Recent advances in DNA sequencing have made it relatively easy to acquire the full genotype of an individual, but it is equally important to match those genes to their functions. One useful step is to build up a ‘metabolic phenotype’ outlining all the processes operating to sustain the individual’s life.
Jun Kikuchi and co-workers at the RIKEN Plant Science Center in Yokohama, Yokohama City University and Nagoya University have developed a systematic method to characterize metabolic pathways in plants and animals. Their method involves measuring nuclear magnetic resonance (NMR) of samples and comparing them against an extensive database of molecules associated with metabolism, known as metabolites.
NMR works by detecting the response of atoms or molecules to a magnetic field. Normal carbon atoms show no response, so cells must be labeled with the stable isotope carbon-13.
Kikuchi and co-workers fed Arabidopsis plants and silkworm larvae with glucose and amino acids that had carbon-13 atoms in place of the normal carbon. After this incubation process, almost all the metabolites produced by the cells contained carbon-13. Importantly, carbon-13 displays a slightly different magnetic response depending on the structure of the molecule it is in, so each metabolite provided a unique NMR spectrum.
The researchers compared the spectra of their samples against a database of spectra for known metabolites. They identified 57 unique metabolites in the silkworm larvae, and 61 in Arabidopsis.
The team then used a technique called Principal Component Analysis to identify correlations between metabolites in the silkworm. These correlations represent metabolic pathways related to key stages in the larval development.
In particular, the results showed a random pattern of metabolic pathways over the first six days of the study, giving way to some correlations later. This suggests that better metabolic organization emerged as the larvae grew.
The study represents the first ‘top-down’ method of analyzing whole metabolic pathways. It provides a macroscopic phenotype describing cells, fluids and tissues, rather than looking at specific reactions from the atomic level upwards. What’s more, the technique is relatively quick.
“After an NMR measurement, typically taking about 1 hour, computation of the metabolic pathways finishes within half a day,” explains Eisuke Chikayama, who wrote the team’s recent paper in PLoS ONE (1).
Chikayama is also hopeful that the technique could be extended to other plants and animals, including humans.
“Our method is not restricted to any particular organism, if adequate NMR samples are ready.”
1. Chikayama, E., Suto, M., Nishihara, T., Shinozaki, K., Hirayama, T. & Kikuchi J. Systematic NMR analysis of stable isotope labeled metabolite mixtures in plant and animal systems: Coarse grained views of metabolic pathways. PLoS ONE 3(11), e3805 (2008).
The corresponding author for this highlight is based at the RIKEN Metabolomics Research Group: Advanced NMR Metabomics Research Unit
Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University
Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences