While DNA (deoxyribonucleic acid) provides an identical genetic blueprint in every cell, RNA (ribonucleic acid) decodes genetic instructions that turn protein molecules on and off in different cell types.
The new tagging method, tested in a variety of subsets of Drosophila brain cells, is described in a paper put on line ahead of regular publication by the journal Nature Methods. Instead of scientists needing to physically separate cell types, they now can inject a chemically modified gene from the one-celled organism Toxoplasma gondii and activate it in only one cell type within a tissue. Only newly generated RNA in this cell type is then tagged and isolated.
"By analyzing RNA from different cell types, we can begin to understand how cellular differences are generated," said lead author Michael R. Miller, a National Science Foundation-funded doctoral student in the lab of Chris Doe, a UO biologist and Howard Hughes Medical Institute (HHMI) investigator. "Our new TU-tagging method should be useful for isolating cell-type specific RNA from other organisms, including mammals, and should be useful in broad areas of research including studies of development, neurobiology and disease."
The new non-toxic, non-invasive method makes it possible to "listen in" to the messages -- in fact, messenger RNA -- that the nucleus is sending each cell, without perturbing the cell, Doe said. "It is much like eavesdropping on a phone conversation, rather than pulling the person out of the house for questioning. The cell has no idea that its RNAs are being 'tagged' for isolation and study. That's good, because we get a more accurate idea of what the cell is saying."
That, Doe added, could be helpful for 'listening' to host cells before and after the initiation of a disease to determine how cells respond, or, for example study healthy immune cells versus bacterially-challenged immune cells or neurons before they learn a task and after they learn a task to determine what changes in the cell are caused by the experience.
The new UO-developed tool builds on work led by co-author Michael D. Cleary, who as a doctoral student at Stanford University unveiled the T. gondii-based approach for use in analyzing RNA synthesis and decay in 2005 in Nature Biotechnology. Cleary, now a faculty member at the University of California, Merced, worked on the UO project as a postdoctoral fellowship funded by the National Institutes of Health and HHMI.
Cleary's group built its tool with the enzyme uracil phosphoribosyltransferase (UPRT), a nucleotide salvage enzyme that prepares nucleotides for incorporation into newly synthesized RNA. By altering the nucleotide analog 4-thiouracil, the UPRT enzyme caused RNA to become tagged with thiouracil (TU), allowing the "TU-tagged" RNA to be purified from untagged RNA.
In Doe's lab, Miller, Cleary and research technician Kristin J. Robinson of the UO's institutes of Neuroscience and Molecular Biology manipulated Drosophila so that they would only express UPRT in specific target cells. The group tested the new approach in embryos, larvae and adults using microarray technology to detect cell type-specific gene expression. The researchers say the method should work in other systems, including vertebrates, by using gene transfer, retroviral delivery, electrical pulses of molecules through cell membranes, or messenger RNA injection.
About the University of Oregon
The University of Oregon is a world-class teaching and research institution and Oregon's flagship public university. The UO is a member of the Association of American Universities (AAU), an organization made up of the 62 leading public and private research institutions in the United States and Canada. The University of Oregon is one of only two AAU members in the Pacific Northwest.
Sources: Chris Doe, professor of biology and HHMI investigator, 541-346-4877, email@example.com; Michael R. Miller, UO doctoral student, firstname.lastname@example.org
Jim Barlow | Newswise Science News
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy