syndrome patients extensively suffer from chronic visceral hypersensitivity, with involvement of all levels of the brain-gut axis, as well as various neurotransmitters. Chronic visceral hypersensitivity can occur in the periphery, spinal cord and central nervous system, which has been shown to be the main pathophysiological mechanism underlying abdominal pain in patients with irritable bowel syndrome. Acupuncture at Tianshu (ST25) and Shangjuxu (ST37) has been reported to relieve visceral hypersensitivity for irritable bowel syndrome. Xinxin Guo and colleagues ...
Anti-inflammatory and anti-thrombogenic effects of atorvastatin in acute ischemic stroke
2013-09-11
The population of northeastern China has a high incidence of ischemic stroke. Previous studies have shown that intracranial large-artery atherosclerosis is one of the main causes of ischemic stroke, and that the mechanisms are related to inflammation and thrombosis of the affected arteries. A recent study by Lianqiu Min and colleagues from Liaoning Medical University observed the effects of atorvastatin treatment in 89 patients from northeastern China with acute ischemic stroke caused by intracranial large-artery atherosclerosis by measuring changes in the levels of markers ...
The mechanism of astragaloside IV promoting sciatic nerve regeneration
2013-09-11
Astragaloside IV, the main component of the traditional Chinese medicine astragalus membra-naceus, has been shown to inhibit inflammation, oxidation, and apoptosis, and exerts immu-noregulatory effects. Xiaohong Zhang and colleagues from School of Pharmacutical Sciences, Jilin University investigated whether astragaloside IV could promote the repair of injured sciatic nerve. Denervated sciatic nerve of mice was subjected to anastomosis. The mice were intraperitoneally injected with 10, 5, 2.5 mg/kg astragaloside IV per day for 8 consecutive days. The researchers found that ...
Tiny diamonds to boost treatment of chemoresistant leukemia
2013-09-11
Singapore, 11 September 2013 – By binding multiple molecules of a common leukemia drug with nanodiamonds, scientists from the National University of Singapore (NUS) and University of California, Los Angeles (UCLA) managed to boost the delivery of the drug to leukemic cells and retain the drug within the cells to combat the cancer.
This novel discovery, reported for the first time, addresses one of the major challenges in the treatment of leukemia where the cancer cells develop ways to pump drugs out of the body before they can do their job, particularly after they are ...
Map of galactic clouds where stars are born takes shape
2013-09-11
SYDNEY: A UNSW-led team of astronomers has begun to map the location of the most massive and mysterious objects in our galaxy – the giant gas clouds where new stars are born.
Using a telescope at Coonabarabran that narrowly escaped devastation in a recent bushfire, the team identifies the galactic clouds of molecular gas - which can be up to 100 light years across - from the carbon monoxide they contain.
"On Earth, carbon monoxide is poisonous – a silent killer. But in space, it is the second most abundant molecule and the easiest to see," says Professor Michael Burton, ...